JAEA-Review 2007-060

JAEA Takasaki Annual Report 2006
(Ed.) Shigeru TANAKA

Takasaki Advanced Radiation Research InstituteJapan Atomic Energy Agency
Watanuki-machi, Takasaki-shi, Gunma-ken(Received December 27, 2007)
JAEA Takasaki annual report 2006 describes research and development activities performed
from April 1, 2006 to March 31, 2007 with Takasaki Ion Accelerators for Advanced Radiation
Application (TIARA, four ion accelerators), and electron/gamma-ray irradiation facilities (anelectron accelerator and three 60 Co gamma-ray irradiation facilities) at Takasaki Advanced
Radiation Research Institute, Japan Atomic Energy Agency (JAEA Takasaki). These activities
are classified into four research fields: 1) space, nuclear and energy engineering, 2)
environmental conservation and resource security, 3) biotechnology and medical application, and
4) advanced materials, analysis and novel technology. This annual report contains 186 reports
consisting of 178 research papers and 8 status reports on operation/maintenance of the irradiation
facilities described above, and a list of publications, related press-releases, TV programs, patents,
and the type of research collaborations as Appendices.

Keywords: TIARA, Ion Accelerators, Electron Accelerator, Gamma-ray Facilities, Nuclear andEnergy Engineering, Environment Conservation, Resource Security, Biotechnology,
Medical Application, Advanced Materials, Analysis, Novel Technology, Materials forSpace, Semiconductors, Inorganic Materials, Organic Materials, Functional Materials,
Radiation Chemistry, Radiation Biology, Radioisotope Production, Nuclear Chemistry,
Material Analyses, Solid State Physics, Microbeam Technology, Accelerator
Technology, Accelerator Operation, Safety Control(Editorial committee) Shigeru TANAKA, Hisayoshi ITOH, Atsushi TANAKA,
Tomihiro KAMIYA, Kazumasa NARUMI, Takuji KOJIMA, Kiyoshi KAWATA,
Yoshiteru NAKAMURA and Hiroyuki TACHIBANAiJAEA-Review 2007-060

高崎量子応用研究所研究年報 2006
日本原子力研究開発機構 高崎量子応用研究所(編) 田中 茂（２００７年１２月２７日受理）
高崎量子応用研究所研究年報 2006 は、同研究所にある TIARA 施設（イオン加速器 4 基）及び電子･ガンマ線照射施設（電子加速器 1 基、 60Co ガンマ線照射施設 3 棟）を利用して2006 年 4 月 1 日から 2007 年 3 月 31 日までの間に行われた研究・技術開発成果をまとめたものである。この研究年報には、１）宇宙・原子力・エネルギー、２）環境・資源、３）バイオ技術・医学応用、４）先端材料・計測・基盤技術の 4 分野に分類した 178 編の論文及び 8 編の施設の運転・管理状況報告からなる合計 186 編を収録する。また、論文リスト、
新聞発表、テレビ放映、出願特許、及び研究実施形態・利用施設の一覧表を付録として含む。

高崎量子応用研究所：〒 370-1292 群馬県高崎市綿貫町 1233
編集委員：（著者代表）田中 茂、伊藤 久義、田中 淳、神谷
鳴海 一雅、小嶋 拓治、河田ii

靖、中村 義輝、橘富裕、宏行

JAEA-Review 2007-060

PREFACEThis report covers research and development activities in Takasaki Advanced Radiation
Research Institute, JAEA, during the period from April 2006 to March 2007, conducted withTIARA (Takasaki Ion Accelerators for Advanced Radiation Application), electron beam andCo-60 gamma-ray irradiation facilities.
One hundred eighty seven papers are appeared in this annual report in the fields of1) Space, Nuclear and Energy Engineering,2) Environmental Conservation and Resource Security,
3) Biotechnology and Medical Application,4) Advanced Materials, Analysis and Novel Technology,5) Status of Irradiation Facilities.
In the field of Space, Nuclear and Energy Engineering, the radiation resistance of solar
cells and integrated circuits newly developed for space application has been evaluated using
high-energy electrons, protons and heavy ions. Experimental and theoretical investigationsof transient currents induced in typical device structures such as SOI (silicon on insulator) byenergetic ions have been performed for clarifying mechanisms behind single event
phenomena in order to develop prediction methods of the reliability of semiconductor devices,which will be used in radiation environment. Radiation resistant devices have also beendeveloped using wide band-gap semiconductors like SiC and GaN. Radiation degradation oforganic materials, e.g., insulating materials in superconducting coils of ITER, coaxial cables
for J-PARC, and grease for the equipments of nuclear-cycle reprocessing have been examined
for aiming at their practical usage. Radiation effects involving irradiation assisted stresscorrosion cracking (IASCC) in structural materials of fusion, fast breeder and light water
reactors have been intensively investigated using TIARA for securing reactor safety. In
addition, high quality polymer electrolyte membranes have been fabricated using ion beams,
electron beams and gamma-rays for their application to fuel cells.
In the field of Environmental Conservation and Resource Security, metal ion adsorbents
have been developed with radiation grafting technique for removing toxic elements such as
Cd, Pb and B in industrial waste water. R&D of graft adsorbents based on plant-derived
polymers like polylactic acid (PLA) and carboxymethylcellulose (CMC) has been started.
Radiation grafting technique has also been applied to improve the properties of materials forindustrial use; low power-loss millimeter-wave planar antennas and high quality rubber
wipers for automobiles have been successfully developed. Biodegradable hydro-gels andpolymers from CMC and PLA have been investigated using radiation cross-linking, leading to
the success in fabricating novel elastic CMC gels and elastic PLA materials with high heat
resistance. Concerning environmental purification using electron beams and gamma-rays,
new process technologies have been developed for the decomposition and removal of trace
amount of pollutants such as formaldehyde in sterilization gas, dioxin wastes and endocrine
disrupting chemicals.
In the field of Biotechnology and Medical Application, the ion beam breeding technique
has been applied for many varieties of plants and microorganisms such as flower, crop,
vegetable, yeast, alga and fungus. Functional analyses of radiation-response proteins of theradioresistant bacterium and the elucidation of characteristics of ion beam-induced damage
and mutation have been progressed. Molecular mechanisms in radiation-induced bystanderiii

JAEA-Review 2007-060

effects were investigated in normal and cancer cells using heavy-ion microbeams in the
aspects of initiators/mediators and the role of gap junction. The effect of ionizing radiationon the food-NaCl associative learning behavior in Caenorhabditis elegance was also
investigated. Compartment model was applied to the positron imaging of a tobacco leaf andsucceeded in obtaining parametric imaging of two photosynthetic processes,
photoassimilation and sucrose-export. A new radionuclide for medical application, Br-76,
was produced by using AVF cyclotron and examined for the diagnosis of cancer by positronemission tomography, PET. Clarification of the dynamics of anticancer drug was studied byanalyzing trace elements in tumor cells using the in-air micro-PIXE system.
In the field of Advanced Materials, Analysis and Novel Technology, development ofhydrogen gas sensor using tungsten trioxide (WO3) has been conducted; it was founded thation irradiation to WO3 films improved their gasochromic coloration by introducing oxygen
vacancies. In order to measure the three-dimensional distribution of elements in biologicalsamples, such as carbon, hydrogen, and oxygen using the in-air micro PIXE system, STIM
(Scanning Transmission Ion Microscopy) / CT (computed tomography) method wasdeveloped and introduced to the system; three-dimensional reconstruction of an insect’s head
was successfully obtained using all tomograms with the system. All-permanent-magnet type
ECR ion source (LECR) has been developed since 2003, and beam current of O7+ wasincreased from 0.6 to 1.8 μA by the modification of the LECR in 2006. Negative Ge cluster
ions were generated by a Cs sputter ion source, and Ge clusters up to Ge4 at the beam currentof nano ampere order was extracted from the source. Three-dimensional micro structures
were fabricated with the Proton Beam Writing (PBW) technique using protons at two different
beam energies of 1.2-and 3.0-MeV impinging on a layer of negative resist material. In thedevelopment of monitor and dosimeter for radiation, measurement technique of two
dimensional dose distribution was developed by using B3 film dosimeters and a PC-scanner.
All the accelerators in TIARA, namely the AVF cyclotron, the 3-MV tandem accelerator,
the 3MV single-ended accelerator and the 400-kV ion implanter, have been operated steadily
as well as an electron accelerator and irradiation systems in Co-60 gamma-ray irradiation
facilities. Especially, the cyclotron has been operated in this fiscal year providing ion-beams
to all users perfectly without any cancellation of machine time, although there occurred 324
machine troubles. The total operation time of the cyclotron from the first-beam provision
reached 50,000 h in April 2007, as the result of such continuous back-up efforts.

Hideki Namba,
Director General
Takasaki Advanced Radiation Research InstituteJapan Atomic Energy Agency

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This is a blank page.

JAEA-Review 2007-060

1-01

Effect of Base-layer Carrier Concentration on
Radiation Resistance of AlInGaP Solar Cell

a)

a)

b)

c)

c)

c)

C. Morioka , M. Imaizumi , T. Takamoto , T. Ohshima , S. Sato , H. Miyamotoa)and K. Kibea)b)Institute of Aerospace Technology, JAXA, Solar System Division, Sharp Corporation,c)Environment and Industrial Materials Research Division, QuBS, JAEA
of the AlInGaP 1J solar cells due to 1MeV-electron and
3MeV-proton irradiations, respectively. In the case ofdegradation of Isc, there seems to be no significant
dependency on the carrier concentration, while the cell withthe concentration of 3×1017 cm-3 degrades greater than thosewith the concentration of the order of 1016 cm-3.
These results indicate that the minority-carrier diffusion
length in the p-AlInGaP base layer and its radiation
degradation are not affected by the base-layer carrier
concentration between 1×1016 cm-3 and 3×1017 cm-3. On theother hand, the carrier removal effect due to the irradiation,
which results in the decrease in built-in potential at the
AlInGaP n/p junctions, is greater when the base-layer carrier
concentration becomes in the order of 1017 cm-3.
Reference
1) C. Morioka et al., Proc. of 4th World Conference on
Photovoltaic Ener. Conv., Waikoloa, 2006, pp.1846-1849.
1.0

1.0

Remaining Factor of Isc

Remaing Factor of Isc

Optimum epitaxial layer structure of an AlInGaP solar
cell as a top subcell in a triple-junction (3J) space solar cellhas been studied. In 2006, the base-layer carrier
concentration in AlInGaP single-junction (1J) solar cells
was varied in order to clarify the suitable carrier
concentration for radiation resistance of the cell.
AlInGaP 1J solar cell epitaxial wafers were grown bymetal-organic vapor phase epitaxy (MOVPE). The carrier
concentration in base-layer was varied for 1×1016 cm-3,
3×1016 cm-3 and 3×1017 cm-3. Solar cells were fabricatedfrom the wafers. However, anti-reflection coating was notformed on the surface of the cells to avoid the effect ofdifference in reflectance. The cell size is 1cm×1cm. The
cells were irradiated with 1MeV electrons (nitrogenambient) and 3MeV protons (in vacuum) at room
temperature.1)
Figures 1 and 2 depict the radiation degradation of theshort-circuit current (Isc) and the open-circuit voltage (Voc)

0.9
0.8
1e16
3e16
3e17

0.7
0.6

14

15

10

10

16

10

0.8
0.6
0.4
1e16
3e16
3e17

0.2
0.0

1MeV Electron Fluence [cm ]

11

10

1.0
0.9
0.8

0.6

1e16
3e16
3e17
14

10

10

15

12

13

10

14

10

(a) Short-circuit current (Isc)Remaining Factor of Voc

Remaining Factor of Voc(a) Short-circuit current (Isc)

0.7

10

3MeV Proton Fluence [cm-2]

-2

16

10

1.0
0.8
0.6
0.4
1e16
3e16
3e17

0.2
0.0

11

10

10

12

13

10

14

10

1MeV Electron Fluence [cm ]3MeV Proton Fluence [cm-2](b) Open-circuit voltage (Voc)(b) Open-circuit voltage (Voc)

Fig.1 Degradation of short-circuit current and open-circuit
voltage of AlInGaP solar cells with different base-layer
carrier concentration due to 1MeV electrons.

Fig.2 Degradation of short-circuit current and open-circuit
voltage of AlInGaP solar cells with different base-layer
carrier concentration due to 3MeV protons.

-2

－ 5 －

JAEA-Review 2007-060

1-02 Evaluation of Radiation Hardened Logic Circuits
Utilizing 0.15μm SOI Technology for Space Application
a)

a)

a)

a)

b)

H. Shindou , M. Midorikawa , Y. Satoh , S. Kuboyama , T. Hirao and T. Ohshimab)a)Institute of Aerospace Technology, Japan Aerospace Exploration Agency (JAXA),b)
Environment and Industrial Materials Research Division, QuBS, JAEA

Semiconductor devices with Silicon On Insulator (SOI)
technology are utilized for high-performance and low-powerelectronics such as computer servers for high-end
commercial markets. SOI is a layered structure consisting ofa thin layer of silicon mounted on an insulating substrate.
The typical cross section image is shown in Fig.1. SOI
technology is also very attractive as semiconductor devices
for space application. SOI devices are expected to have an
advantage over equivalent bulk technology devices forSingle-Event Effects (SEEs) caused by heavy ions andhigh-energy protons because the sensitive volume for SEEs
is much smaller than that of bulk Si devices. In JAXA, now
we continuously perform the design and evaluation ofradiation hardened logic circuits utilizing 0.15μm fully
depleted SOI process technology1). This study is
indispensable in order to develop next generation
semiconductor devices for space application such as
high-speed
Microprocessors(MPUs)
andField
Programmable Gate Arrays (FPGAs).
This year, several kinds of radiation hardened logic
circuits such as latch and flip flop were designed andevaluated. In this report we describe the evaluation resultsof latch circuit as a representative case. Two types ofradiation hardened latch circuit (Basic type and Optimizedtype) were designed and installed in the test chips. In
general, Single Event Transient (SET) pulse is generated
when an ion particle hit on the p-n junction of transistors.

Input
GND

outputn+
BOX(SiO2)

The propagation of this pulse noise leads to the malfunctionof logic circuit (i.e. SEE). For SOI technologies, it ispossible to eliminate the SET pulse generation on the output
terminal by using circuit techniques 1). Figure 2 shows theconcept of the radiation hardened inverter logic circuits withredundant transistors. By using this, various types ofradiation hardened logic circuit can be constructed. For thebasic type latch circuit, SET-free inverter circuit is fully
applied on the data input logic and the inverter loop.
However the area, power consumption, speed penalties are
too large compared to the conventional latch circuits. For
the optimized type, some redundant p-type transistors are
removed in order to minimize the penalty mentioned above.
Test chips were fabricated with a 0.15 μm fully depleted
SOI commercial process at OKI (Tokyo, Japan). Figure 3
shows the pictures of test device. In this chip, each kind oflatch circuit composes the 4kbit memory array.
Kr and Xe ion irradiation test results are shown in Table 1.
Some amount of SEU was observed only when Xe ion
irradiated. It was confirmed that both types of latch circuits
have a very good radiation tolerance. We plan to continue
this study in order to construct the radiation hardened logic
cell library for space SOI.
Reference
1) A. Makihara et al., IEEE Trans. Nucl. Sci., Vol. 52, 2524
(2005).

VDD
p+p-Substrate

Fig. 1 Cross section image of SOI device

Fig. 3 Outline of the testAAY

Redundant
Tr Pairs

Y

Conventional inverter
circuit

Radiation hardened
inverter circuit (SET-free)Fig. 2 Concept of the radiation hardened inverter
logic circuits with redundant transistors－ 6 －Table 1 Heavy ion irradiation test result
Ion
Fluence# of Errors
2[particles/cm ]BasicOptimized
type
type
Kr

1.33E+800Xe

1.50E+8

3*

49*These errors may be attributable to considerable
degradation caused by local total ionizing dose
effect.

JAEA-Review 2007-060

1-03 Transportation of Charge Induced in MOS
Capacitor by Heavy-ion Irradiation
a)

a)

b)

T. Hirao , S. Onoda , Y. Takahashi , K. Ohnishib)and T. Ohshimaa)a)Enviroment and Industrial Materials Research Division, QuBS, JAEA,b)
College of Science and Technology, Nihon University

One of the most detrimental effects on semiconductor
devices in radiation environments is single-event effects(SEEs). When a high-energy heavy ion strikes the device,electron-hole (e-h) pairs are generated along the ion-track
and they lead to transient currents at the terminal of devices.
Musseau et al. proposed that the silicon-on-insulator(SOI) is one of the most promising structures to achieve
higher SEE tolerant devices, because the charge collection
can be suppressed by the existence of a buried oxide layer 1).
However, the anomalous charge collection in the SOI device
was reported recently 2). This fact suggests that dense
charges generated under a buried oxide contribute to thecharge collection. Therefore it is important to make clear the
charge collection mechanisms through an insulation (oxide)
layer due to heavy ion irradiation. In a previous study, we
have measured transient currents induced through an oxide
layer by ion incidence using metal oxide semiconductor(MOS) capacitors to understand the charge collection
mechanisms in SOI devices. As a result, the transientcurrent induced in MOS capacitors can be qualitatively
interpreted in terms of displacement current 3). However, thequantitative analysis has not yet done.
In this report, we perform numerical simulations ontransient currents induced in MOS capacitors using an
optimized physical model, and compare calculated results toexperimental results.
The MOS capacitors used in this study are fabricated on
p-type Si substrates. The concentration of boron acceptors inthe substrate is 4.63x1015 /cm3. The oxide layer at a
thickness of 31 nm was formed using dry oxidation at 1050
o
C for 30 min. Aluminum was applied as the gate metal.
Heavy ion irradiation experiments were carried out using
the 3MV tandem accelerator at TIARA. The transientcurrents induced in the MOS capacitors by 15 MeV-oxygenion incidence were collected by transient ion beam induced
current (TIBIC) measurement system with single ion hit(SIH) system.
The transient currents were simulated by using theTechnology Computer Aided Design (TCAD) version 10
provided by Synopsys. The DESS package in TCAD wasused to simultaneously solve the Poisson and e-h continuity
equations under the cylindrical symmetry (quasi-three
dimensional) conditions. The following models wereassumed in all simulations: (1) Fermi–Dirac statistics, (2)bandgap narrowing, (3) mobility model dependent on
doping concentration, and carrier density, (4) high fieldsaturation, and (5) incomplete ionization. In addition, since

the ion initial track structure strongly affects the transientcurrent, the distributions of e-h pairs are calculated byconsidering the δ-electron production with MeV ion
penetration and keV δ-electron transmission theory, insteadof the cylindrical track structure generally accepted in
TCAD simulations.
Figure 1 shows the comparison of the experimental
results with the simulated results. The total collectedcharges do not show strong bias dependence and slightly
decrease with increasing bias. On the other hand, as for the
peak currents, the values increase with increasing bias. As aresult, the peak currents and the total collected charges
obtained by time integration of transient currents agree wellwith the measured values, errors being less than 10%.

Fig.1 Comparison of the experimental results withsimulated results. Bias dependence Peak Current andTotal Collected Charge.

References
1) O. Musseau et al., IEEE Trans. Nucl. Sci., Vol. NS-43,
No.2, p. 603 (1996)
2) P.E. Dodd et al., IEEE Trans. Nucl. Sci., Vol. NS-48,
No.6, p. 1893 (2001)
3) Y. Takahashi et al., The IEICE Trans. Electron. Vol.
J89-C, No.3, p. 104 (2006).

－ 7 －JAEA-Review 2007-060

1-04 Heavy-ion Induced Current in Silicon-on-insulator
Based Devices
a)

a)

a)

a)

a)

a)

K. Ohnishi , Y. Takahashi , Y. Nakajima , T. Nagasawa , M. Fugane , R. Imagawa ,
a)
b)
b)
a)
K. Nomoto , T. Hirao , S. Onoda and K. Mishimaa)b)

Nihon University, Environment and Industrial Materials Research Division, QuBS, JAEA

In order to clarify the charge collection mechanism through a buried oxide layer in SOI structure, the single heavy-ion
induced transient gate current in MOSFET has been investigated. The transient gate current with both positive and negative
peaks is observed by hitting an ion to gate area, and the amount of collected charge converges on zero within 100ns after
irradiation. The transient current in n-MOSFET is larger and also shorter than p-MOSFET because of mobility difference
between electrons and holes. It is also confirmed that the current peak increases with applied drain voltage during irradiation.
宇宙環境下で半導体デバイスを使用する場合、重イオンなど高速荷電粒子の照射により誘起される電流に起因した、シングルイベント現象が問題となる。能動領域の薄膜化が可能なSOI (Silicon on Insulator) デバイ
スは、埋め込み酸化膜の存在により能動領域が限定されているために高い耐放射線性が予想されているものの、予想を大きく上回る電荷収集が観測されるとの報
告 1) もあり、酸化膜を有する構造における重イオン誘起電流の発生メカニズム解明が非常に重要である。本
研究では、MOS構造の重イオン照射誘起電流の評価により、酸化膜を介した電荷収集機構について検討を行 っ て き た 2) 。 今 回 は p チ ャ ネ ル お よ び n チ ャ ネ ル
MOSFETに対する照射実験を行い、電流発生機構について検討を行った。
Alゲートp-MOSFETおよびn-MOSFET（ゲート酸化膜 厚 dox=40 nm ， ゲ ー ト 長 L=100 µm ， ゲ ー ト 幅
W=300µm）を作製し、日本原子力研究開発機構の重イ
オンマイクロビームシステムを使用して酸素イオン（15MeV）の照射を行った。なお、照射による損傷を軽減し、かつ単一イオンの入射に起因した誘起電流を正確に測定するため、Single Ion Hitシステムを用いて単一イオン照射を実施し、高速オシロスコープにより照射誘起過渡電流を測定した。
図1に、ソース・ドレイン電極を接地した状態で、
MOSFETゲート領域に重イオンを照射した際の、ゲート電極における照射誘起電流および収集電荷量（電流積分値）を示す。なお照射中のゲート印加電圧は、p-,n-MOSFETそれぞれ-10および+10 Vであり、ゲートから電源方向へ流れ出す電流を正方向として表示した。
結果より、照射後1〜2 ns程度に酸化膜印加電界方向の鋭い電流ピークが、その後、反対方向の小さな電流がそれぞれ観測されること、また、収集電荷量は照射後数10nsで0に収束することがわかった。以上の結果より、酸化膜を介した重イオン照射誘起電流は、変位電流 に よ る も の が 支 配 的 で あ る こ と を 確 認 し 。 pMOSFETの場合、照射により基板内で発生した正孔の酸化膜界面での蓄積による酸化膜電界の急速な変化により大きな正方向電流が流れ、これら過剰正孔のドレ
イン・ソースによる収集により初期状態に戻る際に、逆方向電流が発生したものと考えられる。また、 nMOSFETの方が短時間・大振幅の電流ピークとなった。
これは、正孔に比べて電子の移動度が高いことに起因する。
また、照射誘起ゲート電流のドレイン電圧依存性の評価を行った。その結果、pチャネル，nチャネル形共に、電流ピーク値は照射中に印加したドレイン電圧（絶対値）と共に、大きくなることがわかった。ドレ
イン電圧印加時には、ドレイン近傍のゲート酸化膜電界はソース近傍に比べて小さくなる（表面電位が大きくなる）。ただし、重イオンが入射されると、照射により発生した高密度の正孔が内部電界により基板表面に引き寄せられ、チャネル部分全体に蓄積されるため、表面電位は場所によらずほぼ同電位になることが予想される。すなわち、ドレイン近傍の酸化膜電界の変化
速度は、ドレイン電圧と共に大きくなるものと考えられる。以上のメカニズムにより、重イオン照射誘起ゲート電流のドレイン電圧依存性を説明できることがわかった。

Fig.1 Heavy-ion induced gate currents (solidlines) and collected charges (dashed line) in pand n-MOSFET.
References
1) T. Hirao et. al.:“Study of single-event current pulses
induced in SOI diodes by collimated swift heavy-ionsmicro-beams,” Nuclear Instruments and Methods inPhysics Research B 206（2003）457-461.
2) 高橋芳浩 他:“MOS構造における重イオン照射誘起 電 流 ”, 電 子 情 報 通 信 学 会 論 文 誌 , Vol.J89-C,
No.3（2006）pp.104-112.

－ 8 －JAEA-Review 2007-060

1-05 Bias Dependence of the Single Event Transient
Currents due to Nuclear Products in Semiconductors II
a)

a)

a)

S. Onoda , T. Hirao , T. Ohshima , H. Kanekob)and T. Sanamic)a)Environment and Industrial Materials Research Division, QuBS, JAEA,b)
Department of Advanced Radiation Technology, TARRI, JAEA,
c)
Radiation Science Center, KEK

High energy neutrons and protons can trigger Bit Error
Rate (BER) degradation in optical data links used inradiation environments1,2). It is known that thephotodetectors, which are the principle component of
optical receivers, are more prone to BER degradation than
external encoding electronics. Although the direct ionization
results in BER degradation in the photodetectors operated
under low optical power level, it is also possible for thesecondaries generated by nuclear reactions to induce BER
degradation. In silicon based materials, the inelastic as wellas elastic reactions generate high-energy secondaries such as
He, C, N, O, F, Ne, Na, Mg, Al, Si, P, and recoiling Si
atoms with energies up to several tens of MeV. The ionizing
energy loss of these secondaries induces a current on theterminal of the photodetector resulting in a Single Event
Transient (SET) current that contributes to BER
degradation.
In order to clarify the carrier dynamics resulting in the
SET currents in Si pin photodiodes due to neutrons, we havemeasured the SET current induced by energetic heavy ions(C, O, and Si ions) assuming secandaries. Then we haveevaluated the bias dependence of the SET characteristics
such as collected charge, peak current, fall time and risetime, respectively.
The device examined in this work was a commercial 1.5
GHz (at -3 dB) Si pin photodiode with a diameter of 450 μm.
The p-layer width was about 0.2 μm, the depletion width

was about 15 μm at -10 V as estimated by thecapacitance-Voltage (C-V) and cross-sectional Transient Ion
Beam Induced Current (TIBIC) methods. All proton
induced SET currents were measured at various biases from
-5 to -30 V.
Figure 1 (a, b, c) show the bias dependence of thecollected charge, the peak current, the fall time, and the risetime due to C, O, and Si ions with energy up to 15 MeV,
respectively. As shown, the charge increases in proportion
to ion energy for all ions and does not depend on ion energy.
The peak current increases with increasing applied bias
although fall time and rise time decrease. These facts showthat the higher bias leads to the faster drift velocity ofcarriers, which results in the higher peak current and shorter
fall and rise time. On the other hand, the peak current
decreases with increasing atomic number. The mostprobable reason is that the charge screening effect isinfluenced considerably when the atomic number
incresaes3).
References
1) E. Petersen, IEEE NSREC Short Course, section III(1997)
2) S. Onoda et al., JAEA Takasaki annual report 2006
(2007) 9
3) S. Onoda et. al, IEEE Trans. Nucl. Sci., vol. 53, no. 6(2006) 373

6MeV
9MeV
12MeV
15MeV

0.8
0.6
0.4
0.2
0.0

0

5

10

15 20 25
Bias ( V )

30

35

0.4
0.2
1.2
1.0
0.8
0.6
0.4
0.2
4.0
3.2
2.4
1.6
0.8

6MeV
9MeV
12MeV
15MeV

0.8
0.6
0.4
0.2
0.0

(c)
Fall time ( ns ) Peak current ( mA ) Charge ( pC )

0.2

0.6

Rise time ( ns )Fall time ( ns ) Peak current ( mA ) Charge ( pC )

0.4

1.2
1.0
0.8
0.6
0.4
0.2
4.0
3.2
2.4
1.6
0.8

(b)

Rise time ( ns )Rise time ( ns )Fall time ( ns ) Peak current ( mA ) Charge ( pC )

(a)
0.6

0

5

10

15 20 25
Bias ( V )

30

35

0.6
0.4
0.2
1.2
1.0
0.8
0.6
0.4
0.2
4.0
3.2
2.4
1.6
0.8

6MeV
9MeV
12MeV
15MeV

0.8
0.6
0.4
0.2
0.0

0

5

10

15 20 25
Bias ( V )30

35

Fig.1 Bias dependence of the SET current characteristics such as the collected charge, the peak current, the fall time, andthe rise time induced by (a) C, (b) O, and (c) Si ions with energy up to 15 MeV.

－ 9 －

JAEA-Review 2007-060

1-06 Study of Charge Induced in 6H-SiC n+p Diodes
by Gold Ion Incidence
a)

a)

a)

a,b)

c)

T. Ohshima , S. Onoda , S. Hishiki , N. Iwamoto , A. Sakamoto ,c)d)b)
I. Nakano , G. Wagner and K. Kawanoa)Environment and Industrial Materials Research Division, QuBS, JAEA, b)The University ofElectro-Communications, c)Faculty of Science, Okayama University, d) Institute of Crystal Growthsilicon (Si), nickel (Ni) ions were also investigated. In thecase of O and Si ions, the CCE obtained for this diodeshowed more than 95 %. On the other hand, the values of
the CCE for Ni- and Au-irradiated diodes are 86 and 53 %,respectively. The distributions of e-h pairs were calculatedusing the method developed by Kobetch and Katz (KK) 6,7).
As the result, the estimated result indicates that the densityof e-h pairs in Au-irradiated SiC is 100 times higher thanthat in O-irradiated SiC. Therefore, the decrease in the CCE
by Au irradiation obtained in this study can be interpreted interms of the recombination of carriers generated in depletion
layer because the recombination of generated carriers mightoccur in such high dense plasma.
This study was partially supported by the Ministry and
Education, Science, Sports and Culture, Grant-in-Aid for
Scientific Research (B), 2006, 18360458.
0.24
0.20
Collected charge (pC)

Silicon carbide (SiC) is expected to be applied to particle
detectors used in radiation environments since SiC has
superior radiation tolerance1). For this purpose, it isimportant to clarify the behavior of charge generated in SiC
by ion incidence. In a previous study 2), it was reported that
the Charge Collection Efficiency (CCE) obtained from
4H-SiC diodes irradiated with alpha particles was 100 %.
The CCE of 100 % was also reported for 6H-SiC diodes
irradiated with oxygen (O) ions 3). These results suggest that
SiC is suitable for particle detectors. For the development ofparticle detectors, the CCE of SiC diodes should be
evaluated using a wide variety of ions. In this study, weevaluate charge generated in 6H-SiC diodes by 12MeV-gold(Au) ions.
The samples used in this study were 6H-SiC n+p diodes
fabricated on 30 μm thick p-type epitaxial layer with analuminum (Al) concentration of 8x1014 - 1x1015 /cm3. The
epitaxial layer was grown on a p-type substrate (3.5o off,
Si-face) by chemical vapor deposition. The 100nm thick n+region was formed using phosphorus (P) ion implantation (amean P concentration of 5x1019 /cm3) at 800 oC followed byannealing at 1650 oC for 5 min in argon (Ar). Al electrodes
were formed using a liftoff technique. The diodes were
irradiated with 12 MeV-Au microbeams under applied
reverse biases, and transient current generated by irradiationof Au ions was measured using the Transient Ion Beam
Induced Current (TIBIC) system 4).
Figure 1 shows the value of collected charge as a functionof applied reverse bias. The estimated value of charge
generated in the depletion layer (ideal value) is also
represented as a broken line. In the estimation, ionizing
energies deposited from 12 MeV Au ions into SiC were
calculated by Monte Carlo simulation code SRIM2003 5).
The energy for the generation of an e-h pair (Ee-h) in 6H-SiC
is assumed to be 7.8 eV (= 2.8Eg) on the analogy of Ee-h in
Si since the value of the energy for 6H-SiC has not yet been
determined. The collected charge of 0.1 pC is obtained andthe value does not depend on the applied biases. On theother hand, the ideal value is estimated to be 0.195 pC.
Since the depletion layer is estimated to be 5 μm at an
applied bias of 20V and the range of 12 MeV-Au is 1.9μm,
the obtained result indicates that approximately half ofcharge generated in the depletion layer is not collected
despite under the reverse biases.
The CCEs for 6H-SiC diodes irradiated with 12 MeV-O,

0.16
0.12
0.08
Experimental
Ideal

0.04
0.00

0

20

40

60

80

100 120 140 160 180

Applied bias (V)Fig. 1 Value of collected charge obtained for a 6H-SiC
diode by 12 MeV-Au irradiation as a function of applied
reverse bias.
References
1) T. Ohshima et al.: J. Appl. Phys. 96 (2001) 3038.
2) F. Nava et al.: Nucl. Instr. Meth. A 505 (2003) 645.
3) T. Ohshima et al.: Nucl. Instr. Meth. A 541 (2005) 236.
4) J. S. Laird et al.: Nucl. Instr. and Meth. B 181 (2001) 87.
5) J. F. Ziegler, Handbook of Ion Implantation Technology,
Elssevier Science Publishers B.V., The Netherland(1992) pp.1-68.
6) R. Katz et al.: Rad. Eff.and Def. Sol. 114 (1990) 15.
7) E. J. Kobetich, R. Katz: Phy. Rev. 170 (1968) 391－ 10 －

JAEA-Review 2007-060

1-07 EPR Identification of Intrinsic Defects in 4H-SiC:
Positively-charged Carbon Antisite-vacancy Pairs
a)

a)

a)

b)

T. Umeda , N. Mizuochi , J. Isoya , S. Hishiki , N. Morishitab)and T. Ohshimab)a)Graduate School of Library, Information and Media Studies, University of Tsukuba,b)Environment and Industrial Materials Research Division, QuBS, JAEA
In the present work, the positive charge state [CSiVC]+(S=1/2) has been identified in electron-irradiated p-type(B-doped) 4H-SiC (2−10×1018 e/cm2, 800 °C, RT carrier
concentration before irradiation ∼1015 cm-3)4). The EPR
spectra labeled HEI9a/b and HEI10a/b (Fig.2) wererecorded at 295K on a Bruker E500 X-band spectrometer.
In 4H-SiC, both silicon and carbon atoms have two
inequivalent lattice sites, hexagonal (h) and quasi-cubic (k)sites. For each of four spectra, HEI9a/b (C3v) and HEI10a/b(C1h), the 13C (I=1/2, natural abundance 1.1 %) HF tensor
has been determined from the fitting of the angulardependence of the HF lines (See Fig.2 for B//c). The 13C HF
tensors obtained are useful to assign each of four spectra toone of (hh, kk, hk, kh) configurations by comparing with the
HF tensors of four configurations estimated by ab initio
supercell calculations. Here, hh represents the configurationthat both carbon-antisite and carbon-vacancy are h sites. The
unpaired electron strongly localizes on each CSi atom(55-58 %) with a dominant p-character. The angle θ
between the p-orbital direction and the c-axis is 0° for
HEI9a/b and 109° for HEI10a/b. The observed 29Si HF
splittings agree with those obtained by ab initio supercell
calculations4).
Observation of four sets of spectra, which all exhibit
similar dose dependence and thermal behavior (Fig.3) andare assignable to four configurations (hh, kk, hk, kh),
respectively, is a strong basis that HEI9/10 is arising from
[CSiVC]+.
We apply photo-EPR technique which measures the EPR
signal intensity as a function of the wavelength ofilluminating light, to determine the defect level in the bandgap. It has been determined that the electronic level of
CSiVC+ is located at around EV+1.4eV.

To improve the radiation hardness of SiC devices,
identification of radiation-induced defects are required. We
use electron paramagnetic resonance (EPR) technique formicroscopic structural identification of intrinsic defects in
4H-SiC. To track the angular dependence of the 29Si/13C
hyperfine (HF) lines which does lead to decisive structure
determination, it is desirable to produce the intrinsic defectof interest selectively at sufficient concentration. We took asort of defect engineering approach by using various
combinations of the temperature and the dose of 2 MeV
electron irradiation (1×1017−1×1019 e/cm2), the temperature(400−1200 °C) of heat-treatment after irradiation, and
4H-SiC samples (3×10×1.5 mm) of both n- and p-type ofdifferent dopant concentrations.
Carbon antisite-vacancy pair CSiVC, which is one ofnearest neighbor carbon atoms moving into the vacantsilicon site with a carbon vacancy left, corresponds to abistable counterpart of silicon vacancy (Fig.1). The negative
charge state [CSiVC]− which was identified in irradiatedn-type 4H-SiC (2 ×1018 e/cm2, 800 °C) gives the SI5 EPR
spectrum which had been originally observed in HPSI
(high-purity semi-insulating) substrates. Thus, CSiVC is adominant carrier-compensating, intrinsic defect producing
the SI properties. Theoretical studies predicted that thepositive charge state [CSiVC]+ should be much more stable
than silicon vacancy in p-type while [CSiVC]− should be
metastable in n-type2,3).
CSiVC

VSi

References
1) T. Umeda et al., Phys. Rev. Lett., 96, 145501 (2006)
2) M. Bockstedte et al., Phys. Rev. B, 68, 205201 (2003)
3) E. Rauls et al., Phys. Rev. B, 68, 155208 (2003)
4) T. Umeda et al., Phys. Rev. B, 75, 245202 (2007).Fig.1 Bistability of CSiVC and silicon vacancy (VSi)

3

/cm )

5

13

C

9b

29

13

13

C

9a

x10

9a/10a
29

Si

Si
13

13

C

C
x10

10b 10a

9b

x20

4

333

334

335

336

337

(b)
HEI9/10 (CSiVC)

C

13

C

9b

9a

10b 10a

x20

3
2
1
0

332

(a)

17

295K
dark
B // cConcentration (x10

EPR signal (arb.units)

10b

338

339

340

341

342

0 2 4 6 8 1018

Magnetic field (mT)+13

Fig.2 EPR spectra (labeled HEI9/10) of [CSiVC] . The C
and 29Si HF lines of HEI9a/b and HEI10a/b are indicated.

－ 11 －

Dose (x102e/cm )

EI5/6 (VC)

boron
acceptor

P6/7 (VSiVC)

unknown

800

1000

1200
o

Anneal Temperature ( C)

Fig. 3 Dose dependence and anneal-temperaturedependence of the concentrations.

JAEA-Review 2007-060

1-08 Mechanisms of Decrease in Hole Concentration in
Al-doped 4H-SiC by Irradiation of 200 keV Electronsa)b)

H. Matsuura , S. Hishiki , T. Ohshimab)and H. Itohb)a)

Department of Electronic Engineering and Computer Science, Osaka Electro-Communicationb)
University, Environment and Industrial Materials Research Division, QuBS, JAEA

From the temperature dependence of the holeconcentration p(T) in Al-doped 4H-SiC epilayers irradiatedwith 4.6 MeV electrons, we reported that the density (NAl)of a shallow acceptor with Ev + 0.2 eV, which is an Al atom
at a Si sublattice site, was significantly reduced, while thedensity (NDefect) of a deep acceptor with Ev + 0.35 eV wasslightly decreased,1) as shown by triangles of Fig. 1. Here,
Ev is the valence band maximum.
In unirradiatedepilayers,2) on the other hand, NDefect = 0.6 NAl in a range of
NAl between 8x1014 and 5x1016 cm-3, as shown by open
symbols of Fig. 1.
Since electrons with <0.3 MeV can displace only carbon(C) atoms in SiC whereas electrons with >0.5 MeV displace
all the atoms (i.e., C, Al and Si) in SiC,3) we investigate thechanges of NAl and NDefect in a 10 μm-thick Al-doped
4H-SiC epilayer by irradiation of 200 keV electrons. Afterthe Hall-effect measurement was carried out in the epilayer
irradiated with 1x1016 cm-2 fluence, the epilayer was
irradiated with 2x1016 cm-2 fluence. Figure 2 shows p(T)denoted by open circles (unirradiated), solid circles(fluence: 1x1016 cm-2) and solid diamonds (total fluence:
3x1016 cm-2). At low temperatures, p(T) decreases withincreasing fluence, whereas p(T) seems unchanged at highFig.1 Relationship between NAl and NDeep. The open
symbols of squares, circle and triangle are therelationship before irradiation. The solid circle anddiamond represent the relationships after irradiation of
1x1016 and 3x1016 cm-2 with 200 keV electrons,
respectively.
The solid triangle represents therelationship after irradiation of 2.6x1014 cm-2 with 4.6
MeV electrons.

temperatures, indicating that by irradiation of 200 keVelectrons the NAl is decreased while the sum of NAl and
NDefect is unchanged.
From the analysis of p(T), the values of NAl and NDefectwere determined, and are shown as an open circle(unirradiated), a solid circle (fluence: 1x1016 cm-2) and asolid diamond (total fluence: 3x1016 cm-2) of Fig. 1.
Different from the changes of NAl and NDefect by irradiationof 4.6 MeV electrons, NAl decreases with increasing fluenceof 200 keV electrons, while NDefect increases. Moreover,the decrement of NAl is nearly equal to the increment of
NDefect. Therefore, the displacement of only C atoms by
irradiation of 200 keV electrons is considered to change theAl acceptor into the deep acceptor.
The changes of NAl and NDefect by irradiation at more
fluences (5x1016 and 7x1016 cm-2) of 200 keV electrons are
now investigated.
References
1) H. Matsuura et al.: Appl. Phys. Lett. 83 (2003) 4981.
2) H. Matsuura et al.: J. Appl. Phys. 96 (2004) 2708.
3) H. Matsuura et al.: Physica B 376-377 (2006) 342.

Fig.2 Temperature dependence of hole concentration.
The open circles represent p(T) before irradiation, andthe solid circles and diamonds represent p(T) after
irradiation of 1x1016 and 3x1016 cm-2 with 200 keVelectrons, respectively.

－ 12 －

JAEA-Review 2007-060

1-09 First-principles Molecular Dynamics Simulation of
SiO2/SiC Interface of Silicon Carbide Devices
a)

b)

b)

A. Miyashita , T. Ohnuma , M. Iwasawa , H. Tsuchidaa)b)

and M. Yoshikawaa)b)Environment and Industrial Materials Research Division, QuBS, JAEA, Materials Science
Research Laboratory, CRIEPI

Silicon carbide (SiC) semiconductor devices are expected
to be used in severe environments such as outer space andnuclear power plants. The performance of the SiC MOSFET
device is below theoretically expected levels because thedefect in SiO2/SiC interface degrades the electrical performance of the device. The relation among atomic structures,interface defects and electrical characteristics is not clear atpresent. In this study, we tried to solve these problems by
the computer simulation of electronic structure of the
SiO2/SiC interface. It is important to construct anamorphous SiO2 (a-SiO2) structure on SiC to emulate thereal device interface structure by the computer simulation
because the oxide layer of the real device is an amorphous
structure. We aimed to generate a-SiO2/SiC structure withlarge-scale (1000 atoms scale model) calculation to which
the amorphous structure was able to be constructed.
Amorphous SiO2/SiC interface structure is made by
applying the heating and quenching calculation that uses thefirst-principles molecular dynamics code VASP1) (Vienna
ab-initio Simulation Program) to the atomic interface structure model that consists of SiC crystal substrate and crystalline SiO2 thin layers. The heating and quenching calculationof 444 atoms of SiO2/SiC interface structure that had been
done last year used the condition of 3.0 ps heating by 4000
K and the cooling speed of -1000 K/ps. It was confirmedthat the SiO2 layers of the interface structure were almost
amorphous structure.2-3). The atomic density of the interface
structure was obtained in the direction of the perpendicularof the interface. (Fig.1) In the SiO2 layers near the interface,a periodic change of the density that reflects the crystalline
structure was not seen; therefore, these layers are good
amorphous structures. However, the density of the SiO2
layers near the surface shows a periodic density change. It is
guessed that the recrystallization occurred from the surface
in the quenching process because the crystalline structure
remained near the SiO2 surface. It was suggested that thecontinuance annealing is necessary.
The generation of a-SiO2/SiC interface structure was triedby using the large scale model that consisted of 1017 atoms.
P

Fig.1 The atomic density of the 444 atoms of SiO2/SiC interface structure at room temperature.

Fig.2 The temperature condition of the heating and quenching process and the total energy of the interface structure model.
In the large scale model, the following conditions were used
to improve the amorphous structure near the surface. Figure
2 shows the temperature condition of the heating andquenching process and the total energy of the interface
structure model. The SiO2 layer has melted being heated by
2 ps at the temperature of 4000K on the condition of fixing
SiC layers except 2 interfacial layers, surface Si of SiO2
layers and H that terminate surface Si. The interface
structure has been cooled down to the temperature of 3500K.
After the removal of H and release of surface Si, theinterface structure was continuously annealed for 2 ps. Thenthe interface structure was quenched to the room
temperature. It was confirmed that the recrystallization had
not occurred in the quenching process because the periodic
change of density had not been observed after the interface
structure had been quenched to the room temperature. As aresult of the radial pair distribution function (RDF) analysisof the SiO2 layers, the bond length and the bond angle of Si
and O have been obtained. The Si-O bond length, the
Si-O-Si bond angle, and the O-Si-O bond angle of the SiO2
layers are 0.165 nm, 135 deg, and 109 deg, respectively.
There is a small peak about 0.23 nm in partial RDF of Si
and Si. This means the Si-Si bonding actually exists in SiO2
layers as a defect structure. The short range order of thebond length and the bond angle obtained from the result of
the analysis of these partial RDF has suited the condition of
a-SiO2. Therefore, it was confirmed that an excellent
a-SiO2/SiC interface structure was generated by heating andquenching calculation.
References
1) G.Kresse et al., Phys. Rev. B54, (1996) 11169.
2) A.Miyashita et al., Annual Report of the Earth Simulator
Center Apr.2005-Mar.2006, (2006) 287.
3) A.Miyashita et al., Materials Science Forum 556-557,(2007) 521.

－ 13 －

JAEA-Review 2007-060

1-10 Development of Optoelectronic Devices for Radiation
Environments - Optical Gain of Eu Implanted AlGaN a)

a)

a)

a)

a)

A. Wakahara , H. Okada , F. Oikawa , H. Kawai , T. Shimojyo , T. Ohshimab)and S. Sato b)a)

Department of Electrical and Electronic Engineering, Toyohashi University of Technology,b)Environment and Industrial Materials Research Division, QuBS, JAEA

Temperature dependent luminescence and the optical gain of AlGaN doped with Eu ions are investigated fordemonstrating the capability of rare-earth doped light emitting devices for radiation and/or hard environments. The Eu
related photoemission, caused by 4f inner shell transitions, shows excellent thermal stability and even at 400K theluminescence intensity is more than 50% for low temperature (10K) case. Optical gain and loss measurements are carried out
using variable stripe length and shifting excitation spot methods, respectively. The estimated optical gain is as high as 100
cm-1, which is comparable to that reported molecular-beam-epitaxy grown GaN:Eu sample.

Log PL intensity [a.u.]

現在のSi系集積回路技術は、微細加工技術・集積化技術により高度な機能と高速動作を実現してきた。放射線環境下に対しても、SOI技術の導入により問題解決が進められつつある。信号伝達の観点からは、宇宙空間に於いても光通信が有望とされているが、光源として用いられている少数キャリアの再結合による発光
デバイスは放射線損傷の影響を強く受けるため、その寿命、信頼性など解決すべき問題が多い。本プロジェ
クトでは、耐熱性・対放射線に優れ、環境温度の変化により発光波長、発光効率が影響を受けにくい希土類
イオンを発光中心として導入したIII族窒化物半導体を用いて、多数キャリアベースの発光デバイス実現の可能性を検討した。
AlGaN発光層への希土類添加は、原子力機構・高崎
研のイオン注入装置を用いて、加速電圧100～350 keV、
ドーズ量1×1013 cm-2～8×1015 cm-2とし、室温にてEuを注入した。イオン注入後、窒素抜けを防ぐためNH3を含
むN2雰囲気中にて、1100 ℃、2minのアニールを行い注入損傷の回復を図った1)。
Rutherford Back-Scattering(RBS)測定より推定したEuイオンの結晶中での位置は、Euからの散乱はチャ
ネリング条件に於いてもランダム配置の7割程度の散乱強度があり、格子間位置を占めるEuが多数有ること

10-2

References
1) A. Wakahara, Optical Materials, 28 (2006) 731
2) H. Ofuchi et al., Physica B, 376-377 (2006) 496
3) K. L. Shaklee et al., J. Lumin. 7 (1973) 284
4) J. H. Park et al., Appl. Phys. Lett., 85 (2004) 4588

gmod~130 cm-1

10-3
測定条件
Pex= 8mJ (~1MW/cm2)
Al0.3Ga0.7N:Eu
NEu ~ 1020cm-310-4
0を 示 し て い る 。 一 方 、 Extended X-ray Absorption
Fine Spectra(EXAFS)の解析結果からは、EuはGaサイトを占めるとの結果が得られており2)、両者が共存していると思われる。
発光特性の耐温度特性評価は、ArFエキシマレーザ(193 nm、100 J/cm2 ・pulse)を励起光光源として用いたホトルミネセンス法により10Kから400Kの範囲で行った。発光強度の測定温度依存性は極めて小さく、Al組成がx>0.3の試料では、400Kに於いても10Kでの発光強度の50%以上の強度を維持しており、チップ温度が大きく変化する環境下での光デバイスの発光層として十分な安定性を有している。
次に、Eu添加AlGaNの発光デバイスとしての可能性を検証するため、光増幅率および伝搬損失の評価を行った。光増幅率は、Variable Stripe Length(VSL)
法 3) を 用 い て 求 め た 。 伝 搬 損 失 は 、 Shifting
Excitation Spot (SES)法により求めた。Fig.1に測定結果を示す。イオン注入法を用いて、活性層厚が50nm程度と非常に薄いにも係わらず100 cm-1 を越える大きな光増幅率を示し、伝搬損失も10 cm-1以下と十分小さ
く光増幅器およびレーザへの応用が十分可能な特性が得られている。ここで得られた結果は、分子線エピタ
キシャル成長法により作製された高品質なGaN:Euで報告されている値 4) と同程度以上の特性が得られており、
イオン注入法を用いた新しい半導体発光デバイスプロ
セスへの展開が期待される。

0.05
0.1
Excitation Length [cm]Fig.1 Optical gain measurement for Al0.3Ga0.7N:Eu at
300K. The Eu dose was 1×1015 cm-2. The excitation
power density was ~1 MW/cm2.

－ 14 －

JAEA-Review 2007-060

1-11 Gamma Radiation Effects on GaN Based Electron
Devices
a)

a)

a)

a)

H. Kameoka , M. Okada , J. P. Ao , Y. Ohno and T. Hiraob)a)Institute of Technology and Science, The University of Tokushima,
Environment and Industrial Materials Research Division, QuBS, JAEAb)

GaN electronic devices, especially AlGaN/GaN
Heterostrure Field Effect Transistor (HFETs), are expected
for high-frequency and high-power applications due towide-bandgap and III-V semiconductor characteristics 1, 2).
Since the application includes power module andmicrowave power transmission for space solar powersystem, the employment of GaN-based devices in artificial
satellite in space is being considered. The purpose of thisresearch is to investigate the tolerance of these devices
under γ-ray irradiation in space and other harsh environment
3-5).
The sample AlGaN/GaN HFETs were fabricated on(0001) sapphire substrate. It consisted of a buffer layer, a 3µm undoped GaN layer, a 6 nm undoped AlGaN barrier, a
12 nm Si-doped AlGaN layer with doping concentration of
4×1018 cm-3, and a 6 nm undoped AlGaN barrier layer (Fig.
1). The Al mole fraction of all the AlGaN layers was 25 %.
Ohmic contact was formed using lift-off technique withelectron-beam-evaporated Ti/Al/Ni/Au (50/200/40/30 nm).
They were annealed at 850 ºC for 1 minute in N2.
The samples were irradiated with Co sources at JAEA
Takasaki. The total dose of γ-ray was 8.9 Mrad and 86.7
Mrad at the dose rate of 1x106 rad/h. The channel length andwidth of the measured transistor was 4 µm and 50 µm,
respectively.
If the FETs are damaged, variations will appear in thegate leakage current, threshold voltage or carrier drift
mobility. As shown in Fig. 2, each sample has inherently
different gate leakage currents, but they did not change after
the irradiation. Also, the threshold voltages did not change.
Only the difference was the increase of drain current (ID).

NiAu

Converting drain voltage (VD) versus drain current
characteristics into drain voltage versus drain conductance(GD) characteristics, it was found that the variation was only
in low drain voltages and a constant resistance variation
regardless of the gate bias. From these facts, the variation is
attributable to improvement in the ohmic contact by γ-ray
irradiation. The annealing in the fabrication process may
have been insufficient. 6)
Radiation experiments under a DC bias condition weredone on different Metal-Insulator-Semiconductor (MIS)
HFET. The FET has 10nm SiN on AlGaN layer depositedby sputtering. DC bias of -9V was applied to the gateelectrode while the drain terminal was kept open.
After irradiation of γ-ray at 1 Mrad, no particularvariation was observed except for small ohmic contact
improvement similar to the previous experiment (Fig. 3).
Although material and process technologies for
AlGaN/GaN HFETs have not yet been well controlled andthe performance variations exist even without radiation, no
particular degradation was observed even under extremely
high dose irradiation of 87 Mrad.
References
1) Y. F. Wu, et al., IEEE Trans Electron Dev., 48, 586(2001).
2) J. P. Ao, et al., IEEE Electron Dev. Lett., 24, 500 (2003).
3) C. W. Wang, et al., J. Appl. Phys., 88, 6355 (2000).
4) B. Luo, et al., Appl. Phys. Lett., 80, 604 (2002).
5) O. Aktas, et al., Solid-State Electronics, 48, 471 (2004).
6) J.P. Ao, et al., SSDM 2005, pp.478-479, Kobe(2005).

Au
TiAlNiAu

i-GaN

i-AlGaN 6nm
n-AlGaN 12nm
i-AlGaN 6nm
buffer layer

Sapphire sub.

Fig. 1 Schematic crosssection of sample
AlGaN/GaN HFET.

8.9Mrad, before
8.9Mrad, after
86.7Mrad, before
86.7Mrad, afterFig. 2 Gate leakage current before andafter irradiation of γ-rays at 86.7 Mradand 8.9 Mrad. No bias was applied. Drain
to source voltage(Vds) was zero.

－ 15 －

Fig.3 ID-VD and GD-VD characteristicsof the MISHFET, before and after 1
Mrad irradiation under the gate bias of–9V.

JAEA-Review 2007-060

1-12 Study of the Radiation Damages of Practical Used
Semiconductor Devicesa)H. Ohyama , S. Kuboyamab)and T. Hiraoc)a)

Kumamoto National College of Technology
Institute of Aerospace Technology, Japan Aerospace Exploration Agency(JAXA)
c)
Environment and Industrial Materials Research Division, QuBS, JAEAb)

In this report, the impact of radiation damage on thedevice performance of 4H-SiC Metal Semiconductor Field
Effect Transistors (MESFETs) and GaAlAs Light Emitting
Diodes (LEDs) are investigated under different fluence andfluence rate conditions.
4H-SiC MESFETs were fabricated on 4H-SiC
semi-insulating wafers with an epitaxital layer produced by
CREE. The length and width of the gate were 0.5 and100 μm, respectively. GaAlAs-double hetero junction-LEDs(Sharp GL3UR44) with light wavelength 660 nm were also
used in this study.
Electron irradiations into the samples were done at room
temperature using the 2-MV electron accelerator at JAEA,
Takasaki. The used electron fluence ranged from 1 x 1013
to 1 x 1017 e/cm2. Before and after irradiation, the input
drain-source current/Gate-souce voltage characteristics(IDS-VGS) of the SiC-MESFETs and I/V characteristics ofthe GaAlAs LEDs were measured with a parameter analyzer(HP-4156).
To investigate the recovery behavior due to annealing ofradiation damage, isochronal thermal annealing was carriedout for 15 min at temperatures between 100 and 300 oC

0

10

4
3

2-MeV Electrons
15
2
1 x 10 e/cm

-32-MeV electrons162
5 x 10 e/cm

10

-5

C1

Before irra.
1224.68 x 10 e/cm sec
112
4.68 x 10 e/cm sec

10

CURRENT ( A )Normalized Intensity I/Io

References
1)
C. Claeys and E. Simoen,, Springer Verlag, New York(2002).
2)
H. Ohyama et. al., Physica B, 376-377, 382 (2006).
3)
H. Ohyama et. al., to be published in Journal of
Materials Science.

-3(005)peak
5-1

ANNEALING RATE ( sec )6x10

under nitrogen flow without bias.
Figure 1 shows the annealing rate of IDS as a function of
annealing temperature for thy MESFETs irradiated withelectrons at 5x1016 e/cm2. Assuming that the recovery
process is a first order reaction, the activation energy of therecovery is estimated from Fig.1 to be 0.27 eV.
Figure 2 shows the typical results of I/V characteristics
for different electron fluence rates (4.68 x 1011 and 4.68 x
1012 e/cm2sec). Total fluence was selected for 1 x 1015 e/cm2.
From this figure, it is noted that the remarkable degradation
is observed for low dose rate condition than for high rateirradiation. This fluence rate dependence of degradation canbe explained in terms of the heat impact in bulk crystal
during irradiation.

VGS = 1.0 V(Ea = 0.27 eV)

C4

2

-7

10

-9

10

-11

10

○ 0.5MeV C 1
C8
1 ● 2.0MeV C
4□ 4.0MeV C 8
–1
10 0
0
2
4
2.2
2.3 14
2.4
2.5
2.6 2
Fluence (10 carbons/cm)-11000/T ( K )Fig.1
dependence
theasintensityof (005)
for.
Fig.1 Fluence
Annealingrate of ofIDS
a functionof peakannealing
temperature for SiC-MESFETs.

-13

10

-15

10

-3

-2

-1

0

1

VOLTAGE ( V )Fig.2 I/V characteristics of electron-irradiated GaAlAs
LEDs at different fluence rates.
.

－ 16 －

JAEA-Review 2007-060

1-13 Radiation Resistance of Insulating Material for ITER
Superconducting Coil -Gas Evolutiona)

b)

a)

a)

b)

A. Idesaki , N. Koizumi , M. Gokan , N. Morishita , M. Sugimoto ,a)b)
T. Ohshima and K. Okunoa)Environment and Industrial Materials Research Division, QuBS, JAEAb)
ITER Project Unit, FRDD, JAEA

Table 1 The components of epoxy resin used in this work.
Samplewas in an order of 10-9mol/g. Therefore, the gas evolution
from the laminated materials shown in the Fig. 1 is
attributed by decomposition of the epoxy resin. Comparing
the sample A with the sample B, the amount of the evolved
gases from the sample A containing cyanate ester was about
60 % less than that from sample B containing TGDDM.
This suggests that the insulating material for thesuperconducting coil with low gas evolution can beobtained by using the cyanate ester as a raw material for
epoxy resin.
Reference
1) A. Idesaki, et al., Advances in Cryogenic Engineering,Vol. 52(2006)pp.330-334.

Evolved gas (10-6mol/g)

40Components of epoxy resinA

DGEBF + Cyanate EsterB

DGEBF + TGDDM

H2
CO
CO2
Total

30

10

0

TGDDM :N,N,N’,N’-tetraglycidyl-4,4’-diaminophenylmethane

5

10

120

15 20 25
Dose (MGy)

H2
CO
CO2
Total

100
80

30

35

Sample B

60
40
20
0

DGEBF : Diglycidyl ether of bispehnol F

Sample A

20

0

Evolved gas (10-6mol/g)

A laminated material composed of glass cloth /polyimide film / epoxy resin will be used as an electricalinsulating material in the superconducting coil of theInternational Thermonuclear Experimental Reactor (ITER).
This material is fabricated by impregnation of epoxy resin
into a glass cloth / polyimide film prepreg and subsequentcuring. Therefore, the viscosity and pot-life (time to curethe resin) of the epoxy raw material are very important for
the fabrication of the insulating material. In addition,
sufficient mechanical and electrical properties are required.
Moreover, the insulating material must show high radiation
resistance and thermal resistance, because it will be
exposed to severe environments such as high radiation field
and low temperature of 4K.
In this work, the gas evolution from laminated materials
by gamma ray irradiation at 77K was investigated, and thedifference of gas evolution behavior due to difference ofcomponents in the epoxy resin was discussed.
Two kinds of the laminated materials with different
components of epoxy resin were investigated (Table 1).
Each sample was put into a glass tube, and the glass tube
was evacuated and sealed. The samples were irradiated by
gamma rays up to dose of 30 MGy as maximum at a dose
rate of 37.5 kGy/h at 77K, and then the gas analysis was
conducted by a gas chromatograph at room temperature
after storage of the samples at room temperature for 16
hours.
Figure 1 shows the evolved gases from the laminatedmaterials by the irradiation of gamma rays at 77K. The total
amount of evolved gas increased almost linearly withincreasing in the dose. Main components of the evolved
gases were hydrogen (H2), carbon monoxide (CO) andcarbon dioxide (CO2). Hydrocarbon gases such as methane(CH4) were evolved as minor components with an order of
10-8-10-7 mol/g. We have investigated the gas evolution
from a polyimide film by the irradiation of gamma rays at
77K1). It was found that the total amount of evolved gases

0

5

10

15 20 25
Dose (MGy)30

35

Fig.1 The evolved gases from the laminated materials by
the irradiation of gamma rays at 77K. The
measurements were conducted at room temperature
after storage at room temperature for 16 hours.

－ 17 －

JAEA-Review 2007-060

1-14 Gamma-ray Irradiation Test of
Instrumentation and Operational Amplifier
for Remote Maintenance System of ITER
a)

a)

a)

a)

a)

N. Takeda , S. Kakudate , N. Oyake , M. Nakahira , K. Shibanuma ,
b)
b)
b)
c)
c)
c)
A. Idesaki , M. Gokan , N. Morishita , S. Baba , H. Okamoto and T. Hirosea)b)

ITER Project Unit, FRDD, JAEA, Environment and Industrial Materials Research Division, QuBS,c)
JAEA, Ryoei Technica Corp.

Components in the vacuum vessel of the ITER, an
experimental fusion reactor to be constructed underinternational cooperation from this year, must be replaced
remotely for maintenance because neutrons created by D-T
fusion reactions activate structural materials. The radiation
environment during the maintenance operation is about 0.5
kGy/h and therefore, the total dose is 1 MGy if themaintenance operation takes three months. The irradiation
test has been performed for the components of the ITER
remote maintenance system1, 2) and the present report
describes the irradiation test of the instrumentation andoperational amplifiers for strain gauges in order to examine
which amplifier on the market can be used from theviewpoint of radiation-hardness. The tested amplifiers
include the rad-hard products whose guaranteed acceptable
dose is about 1 kGy.
Table 1 shows the list of tested instrumentation andoperational amplifiers. Bipolar amplifiers were mainly
selected because they are expected as rad-hard fromtheoretical point of view. The dose rate in the irradiation
test was almost the same value as that in the realenvironment of the ITER maintenance operation, 0.5 kGy/h.
The amplifiers were irradiated for a certain period with bias
current and after that they were took out from the cell forthe measurement of their electrical characteristics such as
input bias current, offset voltage, gain and so on. This
cycle of irradiation and measurement was repeated.
First, a preliminary irradiation test was performed withthe total dose of 20 kGy for screening. As a result, threekinds of amplifiers (AD524CD, HA1-5104-2 andHS1-5104ARH-Q) still operated normally although some ofcharacteristics were slightly out of specification.
Regarding other amplifiers, AD623BR and LT1078CN8

malfunctioned at 0.25 kGy. One of rad-hard amplifiers,
RH1078MH, had functioned until 2 kGy, which is higher
than the guaranteed value of 1 kGy, with some ofcharacteristics
deviatingfromspecification
andmalfunctioned at 9 kGy.
Next, the irradiation test was performed until 417 kGy forthe three amplifiers which functioned in the preliminary test.
The instrumentation amplifier, AD524CD, had functioned
until 56 kGy with some of characteristics deviating from
specification, and malfunctioned at 169 kGy. The normal
operational amplifier, HA-5104-2, had functioned until 169
kGy with some of characteristics deviating from
specification, and malfunctioned at 417 kGy. The rad-hardoperational amplifier, HS1-5104ARH-Q, had functioned
without deviation of characteristics from specification until
the guaranteed value, 1kGy, and had continued to function
from 2 kGy till 417 kGy with some of characteristics
deviating from specification. Figure 1 shows the transitionof the open loop gain of HS1-5104ARH-Q during
irradiation.
The broken and dotted lines show thereference sample and specification, respectively. The gain
showed the minimum value around 10 kGy, recovered afterthat and decreased again from 169 kGy. The deviationfrom specification is generally limited and therefore, thisamplifier can be used until 0.4 MGy exceeding theguaranteed value, 1 kGy.
The normal operational
amplifier can be also used if it is replaced enough frequently.
Regarding HS1-5104ARH-Q, its acceptable total dose will
be investigated in the future study.
References
1) K. Obara et al., JAERI-Tech 99-003 (1999).
2) K. Obara et al., J. Robot. Mechatron. Vol. 10, No. 2(1998) pp. 121-132.

Table 1 List of tested amplifiers

AD623BRAD524CD
HA1-5104-2
HS1-5104ARH-Q
LT1078CN8RH1078MH

ProviderAnalogDevices
AnalogDevicesIntersilIntersilLinearTechnology
LinearTechnology

Type

Guaranteed
Radiation
hardness

Instr.

No

Instr.

No

Op.
Op.

No
1 kGy

Op.

No

1000

Reference
5538
5539

Avol+[kV/V]

Name

5540
Spec

100

10
0.01

0.1

1

10

100

1000

dose[kGy(Si)]

Op.

1 kGy

Fig. 1 Open loop gain of HS1-5104ARH-Q－ 18 －

JAEA-Review 2007-060

1-15 Development of Radiation Resistant O-ringfor Vacuum Use
a)

a)

b)

c)

T. Ogitsu , N. Kimura , A. Idesaki , J. Kusano and T. Tabasaki
a)

d)

b)

KEK, High Energy Accelerator Research Organization, Quantum Beam Science Directoratec)d)(QuBA), JAEA, J-PARC Center, JAEA, Hayakawa Rubber Co. Ltd.

A superconducting magnet system is required for J-PARC
Neutrino beam line to bent the 50 GeV 750 kW proton beam.
The magnet system consists of about 150 m long vacuum
vessel system to provide the thermal isolation for thesuperconducting magnet. The vacuum vessel system
requires a lot of o-rings, of which size can be as large as 1 m
diameter. Conventional o-rings, which uses the materials
like fluoroelastomer (FKM), do not have sufficientresistance against radiation for long term use. High radiation
resistant o-rings, such as metal o-rings, have demerits incosts or handling. Similar problems exist at the expansion
joint sealants of the J-PARC accelerator tunnels. JAEA and
Hayakawa Rubber Co. Ltd. jointly develop the new sealants
based on the ethylene propylene diene monomer (EPDM)
rubber. The new o-ring that can resist the irradiation up to
1 MGy has been developed jointly by KEK, JAEA, andHayakawa Rubber Co. Ltd. based on the EPDM similar tothat used for the expansion joint sealant. This reportsummarizes the irradiation tests performed for this o-ringmaterial.
The samples were irradiated with γ ray at the Cobalt-60
irradiation facility in Takasaki Advanced Radiation
Research Institute, JAEA. The irradiations were made up to
5 MGy at room temperature with air environment. The
mechanical tests based on the Japanese Industrial Standard(JIS) were performed for the samples. The mechanical tests
include measurements of hardness (JIS-K6253), tensilestress (JIS-K6251), and compression set (JIS-K6262). The

ＣＳ / ％

measurement was made for the samples irradiated to 0, 1,
and 3 MGy. The out gas measurements of the samples werealso made for the samples irradiated to 0 and 1.25 MGy.
The measurement results of the compression set are
shown in Fig. 1. The FKM sample was destroyed after
1 MGy irradiation and no data was available. All the EPDM
samples show good results not only in compression set but
also all the mechanical measurements, indicating that the
EPDM can be used as o-rings up to 1 MGy irradiation.
The results of the out gas measurement are shown in Fig.2.
The results indicate that one of the EPDM sample (517)shows a good performance. We selected the sample 517 as
the final candidate from the measurement results shown
here as well as the good processability. The final products
use the same EPDM as 517 but with small modification of
final process. The EPDM was renamed to 517LT, and were
tested for both mechanical and out gas measurements. The
mechanical measurements results show better performance
than those of 517. The out gas measurement results were notas good as the one for 517, but still acceptable from therequirement.
The o-rings are now in the stage of mass production andwill be installed in the magnet system. The magnet system
will be completed in the end of 2008 and operated in 2009.
Reference
1) S. Nakatsukasa et. al., Journal of the Society of Rubber
Industry, Japan Vol.79 (2006) pp 11-16

Compression Set Measurement

10-4

JIS K6262

30

No５０９
Ｎｏ５１１
Ｎｏ５１３
Ｎｏ５１７

20

10-5
Pressure (Torr)

25

15
10

10-6

EPDM O-ring vs FKM O-ring(measurement in 2006)
Confirmation for final product(measurement in 2007)

S513_B2
BaseVT_B2
S517_B
P-513
P-509
P-517
Glasstube
517LT_NI
517LT_1M
517Blank1M
517Blank_NI
517LT_NI2
517LT_1M2

Filled Symbols are with 1.25 MGy irradiation

10-7

5

Blank Symbols are without irradiation

0
0

1

2

3

4
Dose / MGy

5

Fig.1 JIS-K6262 Compression set measurement results.
No.509 is the FKM sample, which destroyed at 1 MGy
irradiation. The other samples are EPDM based.

10-8
0:00:00

System B.G. Pressure (1.98x10

-8

Torr)

20:00:00
40:00:00
60:00:00
Time (h) (after vacuum pumping start)

80:00:00

Fig.2 Out gas measurement results, BaseVT and theP-509 are the FKM, the others are EPDM. The
material chosen for the final products is 517LT.

－ 19 －

JAEA-Review 2007-060

1-16 Measurement of Electrical Property Change in Commercially
Available Coaxial Cable by Gamma-ray Irradiation
a)

a)

b)

c)

J. Kusano , O. Takeda , N. Morishita , K. Takano , S. Ukona)c)and F. Suzukic)b)

Accelerator Division, J-PARC, JAEA, Environment and Industrial Materials Research Division, QuBS,c)
JAEA, Engineering Department, Industrial & Telecommunication Cable Division, Fujikura Ltd.

Introduction
Coaxial cable is an essential element for a communication
tool in a precise measurement system because of stablecharacteristic impedance and electrical noise proof
performance. The J-PARC1), a research facility complex withhigh-intensity proton accelerators, apply a plenty amount ofcoaxial cables to make good telecommunications regarding to
the proton beam circumstance, the accelerator status, RF
signal control and the safety issues. The proton beam power of
the J-PARC is up to 1 MW on the target, which introduces thehigh radiation area along the proton beam line and close to thetarget region caused by undesirable beam loss of theaccelerators. We measured the electrical property change inthe commercially available coaxial cable under the high dose
rate gamma-ray irradiation to confirm the reliability of thecontrol and the data acquisition tool of the J-PARC.
Measurement
A pair of 40 m long coaxial cables (Fujikura NH-8D-SFA)
was prepared as a race-track shape to compare the difference
between a fresh cable and an irradiated cable. The irradiatedcable is 3MGy pre-dosed by gamma-ray. Both cables are tied
up and installed in the cell facing the Co-60 gamma-ray
source on even dose condition, and the characteristics aremeasured alternatively. The dose rate of the gamma-ray is
chosen 6.3 kGy/h to simulate the high radiation spot in the
J-PARC. The measured items are insulation resistance, RF
attenuation, phase shift, time delay, charge up andcharacteristic impedance.

Fig.1 Coaxial cable irradiation and measurement set up.
Fresh cable and 3 MGy pre-dose cable were bind up withcontact and examined alternatively in same dose
condition.
Result1) No gamma-ray run as static characteristics
Slightly degradation, range of a few percent, was observedfor RF attenuation, phase shift, time delay and characteristic
impedance on the 3 MGy pre-dose cable caused by increasing
capacitance and dielectric constant shift at the insulator

material. The insulation resistance between the innerconductor and the outer conductor decreased in the pre-dose
cable by 20 % of the fresh one. The absolute value of theresistance still remains at the normal use level.
2) High gamma-dose run as dynamic characteristics
In the high radiation condition, the property of the pre-dose
cable shows a constant deterioration for phase shift, time delay
and characteristic impedance by several percent. The RF
attenuation was -40 dB/km at GHz band. The charge up
phenomenon was observed both the fresh cable and thepre-dose cable. Potential difference between the innerconductor and the outer conductor was measured during the
gamma-ray irradiation period. The charge up voltage fluctuatedthrough the beginning to the several minutes after theirradiation period2). These phenomena affect like a common
mode noise to the control and the beam monitoring system of
the J-PARC.

Fig.2 Insulation resistance between the inner and outerconductor behavior around 10 minutes exposure.

Fig.3 Potential difference behavior between the conductors
and ground potential induced by charge up around the 10
minutes exposure. IC denotes the inner conductor andOC denotes the outer conductor in the figure caption.
References
1) S. Nagamiya, Proc. International Radiation Shielding(ICRS-9), J. Nucl. Sci&Technol., Supplement 40 (2000)
2) Y. Tanaka et. al., Proc. Annual Rep. CEIDP (1998) 629－ 20 －

JAEA-Review 2007-060

1-17 Research on Radiation Resistance of Grease, etc.
for Reprocessing Cell Equipment
a)

a)

a)

a)

a)

N. Okamura , H. Ogino , Y. Arai , T. Kase , T. Koizumi ,
b)
b)
b)
c)
A. Idesaki , N. Morishita , T. Oshima and T. Kojimaa)b)

Nuclear Cycle Engineering Department, NFCEL, JAEA, Environment and Industrial Materialsc)Research Division, QuBS, JAEA, Department of Advanced Radiation Technology, TARRI, JAEA
After these experiments, the rate of base oil, the nitricacid concentrations and the fragment concentration in grease
were measured. These measured values were not different
from ones in the cold endurance experiment. These results
showed that the driving units by using these greases had
abilities to be operated continuously and no additive
damages to ball bearings and greases was caused by
combining mechanical load, nitric acid and radiation.
Furthermore the differential thermal analysis was adopted
to evaluate grease degradation. Previously, the gelpermeation chromatography and the infrared spectroscopy
were used for the evaluations, which requested all of grease
left in the ball bearing after the operation. This new method
had some advantages, such as a small amount of sample anda simple pretreatment. The results of measurements areshown in figure 2. It was found that the variation of GK-1
was larger than that of RG-42R-1 in molecular weight. The
reason why is as follows: the base oil of GK-1 consisted of
not di-alkyl tetraphenyl but tri-alkyl tetraphenyl mainly, sothat it was oxidized easily by radiation. The GR-42R-1 wasmore suitable than the GK-1 under the reprocessing cellatmosphere.
References
1) T. Washiya et al., Proc. GLOBAL2005 (2005)
2) M. Takeuchi et al., Proc. ICONE13 (2003)

Motor
Rotor

Driving Unit

100
Mass residue (%)

In the nuclear cycle engineering department of JAEA, aninnovative centrifugal contactor system has been developed
for an advanced aqueous reprocessing of FBR fuel 1). The
centrifugal contactor would be one of the key equipments toestablish better reprocessing economy because of its
compact size and rapid processing performance. It was
already confirmed that it had a higher extraction capacity
through the uranium test 2). Furthermore, in a cold
experiment, the driving unit with ball bearing and grease
had been operated continuously for 5000 hours that was
equal to a term of an annual operation in the reprocessing
plant. In this study, the equipment was operated undergamma-ray irradiation, and the durability of the driving unit
was confirmed under the simulated reprocessing plant
atmosphere with mechanical load, nitric acid and radiation.
The schematic diagram of experimental equipment isshown in figure 1. Generally, the extraction process consistsof several centrifugal contactors, but this was one stage witha liquid self-circulation system because of the restriction of
Co-60 gamma-ray irradiation facility. Two kinds of greases,
RG-42R-1 and GK-1, were chosen from the viewpoint ofradiation and heat resistance. The significant difference
between them was that GK-1 contained MoS2 as a solid
lubricant to extend the lifetime. In a series of irradiation
experiments, 900mL of nitric acid and 400mL of
n-dodecane with the TBP concentration of 30% were poured
into it. The exposure rate (72C/kg/h) in this irradiation
facility was about ten times higher than that in the
reprocessing cell, so the irradiation time was set 500 hours.

90
80

Grease:RG-42R-1

70

untreated
No irradiation
500h
Irradiated for 500hr
1000h

60

Organic phase collector

Aqueous phase collector
50

50

100

150

200

250

300

350

300

350

Temperature (℃)

Organic
circulation pipe

Mixingarea

Mass residue (%)

100

Aqueouscirculation pipe

90
80
70

Grease:GK-1
No irradiation
untreated
Irradiated for 500hr
500h

60
50

Fig.1 Schematic diagram of experimental centrifugal
contactor－ 21 －

50

100

150

200

250

Temperature(℃)

Fig.2 TG-curve measured with differential thermal
analysis

JAEA-Review 2007-060

1-18 Investigation of Effect of Radiation Deterioration
on Confinement Capability of Glove-box
H. Abe, K. Watanabe, S. Tashiro and G. Uchiyama
Nuclear Facility Safety Research Unit, NSRC, JAEA
In the mixed-oxide (MOX) fuel fabrication facility, MOX
is required to be handled in Glove-box to sustain
containment of MOX into the facility.
Since theGlove-box consists in some inflammable components suchas plastic panel and packing, in case of fire in the facility,
the static containment capability of the Glove-box may be
deteriorated by pyrolysis or combustion of the components
by thermal stress. Deterioration of the static confinement
capability of the Glove-box may cause release of MOX to
the room involving the Glove-box and to the outside of the
facility and exposure of worker and public around thefacility. Therefore, to confirm the safety of the facility
under the fire, acquisition of fundamental data of thethermal properties of the components and establishment of
quantitative evaluation method of time-course of thedeterioration are very important. From this point of view,in JAEA, the thermal properties of the components havebeen investigated as a contract research from Japan Nuclear
Energy Safety Organization (JNES)1). The purpose of thisresearch is to examine exothermic and endothermic
properties, such as starting temperatures, calorific values,
temperature ranges and reaction rate data of the relative
reactions of the components, as the pyrolysis properties bythermal analysis. Moreover, energy and mass release rates
as source-term data for thermo-fluid analysis in the
Glove-box and ventilation system and smoke generation rate
as source-term data for clogging analysis of the ventilation
filters with combustion of the inflammable components of
the Glove-box have been also examined by using“Apparatus for Evaluation of Source-term under Fire
Accident”.
Since a large amount of MOX is handled in the MOX fuelfabrication process in the actual facility, the components of
the Glove-box are irradiated by radiation from MOX andReference
1) H. Abe et al., JAEA-Research 2006-054 (2006.9). [InJapanese]

TGA
%

DTA
mW

TGA
%

100

20

100

5
40
0
20

Heat flux(non-irradiation)

30

-5
-10

0
0

100

200

300
Temp [ﾟC]

Temperature

400

500

weight (non-irradiation)

600

20

Heat flux(non-irradiation)40

weight(irradiation)

0
200

400

600
Temp [ﾟC]

Temperature

Fig.1 Experiment results of pyrolysis properties for PMMA

－ 22 －

10

0

20

0

(℃)

(mW)

Heat flux(irradiation)

60

Heat flux

10

60

DTA
mW

80

Weight (%)

weight(irradiation)

15

(mW)

weight (non-irradiation)
Heat flux(irradiation)

Heat flux

80

Weight (%)

radiation deterioration of the components could be caused.
In this contract research, investigation of effect of theradiation deterioration on the pyrolysis properties of thecomponents has been started from fiscal 2006. In the firstplace, to verify the effect, the some components of the
Glove-box were irradiated under an extremely high-dose
condition, 880 kGy (=10 kGy/h×88 h), by using 6th 60Co
cell at JAEA Takasaki.
After the irradiation, theexothermic and endothermic properties and weight change
as a function of temperature of the components were
measuredby
using
Simultaneous
Differential
Thermogravimetric Analyzer (Shimazu DTG-60H).
Figure 1 and Fig.2 show the experiment results about theeffect of the radiation deterioration on the pyrolysis
properties under air atmosphere condition for
Polymethylmethacrylate (PMMA) and Polycarbonate (PC)as commonly used as plastic panel of the Glove-box.
Initial weights of PMMA and PC were about 6 mg and 3 mg,
respectively. Starting temperature of weight decrease of
the irradiated PMMA was shifted to lower temperature than
the non-irradiated PMMA. Moreover, endothermic peak at
about 270 ℃ of the irradiated PMMA decreased than the
non-irradiated PMMA and exothermic peak at about 350 ℃
appeared for the irradiated PMMA. These results mean thepyrolysis rate of the irradiated PMMA is probably fasterthan the non-irradiated PMMA. On the other hand, for PC,
the effect of the radiation deterioration on the pyrolysis
properties was not observed. In future, the more detailed
investigation, for example, observation of threshold of dose
affecting the pyrolysis properties, is planned.

-10
800

1000

(℃)

Fig.2 Experiment results of pyrolysis properties for PC

JAEA-Review 2007-060

1-19 Corrosion Behavior of Type 316L Stainless SteelIon-irradiated under Deformed Condition
a)

a)

a)

a)

K. Kondo , Y. Miwa , N. Okubo , Y. Kaji and T. Tsukadaa)a)Division of Fuels and Materials Engineering, NSED, JAEA

Normalized Charge, Pa (C/cm2)

Irradiation assisted stress corrosion cracking (IASCC) on
austenitic stainless steel (SS) is one of the problem inreactor cores. Degradation of materials under irradiation andapplied stress are important to the IASCC initiation1). The
objective of this work is to obtain the fundamental
knowledge on the synergistic effect of residual stress andirradiation on the corrosion behavior of type 316L SS. In
this paper, the correlation between the corrosion behavior
and microchemistry change in irradiated specimens is
discussed from a viewpoint of the effect of residual stress.
In order to examine the effects of residual stress during
irradiation on corrosion behavior, flat plate specimens thatwere plastically deformed by bending constraint and without
deformation constraint were irradiated by 12 MeV Ni3+ ion
using the tandem accelerator and a vacuum chamber at
JAEA- Takasaki. Plastic strain of the irradiation surface
region in bent specimens was calculated to be about 2%.
Irradiation temperature was 330 ºC. The displacement
damage levels ranged from 1 to 45 dpa. The corrosion
behavior of irradiated specimens was estimated by means of
single-loop electrochemical potentiokinetic reactivation(SL-EPR) testing, in which the corrosion property wasevaluated using the normalized charge (Pa). And, three
dimensional atom probe (3D-AP) analysis was conducted on
the irradiated specimens to investigate the microchemicalcompositional change in irradiated specimens.
The dose dependence of the values of normalized charge(Pa) is shown in Fig.1. The Pa of undeformed specimen
increased rapidly with increasing dose, and saturated above
12 dpa. In case of the deformed specimens, on the other
hand, the Pa below 12 dpa was much smaller than that of the
undeformed specimen. At 6 dpa irradiation, the Pa for the
deformed specimen was 0.01 C/cm2, which was about 2
orders of magnitude lower than the value for the
undeformed specimen, 5.7 C/cm2. At 45 dpa irradiation, thePa was almost the same between the deformed specimen andthe undeformed specimen.
Since the significant effect of residual stress on corrosion
behavior was observed in the specimens irradiated to 6 dpa,
microchemical composition measurement was conductedusing the 3DAP. Fig.2 shows Si atom map in the deformed
specimen. Inhomogeneous distribution of Si was observed.
In the Si enriched region, enrichment of Ni and depletion of
Cr were observed. Chemical composition was measured inseven segregation regions. The enrichment of Si
composition was 4.7±0.8 at.%, and the depletion of Cr
composition was 4.5±1.4 at.% in comparison with the bulk
composition. In the undeformed specimen, inhomogeneous
distribution solute was also observed and the segregation
behavior was similar to that in the deformed specimen.
Chemical composition was measured in four segregation
regions. The depletion of Cr composition was 5.2±1.5 at.%,and enrichment of Si composition was 6.6±2.0 at.%. It was,therefore, speculated that the degree of Cr depletion and Si
enrichment at a sink such as dislocation was greater in
undeformed specimen than in deformed specimen. And, it
could be suggested that radiation induced segregation
behavior of solute atoms as a consequence of diffusion andannihilation of irradiation defects at sink is affected byresidual stress.
The corrosion behavior of SSs was related to the diffusion
behavior of the solute atoms such as Cr. It could be
speclated that, due to the suppression of the segregation ofsolute by residual stress, deformed specimens showed
higher corrosion resistance than undeformed specimens.
Reference
1) K. Kondo et al., Proc. of 13th Int. Conf. Env. Degradationof Materials in Nuclear Power Systems – Water Reactors,
2007, to be published.

100
10

20 nm
1

Fig.2 Three dimensional map of Si atoms in 316L
irradiated at 330°C under the deformed condition. The
volume is approximately 15 x 15 x 170 nm3.

SUS316L 330℃ irrad
Deformed
Undeformed

0.1
0.01
1E-3
0

10

20

30

40

50

Displacement Damage (dpa)

Fig.1 Dose dependence of corrosion behavior in single-loop
EPR testing on deformed and undeformed specimens.

Present study is the result of “New evaluation method ofmaterial degradation considering synergetic effects ofradiation damage” entrusted to Japan Atomic Energy
Agency by the Ministry of Education, Culture, Sports,
Science and Technology of Japan (MEXT).

－ 23 －

JAEA-Review 2007-060

1-20 Mechanical Properties of Austenitic Stainless SteelIon-irradiated under External Stress
a)

a)

b)

a)

a)

I. Ioka , Y. Ishijima , M. Futakawa , H. Ogawa , Y. Nakahara and T.Naoec)a)Division of Fuels and Materials Engineering, NSED, JAEA,b)c)
QuBS, JAEA, Graduate School of Ibaraki University

Table1 Chemical composition of 25Cr-35Ni-0.2Ti (wt%)
Fe
bal.
O
0.0011

Cr
24.55
S
0.0009Ni
34.99
Si<0.005

Ti
0.18
Mn
0.001

C
0.0013P
0.001

N0.0014

The thickness of specimen is about 0.5 mm. It has threedifferent cross-sections (S division:1.5 mm, M division: 1.75
mm, L division:2.0 mm in width) in order to irradiate under
different stress at the same time. The surface of specimen
was polished with #2400 paper.
The specimens were irradiated in triple (12 MeV Ni3+,
1.1 MeV He+ and 380 keV H+) ion beam mode at atemperature of 300 oC using the triple ion beam facility(TIARA). The temperature of the specimen was measured
by an infrared thermometer (THERMAL VISION, NikonCo.). The displacement damage in the specimen was mainly
attributed to Ni3+ ion irradiation. The peak dose was about
10dpa around 2 µm. The He+ and H+ ions were implanted in
depth ranges from 1.0 to 1.5 µm using aluminum foil energy
degraders. The concentrations of He+ and H+ ions in theimplanted range were 15 appmHe and 100 appmH,
respectively, which correspond to LWR condition. The dose
was about 5 dpa in the implanted range of He+ and H+ ions.
Two specimens were irradiated. One was a stressed
specimen. The other was a stress-free specimen which wasprestressed at the same stress level of the stressed specimen.
The microindentation test was carried out on the surfaceof specimens at room temperature. A testing machine,
DUH-200 (Shimadzu Co.), was used for the
microindentation test. A load was applied with a loading
speed of 4.4 mN/s, held 1 second and then removed. Duringloading, the load was continuously monitored along with thedisplacement with a resolution of 2 mN and 0.01μm,
respectively. The Berkovich indenter was used in the
microindentation test. The obtained data were converted into
the relationship between load/depth and depth (L/D-D curve),
and the universal hardness was calculated from these data.
Figure 1 shows the universal hardness of irradiated region
at the S, M and L divisions. The vertical axis denotes theuniversal hardness normalized by the unirradiated ones. The
result of stress-free specimen is added to Fig.1. The

2
Normalized unversal hardness

Irradiation creep has been studied extensively to provide
data that can be used for component analysis of fusion, fast
breeder and light water reactors. It is now generally
recognized that the irradiation creep data were in agreementwith an empirical equation1). Moreover, there have been
many irradiation experiments done under external stress toinvestigate stress effects on microstructural evolution. It isreported that the total nucleation rate of Frank loops wasincreased with increasing external stress2). However, there
are few studies on the effect of external stress on mechanicalproperties of the material under irradiation. The purpose ofthis study is to evaluate the mechanical properties of theirradiated material under external stress.
The material tested is a high chromium austenitic stainlesssteel (25Cr-35Ni-0.2Ti EHP)3) which is a candidate materialof cladding tube for LWR of ultra high burnup. Chemicalcomposition of the specimen is shown in Table 1.
25Cr-35Ni-0.2Ti was machined from the plate produced by
the thermo-mechanical treatment so-called SAR (strained,
aged and recrystallized).

1.5
1
0.5
0
L div.

M div.

S div.

Stressfree

Fig.1 Comparison of normalized universal hardness after
universal hardness of the irradiated specimen was about
40-60 % higher than those of the unirradiated specimen. The
irradiated specimen was hardened by irradiation and external
stress. It is considered that there is little influence of external
stress on universal hardness of the irradiated specimen inthis test condition.
References
1) F.A.Garner et al,, J. Nucl. Mater. 251(1997)252.
2) H.Tanigawa et al., Nucl. Instru. and Methods in Phy.
Resea. B 102(1995)151.
3) K.Kiuchi et al,, ICAPP, June 9-13, 2002(Florida).

－ 24 －

JAEA-Review 2007-060

1-21 Evaluation of Property Change in Ultra High Purity
Austenitic Stainless Steel under BWR Condition
Simulated by Triple Ion Irradiation
Y. Ishijima , I. Ioka , M. Yamamoto and J. Suzuki
Division of Fuels and Material Engineering, NSED, JAEA
1． Introduction
To prevent material degradation under corrosion and
LWR condition, we developed ultra high purity (UHP)
grade (C + N + O < 100 wppm) and high Cr (~25wt% Cr)
austenitic stainless steel. We have evaluated corrosion
behavior and change of mechanical properties of UHP grade
austenitic stainless steel. Decrease of carbon concentrationin stainless steel decreases receptivity of irradiation assisted
stress corrosion cracking (IASCC). As a result, it isconsidered that segregation of small amount (~10 wppm) of
B and P under BWR condition causes degradation of grainboundary corrosion resistance. However, the behavior ofthese elements under BWR condition is not clear. The
purpose of this study is to obtain basic knowledge of
behavior of small amount of impurities (B and P) underirradiation.
In this paper, triple ion irradiation that simulates BWR
condition was carried out for the candidate (Fe- 25Cr- 35Ni0.2Ti UHP grade) and segregation of small amount ofelements around grain boundary was evaluated.

Segregation of elements around grain boundary after
ion-irradiation was evaluated using Auger electron
spectroscopy (AES) in which the electron beam diameterwas 25 nm. After electropolish to a depth of 1.2 μm at
irradiated face, evaluation of segregation was carried out at
10 nm intervals from grain boundary.
3． Results
Figure 1 shows chemical compositions of the candidatearound grain boundary after ion-irradiation by AES
measurement.
From this result, irradiation induced
segregation of Cr was observed but segregation of small
amounts of impurities (B and P) were not observed by AES
measurement.
At next step, 3D-AP measurement will be used toevaluate irradiation behavior and presence state of small
amount of impurities.
50

Grain Boundary

2． Experimental procedures
The candidate (Fe-25Cr-35Ni-0.2Ti UHP grade) was cut
to a size of 6x3x2 mm3. Irradiated area was thenmechanically and electrochemically polished to a specular
finish. Triple ion irradiation simulating BWR neutron
irradiation condition was performed using Ni3+ (12 MeV),
He+ (1.1 MeV) and H+ (0.38 MeV) ion beams. Aluminum
film degraders were used to spread He+ and H+ irradiatedarea. Irradiation temperature was 573 K. Irradiation
damage and ion-implantation depth were calculated using
TRIM code. As a result, He+ and H+ ion-implantation
depth was estimated to be 1.1~1.3 μm and irradiation
damage of this area to be 75 dpa. He+ and H+ concentrations
in ion-implantation area were 3 and 30 appm/dpa,
respectively.

－ 25 －

Concentration (wt%)

40

Fe
Ni

30

Cr
20

10

B, S, PTi
0

0.1

Measurement distance (μm)

Fig. 1 result of AES measurement

0.15

JAEA-Review 2007-060

1-22 Radiation Hardening of Ferrite Phase in a Dual
Phase Austenitic Steela)

S. Jitsukawa , N. Okuboa)a)and M Andob)b)

NSED, FRDD, JAEA

Dual phase stainless steel is widely used as the structural
material for LWR core component. For example, caststainless steel for LWR components CF8 with similar
chemical composition to that of 304 stainless steel often
exhibits dual phase microstructure depending on the castcondition. During the initial stage of the solidification, .Ni
rich austenite phase is formed. This is followed by ferrite
phase formation with lower Ni content. Although the Ni
content is lower, this ferrite phase containing 2 to 6 % of Ni
is expected to exhibit large hardening by neutron irradiation.
Also, austenite phase containing lower level of Ni has lower
phase stability tends to cause lower toughness after
irradiation. Hardening is often accompanied by the
reduction of toughness and increase in DBTT. Therefore,
susceptibility to irradiation hardening of dual phase stainlesssteel is examined by ion irradiation method at temperaturesfrom 200 oC to 350 oC to damage levels to 5 dpa.
An alloy with nominal chemical compositions of around
0.01C-1Si-0.7Mn-9Ni-19Cr containing 10% ferrite phase
after solution annealing at 1050 oC is used. Yield stress,
ultimate tensile stress and hardness at room temperature are
210 MPa, 490 MPa and 168 Hv (correspond to 2.1 GPa of
average contact area pressure), respectively. Ultra
micro-hardness value was about 4.5 GPa. Surface of thespecimen for ion irradiation was finished byelectro-polishing technique. Irradiation was carried out with
10MeV Fe ions to nominal damage levels of 0.1, 1 and 5
dpa at temperatures of 200, 280 and 350 oC. Hardness after
irradiation was examined with ultra micro-hardness testingmachine with indentation load of 1 g.
Hardness at twenty points was measured for one
specimen after irradiation. Minimum distance between each(a)point was about 10 micro-meter. Size of each indentation
was about 1 micro-meter. Figure 1 (a) shows impressions on
the irradiated surface with microstructure. Dark and lightareas correspond to ferrite and austenite phases, respectively.
Hardness was plotted in Fig. 1 (b). The hardness of theferrite phase (red) was apparently higher than those inaustenite regions, as shown in the figure. Damage level
dependence of the hardness is plotted in figure 2. Plots for a
reduced activation ferritc steel of F82H (a reference alloy)
are also shown in the figure. Before irradiation, hardness forthe dual phase alloy and F82H exhibited similar hardness ofabout 4.5 GPa. After irradiation to 0.1 dpa, some of theferrite phase in the dual phase alloy hardened to 5.5 GPa,
while small hardness change was obtained for austenite
phase and F82H. At higher damage levels, hardness in mostof the ferrite phase was continuously higher than austenite
phase, and attained to 8 GPa at 5 dpa. Damage level
dependence at 280 oC and 350 oC was qualitatively similar
to that at 200 oC. Results clearly indicate that ferrite phasein the dual phase austenitic alloy is susceptible to irradiationinduced hardening.
Acknowledgement
Some of the results are obtained from the researchsponsored by JNES.
References1)M. Ando, et. Al., J. Nucl. Mater, 307-311(2002)260
2)For example; S.Jitsukawa, et. Al., J. Nucl. Mater,
307-311(2002)179 and G.R.Odette, Philos Mag.
85-4(2005)779

20μm

Impressions

Hardness (GPa)

9
7
5

(b)
3

5.5

Before irradiation
10.5

Fig. 1 Microstructure (a) and Hardness (b) after irradiationin the dual phase alloy after irradiation.

Fig. 2 Damage level dependence of hardness in the dual
phase alloy. Results for F82H (a reference martensitic
steel) were also shown.

－ 26 －

JAEA-Review 2007-060

1-23 Study on Irradiation Defect Generation Process andRadiation Induced Segregation in Fe-P Model Alloys
a)

a)

b)

T. Tobita , Y. Chimi , N. Ishikawa , S. Nakagawa
a)c)and A. Iwasec)b)

Reactor Safety Research Unit, NSRC, JAEA, Advanced Science Research Center, JAEA,
c)
Department of Materials Science, Osaka Prefecture University
amount of decrease is in inverse proportion to P content.
And furthermore, both the amount of decreasing ofelectrical resistivity change decreasing induced by electron
irradiation and thermal aging were almost the same. Itmeans that detection of P segregation by electricalresistivity is impossible, or P segregation was not clearlyenhanced in this electron fluence. If the decreasing ofelectrical resistivity change was mainly caused bydecreasing of thermal vacancy introduced by heat treatment,
P may obstruct the migration and annihilation of thermal
vacancies.
Table 1 Chemical composition of materials (wt%)
Material
Fe-0.04wt%PFe-0.1wt%P

Fe
Bal.
Bal.
Mn
<0.01
<0.01

P
0.039
0.103
S
0.00080.0009CSi<0.0005 <0.002<0.0005 <0.002
Cu
O
<0.01
0.019
<0.01
0.018

Fixture (Copper)
Specimen
Heater for
Temp.
control

2MeV
Electron
Dose rate：
1.5×10-9 dpa/s

Thermo-couplet 0.3mmFig.1 Schematic illustration of electron irradiation.
Time, sec
0

5000

10000

15000

5.0E-100.0E+00Δρ, Ωm @77K

To investigate the fundamentals of irradiation
embrittlement mechanisms of Reactor Pressure Vessel steel(RPVs), we have performed electron irradiation experiments
using Fe-based model alloys, such as pure Fe, Fe-Cu and
Fe-P. The impurities in RPVs materials have been known tohave a storing effect on the irradiation embrittlement. The
Cu precipitates which grow during irradiation cause
irradiation hardening, while the P segregation to the grainboundary weakens the Fe-Fe bonds. Our previous study 1)
shows the changes of electrical resistivity of Fe-Cu model
alloys induced by electron irradiations at high temperature
to evaluate the irradiation damage mechanisms, such as the
behaviours of irradiation defect and Cu clustering in thematerials.
In this paper, we measured the changes of electricalresistivity of several types of Fe-P model alloys induced by
2MeV electron irradiations at high temperature (523 K) toevaluate the irradiation damage mechanisms, such as the
behaviours of irradiation defect and P segregation to thegrain boundary in the materials. We tried to obtain the dose
dependence and P content dependence of the electricalresistivity change.
The chemical composition of these materials is shown in
Table 1. The Fe-P model alloys were fabricated as pure as
possible to eliminate the effects of impurities. After the heat
treatment at 950 °C for 10 min, the materials were quenchedto keep the P atoms in supersaturated solid solution at room
temperature. The specimens were cut into ribbons of 1mm
width, 0.03 mm thickness, and the four electrodes were
spot-welded. Figure 1 shows the schematic illustration ofelectron irradiation apparatus. 2 MeV electron irradiation
was performed at dose rate 1.5x10-9 dpa/s. The electricalresistivity was measured at 77K in LN2. In addition to these
irradiation tests, thermal aging experiments at the same
temperature were performed to clarify the irradiation
temperature effect.
Figure 2 shows the electron dose dependence and thermal
aging time dependence of the electrical resistivity change in
Fe-0.1 %P and Fe-0.04 %P, where thermal aging time andelectron irradiation time were almost the same. At thistemperature and dose, accumulation of irradiation defects(vacancy and interstitial) is negligible 1) . Therefore, thedecreasing of electrical resistivity change was mainly
caused by behavior of P or annihilation of thermal vacancy
introduced by heat treatment.
The electrical resistivity change decreases with increasing
electron dose and aging time in all materials. However, the-5.0E-10●Fe-0.1%P@Electron irrad.
○@Thermal aging▲Fe-0.04%P@Electron irrad.
△@Thermal aging-1.0E-09-1.5E-09-2.0E-09-2.5E-09
0.0E+00 2.0E-06 4.0E-06 6.0E-06 8.0E-06 1.0E-05 1.2E-05

Dose, dpa

Fig.2 Electron dose dependence and thermal aging timedependence of the electrical resistivity change in Fe-0.1 %P
and Fe-0.04 %P.
Reference
1) T. Tobita, Y. Chimi, N. Ishikawa, S. Nakagawa and A.
Iwase, JAEA-Review 2006-042 (2007)20.

－ 27 －

JAEA-Review 2007-060

1-24 Evaluation of Radiation Damage Created via
Elastic Displacements in Oxide Ceramics
N. Ishikawa
Division of Fuels and Materials Engineering, NSED, JAEA
10MeV Ni →CeO2 (HT–irradiation ）Intensity (arb. units)(002)peak

32

33

34

2θ (degree)
Fig.1 Evolution of X-ray diffraction peak assigned for (002)reflection of CeO2 irradiated with 10 MeV Ni at hightemperature (400 ℃). The fluence ranges from 0 (top)to 1.0x1016 ions/cm2 (bottom).

0.6

10MeV Ni →CeO2● RT–irrad

Δa/ao (％）

Radiation damage is one of the important causes ofdegradation of thermal conductivity and serious swelling in
MOX (Mixed Oxide) fuel. Understanding of radiation
damage in nuclear fuel is important for controlling fuelproperties during burn up and for the prediction of fuel burnup behavior. The objectives of this study are to elucidate theirradiation parameter dominating the radiation damage of
ceramics by means of accelerator experiments, and to
precisely evaluate their radiation damages. Especially for
simulating the process of radiation damage by elastic
displacements, 10MeV Ni irradiation experiment has been
performed at room temperature and at high temperature, andCeO2 target which has the same crystal structure with
nuclear fuel is adopted.
Thin films of CeO2 were prepared on Al2O3 single crystal
substrates, and were irradiated with 10 MeV Ni ions at room
temperature and at high temperature of 400 ℃. After theirradiations, fluence dependence of change of X-ray
diffraction pattern was measured in the wide fluence rangeof 1012-1016 ions/cm2, in order to quantify thecorresponding radiation damage. The film thickness was
restricted to be about 0.3 μｍ which is thin enough to ruleout the possibility of unrequired implantation effects.
In Fig.1 evolution of X-ray diffraction peak for different
fluence is shown for CeO2 irradiated with 10 MeV Ni at
400 ℃. It is found that the intensity of the peakmonotonically decreases as increasing fluence, but in thehigh fluence region this tendency slows down. This reflectsthat the sample maintains its crystal structure even in thehigh fluence region, and the CeO2 structure has highradiation resistance up to 1016 ions/cm2. It is also found thatthe peak position shows complex fluence dependence; itmoves toward high angle side in the low fluence region(<1013 ions/cm2), and moves back to low angle side in thehigh fluence region (>1013 ions/cm2). This tendency isclearly demonstrated in Fig.2, where lattice parameterchange decreases in the low fluence region and increases in
the high fluence region. The increment of the lattice
parameter for room temperature irradiation is more
prominent than that for high temperature irradiation whencompared at high fluence region (1015-1016 ions/cm2),
suggesting that the created oxygen defects are diminishedby thermal energy in case of high temperature irradiation.
Present study is the result of “Research of highly accurate
evaluation of radiation damage in advanced nuclear reactor
fuel ceramics” entrusted to “Japan Atomic Energy Agency”
by the Ministry of Education, Culture, Sports, Science andTechnology of Japan (MEXT).

0.4 ○ HT–irrad
0.2
0

–0.2

10

12

10

14

2

Fluence (ions/cm )10

16

Fig.2 Fluence dependence of lattice parameter change
normalized by that of unirradiated sample in CeO2
irradiated with 10 MeV Ni at room temperature (RT:closed circles) and high temperature (HT: open circles).

－ 28 －

JAEA-Review 2007-060

1-25 Behavior of Advanced Materials under Heavy Irradiation
a)

a)

a)

a)

a)

a)

N. Okubo , E. Wakai , S. Yamashita , M. Ando , S. Otsuka , S. Jitsukawa ,b)b)
N. Hashimoto and S. Ohnukia)Nuclear Science and Engineering Directorate, JAEAb)
Hokkaido University
800

ΔYield Stress (MPa)In the structural materials heavily irradiated in fusion
reactor, next generation fast breeder reactor and IFMIF
target etc., displacement damage and He accumulation
simultaneously occur by high energy irradiation. The
materials are degraded by the effect of superposition.
Therefore, to understand dependences of behaviors ofirradiation hardening and microstructural evolution on
displacement damage and He concentration is important formodeling of irradiation behavior.
In this study, the behavior of irradiation hardening of the
reduced activation ferritic steels F82H was evaluated in thehigh damage region. For oxide-dispersion-strengthened(ODS) martensitic steel, which was one of the candidate
materials for fuel cladding used in the next generation fast
breeder reactor, the microstructural evolution was
conducted under irradiation.
Ion irradiation of 15 MeV-Ni４+ to the F82H (IEA Heat)
was conducted at 270℃ in order to investigate theirradiation-hardening behavior up to 165 dpa. The change ofthe micro-hardness (ΔH) measured by nanoindentation wastransformed to that of yield stress (Δσy) by relation of ΔH≒ 3 Δσy１）The microstructual evaluation was conducted byin-situ TEM observation under 200 keV He ion irradiation
at room temperature and 550℃ for 9Cr martensitic and
12Cr ferritic ODS steels.
Dependence of irradiation hardening on the displacement
damage on the F82H is shown in Fig. 1. The irradiation
hardening increased gradually as increasing the damage up
to 20 dpa. The slope appeared to be shelving around 40dpa
and subsequently saturating. The value of power obtained
from the log-log plots of Δσy vs. dpa data was about 0.12
for the high dpa regime.
The vicinity of oxyde particles in 12Cr ODS steels
observed by in-situ TEM under He irradiation (7 appm-He)
is shown in Fig. 2. The He bubble formation around theboundary between oxide particle and ferrite matrix was
observed as the fluence of He ions was increased. In 9Cr
ODS steels, however, the bubble formation was notobserved under irradiation.

F82H

400

0
0

100

200

Damage (dpa)
Fig.1 Dependence of irradiation
displacement damage in F82H

hardeningon

30nm
Fig.2 Vicinity of oxide particles of 12Cr ODS steels
Reference
1) J.T. Buswell, C.A. English, M. G. Hetherington, W.J.
Phythian, G.D.W. Smith,G.N. Worral, Effect ofradiation on materials, The 14th
International
Symposium (Vol II), N. H. Packan, R.E. Stroller, A.S.
Kumar, Eds., ASTM STP-1046, American Society for
Testing and Materials, Philadelphia, (1990)127-153.

－ 29 －

JAEA-Review 2007-060

1-27 Polymer Electrolyte Membranes for Fuel Cell
Applications Prepared by Ion Track Technology
T. Yamaki, A. Hiroki, S. Hasegawa, H. Koshikawa, M. Asano, Y. Maekawa and M. Yoshida
Environment and Industrial Materials Research Division, QuBS, JAEA
Accordingly, it was confirmed that the membrane had acylindrical electrolyte part with a diameter of about 100 nm,
comparable to the size of the etched pore. In other words,
we were able to prepare a novel PEM, which possessednano-sized proton-conductive pathways extending along theion projectile as was expected.
Figure 2 shows a plot of water uptake, defined as:
100×(Ww－Wd)/Wd, where Ww and Wd are the membraneweights in the wet and dry states, respectively, as a functionof the ion exchange capacity. In all cases, the water uptakeof the nano-structure controlled membranes was enhancedwith an increase in the ionic content. A notable result wasapparent from the comparison with the properties of not
only a Nafion membrane, but also the PEMs separately
obtained by the usual γ-ray-induced homogeneous grafting(result not shown). The water uptake was lower than that of
the homogeneously-grafted membranes in spite of the sameion exchange capacity; for example, it decreased from 36%
to 23% (up to about two-thirds) at 1.6 meq/g. An inert
PVDF host without any graft electrolyte chains was found to
restrict the swelling of the entire membrane. It can beconcluded, therefore, that our PEM is applicable for use in a
PEFC, thus extending the performance beyond the limit ofconventional ones.
References
1) T. Yamaki et al., JAEA Takasaki Annual Report 2005
(JAEA-Review 2006-042) (2007) 35.
2) T. Yamaki et al., ECS Transactions 3 (2006) 103.
3) T. Yamaki et al., Electrochemistry 75 (2007) 175.
4) T. Yamaki et al., GSI Scientific Report 2004 (2005) 260.
80
70

Water uptake (%)

Proton exchange membranes (PEMs) for polymer
electrolyte fuel cells (PEFCs) have recently been developedby our original swift-heavy-ion based technique in addition
to the γ-ray or electron-beam crosslinking and graftpolymerization. The bombardment of high-energy ionsproduces cylindrical damage along with their trajectory inpolymers. Our main focus is the use of such a localized
damage area that is called a latent track. The approach using
this ion track technology is being taken according to twotechniques. One is the track etching and subsequentchemical modification inside the etched pores1-3); and theother is ion-track grafting4), i.e., direct grafting into theactivated zone. The report in the preceding issue1) described
the former attempt including the preparation methodology
and proton conductivity of the resulting membranes. We
present here, as an extension of this study, their other basic
characteristics as a PEM.
The commercial fluoropolymer films were employed asa matrix for maintaining a reasonable mechanical andchemical stability. A 25-μm-thick poly(vinylidene fluoride)(PVDF) film was bombarded by 3.5 MeV/n 129Xe from the
TIARA cyclotron at the JAEA. According to the establishedprocedure, track etching was then performed in a 9 M KOH
aqueous solution at 80˚C. The pore density ranged between
3.0×106 and 3.0×109 /cm2, which agreed with the number ofactually irradiated ions per 1 cm2. The sulfonic acid groups
were introduced into the track-etched cylindrical pores of
100 μm diameter via the γ-ray-induced styrene grafting andsubsequent sulfonation1-3).
A transmission electron microscope (TEM) was used toobserve the morphology of proton-conductive, hydrophilic
domains in the membranes. Figure 1 is the representative
TEM micrograph of a cross section of the membrane stainedby ruthenium tetraoxide (RuO4) vapor. This revealed thatthe stained lines with about a 100 nm width were arranged
almost parallel to the through-thickness direction.

60
50
40
30
20
10
0

Fig. 1 Cross sectional TEM image of the RuO4-stained
membrane. The white two-headed arrow indicates the
direction perpendicular to the membrane surface, i.e., thethickness direction.

0

0.5

1.0

1.5

2.0

2.5

3.0

Ion exchange capacity (meq/g)

Fig. 2 A plot of water uptake versus the ion exchange
capacity of the membrane (filled circle). For comparison,
the result of Nafion117 is also plotted (open circle).

－ 31 －

JAEA-Review 2007-060

1-28 Hybrid Polymer Electrolyte Membranes Prepared by
Radiation Grafting and Silane-crosslinking Techniques
J. Chen, M. Asano, Y. Maekawa and M. Yoshida
Environment and Industrial Materials Research Division, QuBS, JAEA
Hybrid polymer electrolyte membranes (PEM) havebeen widely studied for the application in intermediate
temperature fuel cells1-5). These membranes are generally
prepared by incorporating inorganic particles into organic
polymer electrolytes. The inorganic particles enhance thewater retention and thermal stability of PEMs. However,
because of the lack of covalent bonds between the twocomponents, the inorganic particles are easily separated out
from the organic PEM.

In this work, we attempted to combine the radiation
grafting and silane-crosslinking to prepare a covalently
crosslinked hybrid PEMs1). For this purpose, we grafted a
specialaromatic
vinylsilane
monomer,namelyp-styryltrimethoxysilane (StSi), which has aromatic rings
available for sulfonation and has trimethoxysilyl groups
available for silane-crosslinking, into poly(ethylene-cotetrafluoroethylene) (ETFE) base film. The StSi-grafted
ETFE film was sulfonated in chlorosulfonic acid solution
and then silane-crosslinked by hydrolysis and condensationin HCl solution.

Figure 1 shows the structures of the monomer and the

prepared new hybrid PEMs. The proton conductivity as afunction of temperature is shown in Figure 2. The proton
conductivity of the hybrid PEM linearly increased withincrease in temperature, while for Nafion, the proton
conductivity gradually increased with temperature up to
70°C, and then quickly increased in the temperature risefrom 80 to 100 °C. The drastic increase in conductivity of
Nafion was due to the changes in its structure. Therefore,
Nafion is not appropriate for application in a fuel cell
operating at temperatures above 80 °C. On the contrary, inthe new hybrid PEMs, no drastic increase in proton
conductivity was found over the tested temperature range,
indicating the stable microstructure of this membrane and its
suitability for use in higher temperature fuel cells.

As seen in Figure 3, the thermal stability of the new
hybrid PEMs exhibited a degradation temperature near
318°C, which was about 50 °C higher than that of thestyrene-based membrane (268 °C), and was comparable to
Nafion (320 °C). This enhanced thermal stability was due tothe temperature tolerance of the crosslinked silicon networkin the membrane. In addition, the silicon attached to thep-site aromatic rings enhanced the electronic density andthus increased the bond stability between aromatic rings andsulfonic acid groups. Furthermore, due to thesilane-crosslinking structure introduced, the new hybrid
membrane showed the high chemical stability than that ofthe divinylbenzene-crosslinked styrene-grafted PEMs.
References
1) J. Chen et al, J. Membr. Sci. 296 (2007) 77.
2) J. Chen et al, J. Membr. Sci. 277 (2006) 249.
3) J. Chen et al, J. Membr. Sci. 269 (2006) 194.
4) J. Chen et al, J. Power Sources, 158 (2006) 69.

－ 32 －

JAEA-Review 2007-060

2-01 Utilization of Scallop Processing Waste with Graft
Adsorbent
a)

a)

b)

H. Nakai , T. Temma , M. Tamada ,
c)
c)
c)
d)
T. Sawamura ,T. Saito , T. Honma and K. Satoa)Hachinohe Technical Laboratory, Aomori Industrial Research Center,
Environment and Industrial Materials Research Division, QuBS, JAEA,
c)
Hachinohe National College of Technology, d) Kawasaki Plant Systems, Ltd.
b)

Experimental equipment was assembled for removal of Cd 2+ in mid-gut gland with the iminodiacetic acid adsorbents
synthesized with radiation-induced graft polymerization. To check some effectiveness of the experimental equipment.
The spatial distribution of the Cd 2+ concentration in mid-gut gland in the basket and the removal rate of Cd 2+ withregenerated adsorbents were investigated. As a result, a few variation in the Cd 2+ concentrations of mid-gut gland wasfound in the basket. No significant difference of the adsorption performance was observed between regenerated
adsorbents and fresh ones. These results indicate that our equipment is suitable for the purpose.
とを示している。
以上のように、中腸腺からのCd2+除去、捕集材の再生特性を調べた結果、スケールアップによる阻害要因は無く、予想通りの結果を得ることができた。
【謝辞】本研究は独立行政法人新エネルギー・産業技術総合開発機構（NEDO）の産業技術研究助成事業により実施したことを記し，感謝の意を表します。
200mm

100mm
100mm
100mm
100mm

200mm

1.0

2.0

0.6

1.5

1.0

0.8

1.8

1.5

0.3

1.5

2.3

1.1

1.7
2.3

1.2

1.1

1.6

0.6

Fig.1 Spatial distribution of the Cd2+ concentration in
mid-gut gland in the basket （ after 24 hour ）（concentration of Cd2+：mg/kg）

2+

Concentration
of2+
Cdin mid-gut
in mid-gutgland
gland
Concentrationof Cd（m g（mg/kg/ k g））

ホタテ貝の加工にともない廃棄されている中腸腺を肥料や飼料等の資源として有効利用することを目的とし，Cd2+を除去するための中腸腺処理装置を開発した。
この装置では、中腸腺からリンゴ酸溶液でCd2+を溶出させるとともに、放射線グラフト重合法により作製した捕集材を通して溶液を循環させ、Cd2+を効率良く捕集することができる。
中腸腺処理装置を用いて、中腸腺 30 kgを 0.1 Mリン
ゴ酸溶液 150 L（固液比 0.2）で処理した。リンゴ酸溶液を 30 ℃に保ち、中腸腺を入れたカゴの下方からバブ
リングを行なった。捕集カラムは直径 100 mm、厚さ約0.8 mmのイミノ二酢酸型グラフト重合捕集材 800 枚を充填したもの１基を使用した。リンゴ酸溶液は 3 L/min（空間速度SV＝36 h-1）の速度で循環させた。時間ごとにカゴの上面の中腸腺、溶出槽中の溶液、Cd2+捕集カ
ラムの通液直後の溶液を採取し、含有するCd2+濃度をICP分析装置で測定した。24 時間後については、処理のバラツキを調べるため、Fig.1 に示したカゴの 18 箇所から中腸腺を採取し、Cd2+残濃度を調べた。
次に使用した捕集カラムは再生装置を用いて塩酸で処理を行ない、同じようにCd2+の除去実験を行った。
捕集カラムの再生については、0.6 N塩酸を 1.7 L/min（SV=20 h-1）で捕集カラムに通液させた後、水道水で十分に洗浄した。再生したカラムを使用して前述と同様のCd2+除去実験を行った。
カゴの場所における 24 時間後の中腸腺中のCd2+濃度のバラツキは平均 1.3 mg/kgで、最大で 2.3 mg/kg、最小で 0.6mg/kgであった。リンゴ酸溶液の撹拌効果が高い
カゴ上面及び下面の中腸腺のCd2+濃度が低く、カゴ内部及び外周で中腸腺が重なり合っている所のものは濃度が高かった。中腸腺処理装置のスケールではバラツ
キが大きくなると懸念されたが、バブリングにより溶液が撹拌されたためバラツキを少なくすることが出来た。
再生したカラムを使用してCd2+除去実験を行った結果をFig.2 に示した。中腸腺中のCd2+濃度は新品の時とほぼ同じ結果が得られた。溶出槽中の溶液、Cd2+捕集
カラムの通液直後の溶液についても、新品の時とほぼ同じ結果であった。捕集材の再生が正常に行われたこ－ 35 －

30
25◆Fresh adsorbent

20□Regenerated adsorbent
15
10
5
0
0

6

12

18

Time（ｈ）

Fig.2 Change in the concentration of Cd2+ in
mid-gut gland treated with fresh or regenerated
graft adsorbents

24

JAEA-Review 2007-060

2-02 Study on Analysis of Toxic Elements in Food with Graft
Adsorbent
a)

a)

a)

K. Saito , A. Ogasawara , J. Ichita , N. Sekoa)b)

and M. Tamadab)b)

Hirosaki Technical Laboratory, Aomori Industrial Research Center, Environment andIndustrial Materials Research Division, QuBS, JAEA

The demand for the analysis of toxic elements in food has increased because of the current problem of polluted food. To
analyze toxic elements in food, the thiol-type adsorbent was developed in the present study. The adsorbent was prepared byradiation-induced graft polymerization of glycidyl methacrylate onto polyethylene fiber in aqueous medium and subsequently
the modification with L-cystein in which active sites were blocked by zinc. When the thiol-type adsorbent was put in thecadmium solution of 10ppm, the total amount of adsorbed cadmium reached to 3.4 g/kg-adsorbent. This adsorbent is
considered to have promising properties for cadmium removal.
近年、食品の有害化学物質による汚染が世界的規模で問題となったため、これまであまり問題とされなかった鉛、カドミウム、スズ、ヒ素、水銀等の有害元素の分析の要望が増えている。食品は不均質で、糖、蛋白質、脂質などの金属分析に対して妨害する成分が多い
ので、分析に際しては煩雑な前処理工程が不可欠であり、これが分析の迅速化や自動化の妨げとなっていた。
そこで我々は、金属吸着時の選択性の高い放射線グラ
フト重合捕集材を食品分析における金属の分離及び定量へと応用し、食品中の金属分析の迅速化や自動化に関する検討を行ってきた。これまでの検討で、食品中の塩濃度の上昇に伴って、特にカドミウム吸着の収率低下が見られたため、より選択性の高い官能基を有する捕集材を必要としていた。
そこで本研究では、生体内において有害金属の解毒をしているメタロチオネインが、チオール基でカドミウ
ム等を捕捉している点に着目し、新規チオール型捕集材の合成を検討した。
チオール型捕集材は、将来、食品中の有害元素除去
素材にも使用するため、安全性を考慮して、チオール基を有するアミノ酸であるL-システイン（L-Cys）を官能基に用い、これとグリシジルメタクリレート（GMA）
母材とを結合させる合成方法を検討した。その際、a)
GMAとL-Cysとをチオール基以外の官能基で結合させる
方法、b) チオール型キレート樹脂は、使用直前にジス
ルフィド結合を還元処理してチオール基に戻して使用するが、これを還元処理なしで使用できる状態を保つ
方法、の両方を満たす方法を検討した。その結果、亜鉛とL-Cysとは、中性、アルカリ性においてチオール基で結合すること１）、また、チオール基と亜鉛との反応性は、食品に多く含まれているナトリウム、カリウム、
カルシウム、マグネシウム等よりは選択性が高く、カ
ドミウム、鉛等と比べると選択性が低い。そのため、容易に亜鉛とカドミウムの交換反応が起こること２）から、先に亜鉛とL-Cysとをアルカリ条件下で反応させてチオール基を亜鉛で塞ぎ、これとGMA母材とを反応させる、以下の合成方法を開発した。
ポリエチレン製不織布に対して、窒素雰囲気下で 10
kGy の電子線を照射した後、グリシジルメタクリレート（GMA）及び Tween20 を純水と混合させて得られるエマ
ルジョン溶液に入れて 40 ℃でグラフト重合を行い、GMA 母材を得た。
次に、メタノール 50 ml に粒状水酸化ナトリウムを添加して 1～10 %溶液に調製した後、酢酸亜鉛 0.22 gと L-Cys 塩酸塩 0.35g とを入れて加熱溶解し、これにGMA 母材１枚（約 0.1 g）を投入して、60 ℃で 24 時間反応させた。反応後、蒸留水で水洗した後、真空乾燥機で乾燥させて、目的のチオール型捕集材を得た。
反応したL-Cys量の指標として、チオール基の硫黄に着目し、波長分散型蛍光X線分析装置（WDX）により測定した結果、Fig.1 に示すように、水酸化ナトリウム濃度が 2 ％付近にピークを示し、最高で 19 μg/cm2の硫黄濃度を示した。
このチオール型捕集材 0.1 g と、10 mg/ℓのカドミウ
ム水溶液 50 ml とを 100 ml バイアル瓶に入れて密栓し、25 ℃の恒温水槽中で 24 時間良く振り混ぜた後、ICP-AES によって溶液中のカドミウムの減少量を測定し、捕集量を求めた。その結果、3.4 g-Cd/kg-ad という結果が得られ、新規チオール型捕集材が、設計通りにカドミウムを捕集していることが確認できた。
References
1) Akira Sato et.al., J.Fac.Appl.Biol.Sci., Hiroshima Univ.,
23 (1984) 1
2) 鈴木和夫他，微量金属の生体作用，季刊化学総説，
27(1995)153－ 36 －

Fig.1 Effect of NaOH concentration inmodification reaction on sulfur
concentration in graft adsorbent.

JAEA-Review 2007-060

2-03 Development of Low-loss Millimeter-wave Devices Using
Fluororesin
N. Ito

a, c)

a)

a)

a)

b)

, A. Mase , Y. Kogi , N. Tateishi , N. Seko , M. Tamadab)and E. Sakatac)a)Art, Science and Technology Center for Cooperative Research, Kyushu University,b)c)Quantum Beam Science Directorate, JAEA, Kyushu Hitachi Maxell, Limited

The development of high performance millimeter-wave
planar antennas is essential for their application to satellite
communications and imaging diagnostics which havebecome increasingly important. For fabricating such devices
by using fluororesin as an antenna substrate, we propose
two methods, i.e., (1) surface treatment of fluororesin
substrate to increase the peel strength of copper foil, and (2)fabrication method using electro fine forming (EF2)technology.
Polytetrafluoroethylene (PTFE) films were irradiated withelectron beam, and different degrees of grafting wereachieved by immersing the irradiated films for different
intervals in monomer solution. After the grafting, copper
was attached on the surface of the films for measuring thepeel strength between the metal and the grafted-films.
Figure 1 shows the effect of grafting on the peel strength ofthe metal / grafted-PTFE. It is noted that a large increase in
the peel adhesion strength was obtained by the graftpolymerization on the PTFE surface. The increase in theadhesion strength between the metal and grafted films canbe ascribed to cross-linking reaction or covalent bonding
between the copper ion and the carboxyl group of an acrylicacid (AAc) introduced onto the thin surface layer of thePTFE films.
The dielectric constant measured by a cavity resonancemethod is shown in Fig. 2. The values of the dielectric
constant were not significantly changed by the surface
treatment. It suggests that the radiation grafting does notaffect the composition of the PTFE surfaces.
By using a micro fabrication technology EF2, ultrafine
pattern such as 15 μm line width and 6μm gap widthwithout side edges can be formed. Applying this technology
for fabrication of planar-type antennas on the fluororesin
substrates, we have performed an experimental productionof microwave antennas having 16 elements andmillimeter-wave antennas having 240 elements. It was
found from the evaluation of their radiation characteristics
that they have good radiation patterns. The application of
the antennas to biomedical measurement system, remotemonitor of heart pulse and respiration is now in progress.
In summary, PTFE films have been modified byradiation-induced graft polymerization using AAc todevelop low-loss millimeter-wave antennas. As a result of
the treatment, the peel adhesion strength on the PTFE was
improved to be 1.64 kgf/cm. In addition, the values ofdielectric constant were confirmed not to be significantly
changed, which is suitable for the antenna application.
Further investigations are necessary to realize low-loss

devices, such as antennas, filters and non-linear
transmission lines, by using radiating grafting and EF2
fabrication technique.
References
1) Sung R. Kim, J. Appl. Polym. Sci. Vol.77 (2000)
1913-1920.
2) Asaf A. Benderly, J. Appl. Polym. Sci. Vol.VI No.20(1962) 221-225.
3) Shaoyu Wu, E.T.Kang, Neoh, C.Q.Cui and Thiam
Beng Lim, IEEE Transactions on Advanced Packaging.
Vol.23 No.3 (2000) 538-545.

Fig.1 Peel strength of metal / AAc / PTFE as a function ofdegree of grafting.

Fig. 2 Dielectric constant of the films as a function ofdegree of grafting.
Degree of Grafting [%] = (w2-w1) / (w1) ×100
w1 = Weight before Grafting,w2 = Weight after Grafting－ 37 －

JAEA-Review 2007-060

2-04 Preparation of Ampholite-immobilized Interface by
Radiation-induced Grafting
a)

a)

a)

b)

A. Iwanade , D. Umeno , K. Saito , A. Katakai and M. Tamada
a)

b)

b)

Department of Applied Chemistry and Biotechnology, Chiba University, Environment andIndustrial Materials Research Division, QuBS, JAEA

Three types of ampholites containing dimethylamino and carboxyl groups, i.e., N(CH3)2(CH2)nCOOH (n = 1-3), were introduced into
an epoxy-group-containing polymer brush grafted onto a porous hollow-fiber membrane with a porosity of 70 % and pore size of 0.36
μm. Lysozyme was captured by the amphoteric polymer brush during the permeation of a lysozyme solution buffered with a carbonate
buffer (pH 9.0) across the ampholite-immobilized porous hollow-fiber membranes. The N(CH3)2(CH2)2 COOH-immobilized porous
membrane exhibited a five fold higher flux for the buffer solution and a 50-fold lower binding capacity for lysozyme at a lower molar
conversion of the epoxy group into the amphoteric group, up to 17 %, than the other two kinds of membranes.
1. 緒言
高分子製多孔性膜の界面に放射線グラフト重合法を用いて，両性電解質を有するポリマーブラシを固定し、リゾチ
ーム吸着容量と透過流束とを両立できる吸着材料を作製した1)。両性電解質固定高分子鎖のコンホメーションは電荷の中和の度合い2)により支配される。そこで、本研究では
電荷中和の度合いを調節するために、ジメチルアミノ基とカルボキシル基との間のメチレン基数を変化させた両性電解質を多孔性膜に固定し、その性能を評価した。
2. 実験
1） PE多孔性膜への両性電解質の固定 両性電解質固定ポ
リマーブラシを付与した多孔性膜の作製経路をFig. 1 に示す。ポリエチレン製多孔性中空糸膜に電子線を照射後、グリシジルメタクリレート（GMA）をグラフト重合した。化
学式N(CH3)2(CH2)nCOOHによって表される両性電解質の
水 / 1,4-ジオキサン溶液（v / v = 1 / 1）を用いてエポキシ基の一部を開環したのち、残存するエポキシ基をジオール基へ転化した。ここで、メチレン基の数nは 1 から 3 と変化させた。

量））の最大値を比較すると n = 1 および 3 の膜は、それぞれ 16 および 8 であった。Ly を多層に吸着できたのは、荷電中和よりも荷電反発の効果の方が強いためである。n = 1
および 3 の膜の場合、転化率 25%まで、Ly 平衡吸着量は理論単層吸着量と同程度であった。一方、n = 2 の膜の場合、
理論単層吸着量の 1/50 であった。どの膜でも緩衝液透過流束の転化率依存性はなかった。ここで、n = 2 の膜は、n = 1
および 3 の膜に比べて透過流束が 5 倍高かった。n = 2 の膜ではポリマーブラシの伸長が抑えられ、他の膜に比べ荷電中和の効果が強いことが示された。両性電解質固定ポリマ
ーブラシにおいて、転化率とメチレン基の数 n を変化させることによって、Ly 平衡吸着量を単層吸着量の 1/50 から
16 倍まで調節できることがわかった。

Fig. 2 Time course of molar conversion of epoxy
group into amphoteric groups.

Fig. 1 Introduction scheme of ampholite into polymer
brushes grafted onto a porous hollow-fiber membrane.
2) 両性電解質固定膜へのタンパク質吸着 リゾチーム（Lyと略記，pI 11）溶液（pH 9.0）を両性電解質固定膜の内面から外面まで一定流量で透過させた。流出液のLy濃度が供給液のそれと一致するまでLy溶液を透過させた。
3. 結果と考察
エポキシ基から両性電解質基への転化率の経時変化をFig. 2 に示す。メチレン基の数 n = 1 および 3 の最終転化率は同程度で、n = 2 はそれの約 1/3 であった。
nが異なる両性電解質固定膜のLy平衡吸着量と緩衝液透
過流束を転化率の関数として Fig. 3 に示す。n = 1 および 3の膜の Ly 平衡吸着量は転化率が 40 %を超えると急激に増加した。Ly 吸着層数（ =（平衡吸着量）/（理論単層吸着

Fig. 3 Equilibrium binding capacities for lysozyme andbuffer fluxes of membranes.
References
1) K. Miyoshi, et al., “Introduction of taurine into polymer brushgrafted onto porous hollow-fiber membrane”, J. Membr. Sci., 264,(2005) 97.
2) R. G. Alargova, et al., “Properties of amphoteric surfactantsstudied by ζ-potential measurements with latex particles”
Langmuir, 14, (1998) 1996.

－ 38 －

JAEA-Review 2007-060

2-05 Hydolophilic Modification of Vulcanised Rubber by
Radiation Graftinga)N. Mizote , A. Katakaib)and M. Tamadab)a)Mitsuba Co.Ltd.,b)Environment and Industrial Materials Research Division, QuBS, JAEA

90

2

Contact angle (deg.)

30wt%
50wt%
70wt%

1

0

85
80
75
70
65
60

0

5

10
15
Dose（kGy）

20

Fig.1 Dose dependence ofthe degree of grafting.

0

Frictional coefficient70
D.G=1.0%
D.G=1.2%
D.G=1.8%

65
60
0

1
2
Time （min）

3

Fig.3 Change of the surface
hardness due to a shift fromwet to dry state.

0.5
1
1.5
2
Degree of grafting （％）

Fig.2 Relationship between
the degree of grafting andthe contact angle.

75
Surface hardness

1.はじめに加硫ゴム製品は摩擦・粘着性の低減、耐摩耗性の向上等を目的として表面処理が行われている。自動車用
ワイパーゴムでは、ハロゲン処理が行われてきたが、最近、グラファイト焼付けコーティングが注目され、払拭摩擦の低減や耐磨耗性の向上に寄与している1)。しかし、これら表面処理によって、ゴム表面の柔軟性が低下し、ガラス追従不良による払拭性の悪化が問題となっている2)。本研究では放射線グラフト重合法による加硫ゴム表面の親水化について検討し、摩擦低減と払拭性の双方の向上が可能なワイパーゴム表面処理技術
としての可能性を評価した。
2.実験方法ゴム基材として、カーボンブラックを配合した厚さ2mmの架橋天然ゴム用いた。2-ヒドロキシエチルメタク
リレート(HEMA)のグラフト重合では、水を溶媒として用い、モノマー濃度30~70 wt%、照射線量10~25 kGyの範囲で電子線同時照射グラフト重合を行った。グラ
フト率はグラフト前後の重量増加から算出した。加硫
ゴム表面に対する水の接触角は協和界面科学製接触角計により求めた。また表面硬度は高分子計測器製マイ
クロゴム硬度計により求めた。なおウェット状態から乾燥状態へ移行する際の表面硬度変化は、水に濡らしたゴムにおいて、余剰水分を拭き取ってからの表面硬度の経時変化により確認した。摩擦の測定はピンオン
ディスク型摩擦試験機を用い、ガラスディスクとグラフトした架橋天然ゴムとの間の乾燥摩擦係数を測定した。
3.結果および考察
電子線同時照射法により加硫ゴムにHEMAをグラフ
ト重合したときの、グラフト率の照射線量依存性をFig.1に示した。照射線量の増加に伴いグラフト率は上昇し、またモノマー濃度が高いほどグラフト率が高くなった。この結果から、加硫ゴム表面へのHEMAのグ
ラフト重合は照射線量とモノマー濃度により制御できることが分かった。次にHEMAのグラフト重合における接触角のグラフト率依存性をFig.2に示した。HEMAのグラフトに伴い接触角は70°まで低下した。これらの結果からHEMAの電子線同時照射グラフト重合により加硫ゴム表面の親水化が可能である事が分かった。
Fig.3にウェット状態から乾燥状態への移行に伴う表面硬度変化を示した。この図で0 minは完全に水に濡れた状態で、経過時間3 minは完全に乾燥した状態である。

Degree of grafting （％）

Rubber wiper is generally chlorinated to improve the properties such as friction, adhesion and abrasion. However,chlorination causes the degradation of wiping performance owing to the hardening of rubber surface. Thus, a novel
technology of surface modification is inevitable to decrease the environmental burden of chlorination. In the present study,hydrophilic modification of vulcanised rubber by radiation grafting is evaluated as a new surface treatment for the blade
rubber.

0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

Chlorination

0

0.5
1
1.5
Degree of grafting （％）

Fig.4 Relationship between
the degree of grafting andthe coefficient of friction.

グラフト率が1.8 ％になると、加硫ゴムはウェット状態
で表面硬度が低下する。またグラフト率が高くなるほどウェットと乾燥状態での表面硬度差が大きくなる事が確認できた。ウェット状態でゴム表面が軟化する事
により、ワイパー雨滴払拭時のガラス追従性向上による高い払拭性が期待できる。次に電子線同時照射法により加硫ゴムにHEMAをグラフト重合したときの、摩擦係数のグラフト率依存性をFig.4に示した。HEMAのグラフトにより摩擦係数は低下し、その値はハロゲン処理を下回ることが確認できた。これらの結果から、HEMAの電子線同時照射グラフト法はワイパーゴムの表面処理として満足できる摩擦特性が得られ、さらに従来にない摩擦低減と払拭性の双方を向上するワイパ
ーゴム表面処理技術として有望であることが分かった。
References
1) 前川道信,大倉重喜,トライボロジスト 50, 677(2005).

2) 小暮勇治, 日本ゴム協会誌 65, 287 (1992)－ 39 －

JAEA-Review 2007-060

2-06 Emulsion Graft Polymerization of Vinyl Acetatea)a)M. Tamada , N. Seko , Y. Wadab)and H. Mitomob)a)Environment and Industrial Materials Research Division, QuBS, JAEA,b)
Faculty of Engineering, Gunma University

Grafting of vinyl acetate (VAc) on the surface ofpolyhydroxybutylate
(PHB)
film
depresses
thebiodegradability of PHB. After saponification of graftinglayer, the graft chains of VAc were converted into
biodegradable polyvinylalcohol. As a result, VAc-grafted
PHB recovered intrinsic biodegradability1). This grafting canlead that the PHB in use can not be degraded biologicallyand then its waste can be decomposed after alkalinesaponification. Such characteristic of VAc-grafted PHB isapplicable in the cabinet of household electrical appliances.
To impart this property of off-on control of biodegradability,
the grafting of VAc on PHB is inevitable. However, thegrafting yield is so low that VAc solution more than 80 %should be used. It is found that emulsion of VAc in water
could dramatically improve the grafting yield. In the present
study, the reactivity in the emulsion grafting of VAc on
PHB was compared with that in the methanol solvent.
PHB film, 150 µm thick, was prepared by thermalpressing of PHB powder (Mn=3.3×105). The film obtained
was cut into the sample, 10mm×60mm, for grafting andthen irradiated with 10kGy of electron beam in nitrogen gas.
Irradiation of electron beam simultaneously induces thedegradation of PHB. Molecular weight was reduced 45% of
the initial value after irradiation of 10 kGy and 32 % at 50
kGy. The tensile strength decreased 10 % at 50 kGy2).
Hence, the irradiation dose for grafting was restricted to 10
kGy to minimize the damage of trunk PHB.
The irradiated PHB film was put into glass reactor and
150 ml of VAc emulsion was added into the same reactor. to

25

Emulsion systems
Surfactant
concentration
0.3％
0.5％
0.7％

20

References
1) Y. Wada et al., Radiat. Phys. Chem. 76 (2007) 1075 .
2) Y. Wada et al., J. Appl. Polym. Sci. 101 (2006) 3856.

15
Dg［％］

stabilize the VAc micelles in water at 60 °C. VAc of 5 %was suspended in Nonion L-4 of the concentration from 0.2
to 1%. Instead of VAc emulsion, methanol and waster wereused as solvents. The reactor was maintained at 60°C tocarry out the VAc grating. The grafting reaction was
evaluated by degree of grafting (Dg):
Dg[％]=(Wg-W0)/W0×100
where W0 and Wg are weight of PHB films before and aftergraft polymerization, respectively.
Figure 1 shows the degree of grafting in VAc emulsions,
100 % VAc and 80 % VAc in methanol. In the emulsion
grafting, Dg was affected by the concentration of Nonion
L-4. At 0.5 ％, Dg reached the maximum value of 23 % at
the grafting time of 5 h. The micelle size of VAc wasminimized at 0.4 μm. In the case of 80 % VAc in methanol,
Dg was only 9 % at the grafting time of 5 h. This value ofDg was two fifth of the emulsion grafting. When 100 % of
VAc was used, the Dg obtained was lower than those of theemulsion graftings.
The percentage of monomer consumed in the grafting
was evaluated as monomer reactivity. The monomer
reactivities of the grafting in water, emulsion, and methanol
listed in Table 1. Since the VAc less than 2 % can be
dissolved in water, the grafting data in 2 % water werecompared. Monomer reactivities were 0.62 %, 1.01 %, and
0.010 % for the grafting in water, emulsion, and methanol,
respectively. In the methanol, the monomer reactivity
increased with the increment of monomer concentration. At
100 % VAc the monomer reactivity became 0.046 % which
is lower than that in water and emulsion of 2 % VAc. The
maximum reactivity was realized at emulsion grafting. The
reactivities were around 1% in both VAc concentrations of 2
and 10% in the emulsion grafting.

VAc=100

10

Table 1 Monomer reactivities of the grafting in water,emulsion, and methanol in various concentrations ofmonomer.

VAc/MeOH =80/20

5
0
0

1

2
3
4
Grafting time［ｈ］

5

6

Solvent
Water

Fig. 1 Degree of grafting (Dg) in VAc
emulsions, 100 % VAc and 80 % VAc inmethanol. Polyoxyethylene monolaurate(Nonion L-4, NOF Co.) was used assurfactant in emulsion grafting.

Water
Water(emulsion)
Water(emulsion)
Methanol
Methanol－ 40 －Monomer
concentration
［％］

Dg
［％］

1
2
2
10
2
80

2.6
4.8
7.8
35.0
0.1
9.4

Monomerreactivity
［％］
0.68
0.62
1.01
0.91
0.010
0.030

JAEA-Review 2007-060

2-07 Adsorption Performance of Graft Amine Adsorbent for
Au(III)
N. Seko and M. Tamada
Environment and Industrial Materials Research Division, QuBS, JAEA
before and after grafting. The resultant grafted-NF wasreferred to as AAm/MAA (x/y, Dg) or AAm/NVA (x/y, Dg)
grafted-NF, where x/y and Dg designate the weight ratio of
AAm/MAA or AAm/NVA in the monomer mixture and thedegree of grafting, respectively.
Figure 1 shows the distribution coefficient of AAm/MAA
and AAm/NVA adsorbents along with weight percent of
AAm in the monomer. The D of AAm/NVA (50/50, 88)
was 5x105. This value was nine times higher than that of
AAm/MAA (50/50, 100). The column mode study was
conducted by using a column packed with the adsorbent
named AAm/NVA (50/50, 88). Column-mode study was
conducted by supplying a feeding solution of pH 3
containing 1 mM of Au(III) to the column at flow rates of
260, 520, or 1040 h-1 in space velocity (SV). These
breakthrough curves are shown in Fig. 2. Although the
breakthrough point slightly decreased at the extremely highflow rate of 1040 h-1, there are no large differences in the
bed volume (BV). The flow rate of 1040 h-1 is 100 times
faster than that of general granular resin packed column.
The breakthrough points of three flow rates were 163, 150
and 144 BV, respectively. Respective breakthroughcapacities were 2.76, 2.18 and 1.95 mmol/g of Au(III) on
AAm/NVA.
References
1) K. Fujiwara, Kagakukogaku. 55(1) (1991) 21.
2) N. Seko et al., Nucl. Instr. Meth. Phys. Res. B 135(2005) 21.

10

6

1.0

10

5

0.8

10

4

0.6

10

3

0.4

SV [h -1]

2

0.2

260
520
1040

10

C/C0

Distribution coefficient

To meet the demand for rare noble metals, it is necessary
to reduce the amount of noble metals involved in catalysts
to save the amount of such noble metals used in catalysts orincrease the recycle rate of waste catalysts1). Recovery ofthese metals from waste catalysts is carried out by a wet
process which comprise of dipping waste catalysts in astrong acid to dissolve the noble metals, and separating andpurifying these metals from the resulting solution by an ion
exchange method using chelate resin beads or by a solvent
extraction method using a chelating reagent. However, thewet process has such disadvantages that diffusion of metal
ions in the chelating resin beads is a rate-determining step inthe recovery from low-concentrated metal solutions; theconcentration efficiency is low, etc.
The objective of this study is the preparation of a new
fibrous adsorbent containing amino groups for Au(III). A
combinationofmethacrylic
acid
(MAA)
or
N-vinylacetamide (NVA) with allylamine (AAm) was
co-grafted onto the nonwoven fabric (NF) using by
pre-irradiation techniques2). The NF was irradiated with anelectron beam up to 200 kGy in nitrogen atmosphere atambient temperature. The irradiated NF was immersed in amonomer solution immediately deaerated by bubbling withnitrogen gas. The total concentration of the two monomers
was set at 50 (wt/v) % in H2O as a solvent, where the weightratio of AAm/MAA or AAm/NVA in the monomer mixture
ranged from 90/10 to 10/90. Co-grafting was performed at
313 K for a reaction time up to 8 hours. The degree ofco-grafting (Dg) was calculated from the weight gain by

AAm/NVA:100 ppb
AAm/MAA:100 ppb

10

0

0

20

40

60

80

0

100

W eight% AAm in the monomer mixture, x [%]Fig.1 Distribution
adsorbents.

coefficientfor Au(III) on AAm

100

200

300

400

500

600

e d volume [-]Bed
B

Fig.2 Effect of flow rate with 1mM Au(III) solution at
pH3.

－ 41 －

JAEA-Review 2007-060

2-08 Synthesis of Graft Adsorbent with
N-methyl-D-glucamine for Boron Adsorption
H. Hoshina, N. Seko, Y. Ueki and M. Tamada
Environment and Industrial Materials Research Division, QuBS, JAEA
Boron is widely distributed in the environment more
often as boric acid or borate salt which is harmful to humanorganism, therefore WHO revised a drinking water
guideline for boron in 1998. In response to this, a boron
effluent standard was limited at 10 ppm in the waterpollution control law in Japan. Then, it is expected that
regulation for boron is more severe in near future. The mostcommonly used removal techniques for boron are chemicalclarification and ion-exchange of granular resin having
N-methyl-D-glucamine (NMDG). The chelating adsorbents
having NMDG have been extensively investigated because
NMDG has high affinity for boron adsorption1). Howeverconventional adsorbents had a slow adsorption rate, andwere difficult to adsorb a low concentration of boron
efficiently. Therefore, we have been developed a new
method to make more effective adsorbents for boron
removal.
A non-woven polyethylene fabric as a trunk polymer
purchased from Kurashiki MFG. Co. was irradiated byelectron beam at voltage of 2 MeV, and current of 3 mA.
Radiation induced grafting of glycidyl methacrylate (GMA)
onto non-woven polyethylene fabric in aqueous medium
with 0.05 wt% Tween20 as a surfactant in the presence ofwater was investigated. The Dg of 200 % was obtained with
5wt% GMA at 20 kGy for 60 min, which is enough formetal adsorbents. GMA-grafted fabric was chemicallyconverted to NMDG. The maximum density 2.4 mmol/g of
NMDG could be given by 5 wt% NMDG at 80 ℃ for 1 h.
To compare the boron adsorption performance of graft
adsorbent with granular resin (NMDG density 2.2 mmol/g,

particle size 0.8 mm), the column-mode adsorption was
conducted. Column-mode adsorption was carried out by
using the 10 ppm of boron solution at pH 7 at various flow
rates. The characteristic of breakthrough was evaluated byplotting C/C0 which was the value of outflow concentration
divided by the injecting concentration against bed volume(BV) as shown in Fig. 1. When the breakthrough point wasdetermined at C/C0 of 0.05, the BV values at the
breakthrough point were 235 and 138 of the graft adsorbent
and the granular resin at SV10 h-1, respectively. Figure 2
shows the effect of flow rate on BV at the breakthroughpoint of the graft adsorbent and the granular resin. The BV
at the breakthrough point increased with decreasing flow
rate. The BV at the breakthrough point of the graft
adsorbent is higher than that of the granular resin at any
flow rates. At the flow rate of SV50 h-1, the result impliedthat the graft adsorbent has 4 times higher breakthroughcapacity than the granular resin. The breakthrough capacityof the graft adsorbent at SV100 h-1 gave the same one withthe granular resin at SV10 h-1. This result indicates that thegraft adsorbent can adsorb boron 10 times faster than the
granular resin.
Reference
1) N. Kabay, I. Yilmaz, S. Yamac, S. Samatya, M. Yuksel,
U. Yuksel, M. Arda. M. Saglam, T. Iwanaga, and K.
Hirowatari, Reactive & Functional Polymers, 60, 163-170(2004).

250
BV at breakthrough point [-]

1.0

C/C0

0.8
0.6
0.4
0.2
0
0

100

200

300
BV [-]

400

500

200
150
100
50
0
0

Fig.1 Breakthrough curve of graft adsorbent( ● ) andgranular resin(▲) at SV10 h-1

50
SV [h -1 ]100

Fig.2 Effect of flow rate on BV at breakthrough point ofgraft adsorbent(●) and granular resin(▲)－ 42 －

JAEA-Review 2007-060

2-09 Development of Bifunctional Iminodiacetic Acid Fiber
a)

a)

a)

b)

A. Jyo , A. Ikegami , H. Matsuura , M. Tamada , A. Katakaib)a)and N. Seko b)b)Graduate School of Science and Technology, Kumamoto University, Environment andIndustrial Materials Research Division, QuBS, JAEA

In this work, first, the monofunctional iminodiacetic acidfiber was prepared from polyethylene-coated polypropylene
fiber (PPPE) grafted with vinylbenzylglycidylether (VBGE)
according to Scheme 1. Electron (200 kGy) irradiated PPPE
(0.9 denier, length 3.8 cm) was immersed in dimethyl
sulfoxide solution of VBGE (50 weight %) for 24 h at 50 oC,
and the weight increase of the resulting VBGE grafted
CH2

HC ( CH2CH )nN

CH2COOC2H5
CH2COOC2H5CH2120 oC, 5 h, EtOH

CH2

HC ( CH2CH2CH2CH2 O CH2 CH CH2OCH )nC2H5OOCCH2N
C2H5OOCCH2CH2 O CH2 CH CH2
FGEI-ester

PPPE-g-VBGE

Table 1 Properties of bifunctional iminodiacetate acidfibers in the H+ form
Precursor

Objective
Fiber

TGa)
(h)

WIb)
(%)

N content(mmol/g)

S content(mmol/g)Acid capacity(meq/g)PGEI-ester

FGEIS1

5

44.5

1.03

1.27

4.3

7

60.3

0.907

1.57

4.6

PGEI(Na+)FGEIS2

5

112

0.764

2.34

4.5

5

104

0.667

2.47

4.5

PGEI(H+)

FGEIS3

3

123

0.810

2.31

4.0

5

191

0.589

2.47

4.2

OH

CH2
1 M NaOH, 100 oC 12 h
1 M HCl
pH 2 HCl

HC ( CH2
CH2
CH2

CH )n
HOOCCHN
HOOCCH2CH2 O CH2 CH CH2
2

FGEI

OH

a) Time for graft polymerization. b) Weight increase

Scheme 1 Preparation of iminodiacetic acid fiber
PPPE (PPPE-g-VBGE) was 91% of the weight of the trunk
PPPE. PPPE-g-VBGE was functionalized by heating in
ethanol solution of diethyl iminodiacetate (67 volume %)for 5 h at 120 oC using a stainless steel autoclave. After
alkaline hydrolysis of ester groups, the resulting fiber FGEI
shown in Scheme 1 was finally equilibrated with a dilutehydrochloric acid of pH 2, and was dried in vacuum.
Nitrogen content and acid capacity of FGEI were 1.7mmol/g and 4.2 meq/g, respectively.
FGEI exhibited excellent performances in column-mode
uptake of divalent metal ions from solutions of neutral pH.
For instance, breakthrough capacity of Zn(II) is as high as
ca. 0.5 mmol/g at high flow rate of 1000 h-1 in spacevelocity (SV). On the other hand, trivalent metal ions suchas Fe(III) must be treated in strongly acidic solutions lessthan pH 2 to avoid their precipitation as hydroxides. Under
such strongly acidic conditions, polymer boundiminodiacetic acid groups exist as electrically neutral or
positively charged species, which interfere with uptake oftrivalent cations. Then, the second purpose of this work is toresolve this problem. The introduction of sulfonate as
second functional group is expected to be effective, because
sulfonate exists as anionic species irrespective of pH.
Negatively charged sulfonate enhances swelling of thepolymer phase and also reduces the undesirable effect ofpositively charged species [-HN+(CH2COOH)2]. However,the sulfonation of FGEI with chlorosulfonic acid andsulfuric acid resulted in marked weight loss of the fiber (ca.
30 %). This is probably due to cleavage of ether bonds by
the strong acids. Then, we have examined the electron

and changed into the H+ form (FGEIS1). The other two
SSS
grafted fibers FGEIS2 and FGEIS3 were also changed into
the H+ form. Results for graft polymerization of SSS aresummarized in Table 1, which shows that the reactivity of
SSS in the electron irradiation induced graft polymerization
increases in the order FGEI-ester < FGEI(Na+) < FGEI(H+).
However, too much SSS was introduced in cases of
FGEIS2 and FGEIS3, and then the effect of grafted SSS on
uptake of Fe(III) was
1.2
examined by using
1
FGEIS1. The results
are shown in Fig. 1.
0.8
The monofunctional
0.6
iminodiaceticacid
FGEI SV 50
FGEIS1 SV 50
0.4
fiber FGEI can not
FGEIS1 SV 100
FGEIS1 SV 200
effectively take up
0.2
FGEIS1 SV 500
FGEIS1 SV 1000
Fe(III) at pH 1.5. On
00100 200 300 400
500
600
the contrary, theVolume of feed (mL/mL-F)
bifunctional
fiberFig. 1 Column-mode uptake of
FGEIS1 can take up
Fe(III) by FGEI and FGEIS1.
Fe(III) even at highColumn: FGEI 1.2 mL (0.35 g),-1
flow rate of 1000 h
FGEIS1 1.0 mL (0.35 g). Feed:in SV. FGEI and
0.001 M Fe(III) pH 1.5. SV
FGEIS1gavemeans space velocity (h-1).
breakthroughcapacities of 0.09 and 0.61 mmol/g for Fe(III) at the feedflow rate of SV 50 h-1, respectively. Thus, the electron
irradiation induced graft polymerization is useful for
preparation of bifucntional chelating fibers containing
sulfonate without use of harmful acids.

－ 43 －

C/C0

CH2

irradiation induced graft polymerization of sodium
styrenesulfonate (SSS) onto FGEI.
FGEI-ester, FGEI in Na+ form, and FGEI in H+ form were
irradiated by electron (200 kGy) and they were immersed in
an aqueous solution of SSS (16.7 weight %) at 40 oC for agiven time. FGEI-ester grafted with SSS was hydrolyzed

JAEA-Review 2007-060

2-10 Preparation of Graft Adsorbent with Ultrafine Non
Woven Fabrica)F. Basuki , N. Sekob)

and M. Tamadab)a)Center for Education and Training, National Nuclear Energy Agency, BATAN,b)
Environment and Industrial Materials Research Division, QuBS, JAEA
very strong band at 1732 cm-1, which were characteristic ofcarbonyl group, and the peaks at 1262 cm-1 and 1151 cm-1
correspond to P=O and O-P-O bonds in phosphoric group,
respectively. In the SEM photos, the average diameter of
UFPE of non-grafting, Dg of 59, 110, 168, 189, 299, and
479 % were 2.3, 2.6, 2.8, 3.0, 3.2, 3.4 and 3.6 µm,
respectively. As a conclusion, by using UFPE the optimum
grafting condition had been improved as follows; the dose
was 50 kGy, 20 % monomer-2 %SDS in water solution, 60oC and 3 hours which Dg reached 230 %.
References
1) Basuki F. Seko N, Tamada M, Sugo T, Kume T, J. Ion
Exchange,14A, 209 (2003).
2) Seko.N, Tamada M, Yoshii F, Nucl. Instr. Meth Phys.
Res. B, 236, 21 (2005).

－ 44 －

800.0
Degree of Grafting (%)

The chelating adsorbent containing phosphoric group has
been extensively investigated because of its uniqueselectivity to the metal ion. We have prepared fibrous
phosphoric chelating adsorbent (FPCA) direct synthesizedby radiation induced graft polymerization. It has been
demonstrated that FPCA had good ability to remove toxic
metals such us Pb and Cd 1). This adsorbent also had 200
times higher distribution coefficient for uranium than that ofa commercial adsorbent al low pH 2). Although the FPCA
was successfully prepared for industry application, theoptimum grafting condition (200 kGy dose, 20 % monomer,
10/90 wt% methanol-water, 12 h reaction time at 60 oC
which degree of grafting reached 250 %) need to be
improved. In the present study we have made improvement
by using ultrafine non woven fabrics to get optimum
condition of grafting.
Polypropylene coated polyethylene (PPPE, diameter was
15 µm) and Polyethylene non-woven fabrics (UFPE,
diameter was 2 µm) were cut into rectangular shape (3 cm x5 cm) and placed into polyethylene bag. After de-aerated
with nitrogen gas, samples were irradiated with electron
beam in dry ice condition. The irradiated samples were
contacted with phosphoric acid monomer solution(2-hydroxyethyl methacrylate phosphoric acid (HMPA) in
SDS/methanol-water) in de-aerated glass ampoule andmaintained at desired reaction time and temperature in waterbath. At the completion of grafting, the graft copolymer waswashed by methanol.
The ability of grafting between PPPE and PE polymer isshown in Fig 1. Radiation dose used was 100 kGy, 30 %monomer, 60 oC reaction temperature. The degree grafting(Dg) for UFPE reached 750 % for 6 hours and for PPPE thehighest Dg was 93 %. In graft reaction, because the total
surface area increased with decreasing the diameter of fiber
Dg increased. The Dg in 2 % SDS solution was higher thanmethanol and no homo-polymerization observed. So 2 %SDS can be replaced of previous condition. Since thegrafting rate of UFPE was high, grafting conditions could be
optimized to 50 kGy of dose, 20 % monomer, 60 oC and 3
hours. From the FTIR spectra, the grafted samples have a

700.0
600.0
500.0
400.0
300.0
200.0
100.0
0.0
1

2 3 4 5 6Reaction time (h)Fig.1 Dg of HMPA at various reaction times.
▲:PE/100 kGy/30 %monomer/2 %SDS,◆:PPPE/100 kGy/30 %monomer/2 %SDS,■:PE/100 kGy/30 %monomer/10 %MeOH,●: PE/50 kGy/20 %monomer/2 %SDS

7

JAEA-Review 2007-060

2-11 Synthesis of Graft Adsorbent with Amine Groups onto
Polylactic Acid Nonwoven Fabrica)b)

L. D. C. Nayanajith , Y. Ueki , N. Sekoa)b)

and M. Tamadab)b)Industrial Technology Institute, Sri Lanka, Environment and Industrial Materials Research
Division, QuBS, JAEA

Introduction
Graft adsorbents, which can rapidly remove andeffectively recover metal ions from water resources, areattracting a lot of attention as sophisticated metal adsorbents.
However, the most of them were synthesized frompetroleum materials1). If plant-derived polymer, such as
polylactic acid (PLA), is used as trunk polymer for graftpolymerization, the consumption of petroleum can be
reduced, and besides the reduction of environmental
burdens is brought because of biodegradable property ofthemselves. In the present study, the preparation of
PLA-based metal adsorbent was eagerly attempted by using
radiation-induced graft polymerization.
2.

Expermental
PLA nonwoven fabrics (a basis weight of 120 g/m2) were
irradiated with a certain dose of electron beam in nitrogen
atmosphere. The grafting was carried out by immersing theirradiated fabrics into the aqueous emulsion solution
consisting of 4-chloromethylstyrene (CMS), Tween 20(surfactant) and deionized water. After grafting, theCMS-grafted samples were further treated with 50 wt%
ethylenediamine (EDA) in isopropyl alcohol (IPA) at 60°C.
The degree of grafting (Dg) was estimated by the increased
weight after grafting, and the amine group density wasdefined by the nitrogen content of EDA-modified adsorbent,
respectively. The metal adsorption capacity was individually
evaluated through the batch adsorption experiments. The
batch adsorption tests were carried out by dipping theadsorbent of 30 mg into 50 mL of each metal ion solution of
100 ppm at 25 °C for 24 h.

and sufficient mechanical strength, the effect of compositionof modification solvent on the introduced functional groups
was investigated. As a result of trial and error, 50 wt% EDA
in IPA was found to be the optimum condition, and then its
EDA group density was 3.0 mmol/g-adsorbent.
The EDA-modified adsorbent showed higher affinity to
Cu2+ and lower affinity to Cd2+, Pb2+ and Zn2+. As seen in
Fig. 2, this adsorbent could effectively capture metal ionsfrom weak acid and neutral solutions, and then theequilibrium adsorption amounts for Cu2+ at pH 5.2 and Cd2+,
Pb2+ and Zn2+ at pH 7 were 2.5, 0.37, 0.23 and 0.21
mmol/g-adsorbent, respectively.
Reference
1) N. Seko, M. Tamada and F. Yoshi, Nucl. Instr. Meth.
Phys. Res. B, 236 (2005) 21–29.

90
60
30
0

0

5

10

15

20

Reaction time [h]Fig.1 Effect of reaction time on Dg.

3.

－ 45 －

Amount of adsorbed metal ions[mmol/g-adsorbent]

Results and Discussion
In this work, irradiation dose of 100 kGy, CMS
concentration of 3 wt%, Tween 20 concentration of 0.3 wt%
and reaction temperature at 40 °C were optimum conditions
for CMS grafting onto PLA. As shown in Fig. 1, the Dg of
PLA nonwoven fabric can be controlled in the range of up
to 115 % under the optimal graft polymerization conditions.
However, the optimal graft polymerization time wasdetermined for 4 hours because the homopolymerization of
CMS was occurred after 4 hours, and then the Dg at 4 hours
reached about 80 % (2.8 mmol-CMS/g-adsorbent).
In the modification process of CMS-grafted PLA with
EDA, PLA was readily hydrolyzed by EDA, and its
mechanical strength decreased. Therefore, to prepare
PLA-based metal adsorbents with adequate performance

120

Degree of grafting [%]

1.

0.4
0.3
0.2
0.1
0

1

2

3

4

5

6

7

pH
Fig.2 Effect of pH on adsorption of Cd2+ (△), Pb2+(●) and Zn2+ (□) on EDA-modifiedadsorbent (3 mmol-EDA/g-adsorbent).

JAEA-Review 2007-060

2-12 Preparation of New Adsorbent Containing Hydroxamic
Acid Groups by Grafting for Metal Adsorption
a)

b)

b)

S. Phiriyatorn , H. Hoshina , N. Seko and M. Tamadab)a)Thailand Institute of Nuclear Technology,
Environment and Industrial Materials Research Division, QuBS, JAEAb)Introduction
Hydroxamic acid groups can form complexes withvarious metal ions such as Cd2+, Fe2+, Fe3+, Zn2+, Pb2+, Ni2+,
Hg2+, Au3+, Ag+, Cu2+, Co2+, Cr3+, and UO22+ 1-3). In thepresent work, a new adsorbent containing hydroxamic acidgroups was synthesized by radiation-induced graft
copolymerization of methyl acrylate (MA) onto nonwoven
fabric composed of polyethylene-coated polypropylene fiber.
Graft copolymerization was carried out in MA emulsion
containing sodium dodecyl sulfate (SDS) as an emulsifier inthe presence of water. Grafting polymerizations werestudied with regard to various parameters of importance:
dose, concentration of MA, reaction time, reaction
temperature, and concentration of SDS. Conversion of theester groups of the grafted copolymer into the hydroxamic
groups was performed by treatment with an alkaline
solution of hydroxylamine (HA).
Experiment
The trunk polymer fabrics were packed in a polyethylene
bag under nitrogen atmosphere. After irradiation, fabrics
were placed into a glass ampule and were evacuated. The
deaerated MA solution was transferred into the ampule. The
grafted copolymers were reacted with hydroxylamine in amethanol-water mixture at 75 ºC to convert the ester groupsof grafted copolymer to hydroxamic acid groups. The
percentage conversion was determined by elemental
analysis.

Result and Discussion
Degree of grafting increased with increasing dose, MA
concentration, reaction temperature, and reaction time anddecreased with an increasing SDS concentration. The
grafted copolymer produced with 2 % MA, 0.1% SDS wt/v
water, dose 20 kGy, reaction time 1 h, and reaction
temperature 40 ºC gave degree of grafting 120 % (6.33mmol/g of MA group) (Fig.1). The maximum percentage
conversion of the ester groups of the grafted copolymer into
the hydroxamic groups was 60 % at optimum condition:
20 % HA in methanol-water ratio (5:1), pH 13, reaction
time 1 h, and 1 g of trunk polymer. The FTIR spectrum ofgrafted copolymer shows a new characteristic absorption
band of an ester at 1725 cm-1 due to C=O stretching modein addition to the same adsorption bands of trunk polymer asshown in Fig. 2 while the FTIR spectrum of modified
copolymer shows the characteristic absorption bands ofhydroxamic acid (C=O at 1711 cm-1) and amide (N-H at
1629 cm-1). Adsorbent containing hydroxamic acid groups
can adsorb 99 % of UO22+, 98 % of V5+, 97 % of Pb2+, and
96 % of Al3+ at pH, 5, 4, 6, and 4, respectively after
contacted with 100 ppb metal solution for 24 h.
References
1) H. L. Yale, Chem. Rev., 33, 209 (1943).
2) R. M. Mendez, V.N. Sivasankara Pillai, Talanta, 37,
591 (1990).
3) Y. K. Agrawal, H. Kaur, S.K. Menon, React. Funct.
Polym., 39, 155 (1999).

100

300

90
80
70
60

200

50

(b)

40
30
20

100

(c)

-C=Ostr .

TransmittanceD egree of G rafting (% )

(a)

10
0
-10
-20

-C=O,-N-H

0

-30

0

100

200

300

400

4000

Reaction Time (min)Fig 1. Effect of reaction time on degree of grafting.

3500

3000

2500

2000

1500

1000

500

cm-1

Fig 2. FTIR spectrum of (a) trunk polymer, (b) grafted
copolymer, (c) adsorbent .

－ 46 －

JAEA-Review 2007-060

2-13 Preparation and Characterization of Polylactic Acid
Nonwoven Fabric-based Metal Adsorbent
Y. Ueki, N. Seko, H. Hoshina and M. Tamada
Environment and Industrial Materials Research Division, QuBS, JAEA
1.

Introduction
The graft adsorbent has been attracting attention as a
sophisticated metal adsorbent because the adsorption rate is
10–100 times higher than that of a commercially available
particulate resin1). However, these adsorbents are originatedfrom petroleum resources2). If plant-derived polymer, suchas polylactic acid (PLA), is used as a trunk polymer, thedependence on petroleum resource and the amount ofindustrial waste can be decreased to some extent. In thepresent study, the preparation of PLA-based metal adsorbent
was attempted by using radiation-induced graftpolymerization, and the metal adsorption capacity and theselectivity for various metal ions were evaluated.
Expermental
PLA nonwoven fabrics (fiber diameter: 18 μm) were
irradiated with a certain dose of electron beam in nitrogen
atmosphere at dry ice temperature. The graft polymerization
was carried out by immersing the irradiated samples into theaqueous emulsion solution consisting of GMA, Tween 20(surfactant) and deionized water at the desired reaction
temperature. After grafting, the GMA-grafted samples were
further immersed in 0.5 M of disodium iminodiacetate(IDA-Na) solution at 80 °C. The degree of grafting (Dg)was estimated by the increased weight after grafting, and the
IDA group density of the adsorbent was estimated by theequilibrium adsorption capacity for Cu2+, respectively. The
metal adsorption capacity of the adsorbent was individually
evaluated through the batch adsorption experiments. The
batch adsorption tests were carried out by dipping theadsorbent of 30 mg into 50 mL of each metal ion solution of
100 ppm at 25 °C for 24 h.

Results and Discussion
The optimum grafting conditions were basis weight of
120 g/m2, dose of 50 kGy, GMA concentration of 4 wt%,
Tween 20 concentration of 0.1 wt%, reaction temperature at
40 °C, and the Dg can be controlled in the range of up to
200 % (4.7 mmol-GMA/g-grafted PLA) (Fig.1).
Figure 2 shows the effect of methanol (MeOH)
concentration in the modification medium on the IDA group
density. The IDA group density increased with the increaseof the MeOH concentration. However, at the same time, the
PLA was also damaged by the IDA groups themselves, andits mechanical strength was deteriorated. The IDA group
density of PLA-based metal adsorbent, which had adequate
metal adsorption capacity and sufficient mechanical strength,
was about 500 μmol/g-adsorbent.
The order of metal ion selectivity of the graft adsorbent
was Cu2+ > Pb2+ > Ni2+ > Zn2+ > Cd2+ > Co2+ > Ca2+ > Mg2+
and the equilibrium adsorption capacities for each metal ion
were 488, 423, 418, 317, 284, 207, and 111 μmol/gadsorbent, respectively. Although this selectivity was in thesame order of that of a commercially available particulate
resin (DIAION CR11), its adsorption capacities for heavy
metal ions were within the range from 30 to 80 % of thoseof the DIAION CR11. This difference of the adsorption
capacities was caused by the lower conversion rate, below
25 %, of the GMA-grafted chains in order to maintain thesufficient mechanical strength of the fabrics.
References
1) S. Aoki, K. Saito, A. Jyo, A. Katakai and T. Sugo, Anal.
Sci., 17 Suppl. (2001) i205–208.
2) N. Seko, M. Tamada and F. Yoshi, Nucl. Instr. Meth.
Phys. Res. B, 236 (2005) 21–29.

Amount of IDA group density[μmol/g-adsorbent]

2.

3.

Degree of grafting [%]

250
200
150
100
50
0

0

6

12

18

24

2500

○
Water
▲ 5% MeOH□ 10% MeOH
▼ 30% MeOH
◇ 50% MeOH

2000
1500
1000
500
0

0

6

12

18

24

Reaction time [h]Reaction time [h]Fig. 2 Effect of MeOH concentration on
IDA groups density.

Fig. 1 Effect of reaction time on Dg.

－ 47 －

JAEA-Review 2007-060

2-14 Metal Adsorption of Blend Hydrogels Based on
Carboxymethyl Cellulose and Carboxymethyl Chitosan
a)

b)

a)

a)

A. Hiroki , H. T. Tran , N. Nagasawa , T. Yagi and M. Tamadaa)a)Environmental and Industrial Materials Research Division, QuBS, JAEA,b)
Dalat Nuclear Research Institute, VAEC

It is well known that hydrogels of carboxymethyl
cellulose (CMC) and carboxymethyl chitosan (CMCts) areproduced by gamma or electron beam irradiation with theirhigh concentrated aqueous solution 1). The hydrogels adsorb
metal ions such as Cu and Ca due to the carboxyl group andamino group on the side chain of CMC and CMCts 2). In thepresent report, we report metal adsorption of blendhydrogels prepared by γ-irradiation with the mixtures of
CMC and CMCts. The adsorption of Pb and Au ions onto
the blend hydrogels were controlled with the composition of
the CMC and CMCts.
CMC and CMCts, which were purchased from Daicel Co.
Ltd, Japan and Koto Chemicals Co. Ltd, Japan, respectively,
have a degree of substitution of 0.91, and CMCts has adegree of deacetylation of 84%. The CMC/CMCts aqueous
solution of 30 wt.% (blend ratio of CMC/CMCts: 100/0,
75/25, 50/50, 25/75, 0/100) were sealed in polyethylene
nylon bags for air-free conditions after degassing using
vacuum apparatus. The irradiations were carried out using60
Co γ-ray source at the Takasaki Advanced Radiation
Research Institute, Japan Atomic Energy Agency. The
samples of paste state were irradiated to a total dose of 20 to
200 kGy (a dose rate: 10 kGy/h) at room temperature toobtain blend hydrogels. The gel fraction of the obtainedhydrogels was determined gravimetrically by measuring theinsoluble part after extraction of sol. The metal ion
concentration in a solution was measured by Inductively
Coupled Plasma Mass Spectrometer, and then the adsorption
rate of Pb and Au ions with the hydrogels was calculated.
Figure 1 shows the gel fraction of CMC/CMCts blendhydrogels as a function of irradiation dose. The gel fraction
increased sharply up to 30 kGy and reached a constant value

in the range of 100-200 kGy. An increase in the ratio of
CMC raised the gel fraction of blend hydrogel. According to
gel permeation chromatography, the molecular weight of
CMC and CMCts was 5 x 105 and 6 x 104, respectively.
Therefore, crosslinking of CMC is easier to occur than thatof CMCts in the same condition because of entanglement
between the polymer chains, resulting in the increase in thegel fraction of the obtained hydrogels.
The nitrogen content in the blend hydrogels wasdetermined by means of elemental analysis. The nitrogencontent in the obtained hydrogels was proportional to theratio of CMCts in the mixture, which was almost equal withtheoretical ones. This indicates that the obtained hydrogels
were constructed at the initial ratio of CMC/CMCts.
The relationship between the composition of
CMC/CMCts in the blend hydrogels and the adsorption rateof Pb and Au ions is shown in Figure 2. The adsorption rateof metal ions increased with increasing the composition of
CMCts. The adsorption rate of Pb ions increased from 55 %to about 75-80 % in the presence of CMCts. On the other
hand, in the case of Au ions, the increases in the adsorption
rate appeared clearly. Although the adsorption rate with
CMC/CMCts (100/0) blend hydrogel was slightly 10 %, it
reached 60 % at 75/25 of ratio and increased gradually to
90 %. Therefore, it suggests that the metal adsorption with
the CMC/CMCts blend hydrogels was significantly
influenced by amino group on the CMCts.
References
1) F. Yoshii, et al., Nucl.Instr. and Meth. B, 208, 320-324(2003).
2) N. Nagasawa, et al., JAEA-Review 2006-042, 52 (2007).
100
Adsorption rate (%)

Gel fraction (%)

8060
CMC / CMCts
100 / 04075 / 25
50 / 5020

25 / 75

Au

80
Pb
60
40
20

0 / 100

0

0

50

100
Dose (kGy)

150

200

0
100 / 050 / 50

0 / 100

Composition of CMC / CMCts

Fig. 1. Effect of dose on the gel fraction of CMC/CMCts
blend hydrogels.

－ 48 －

Fig. 2. Adsorption rate of Pb and Au ions with the
CMC/CMCts blend hydrogels.

JAEA-Review 2007-060

2-15 Improvement of Physical Properties of Poly(butylene
terephthalate-co-adipate) / Poly(lactic acid) Blend Filmby Radiation Crosslinking
N. Nagasawa a), P. H. Sarath Kumara b), T. Yagi a) and M. Tamada a)a)Environment and Industrial Materials Research Division, QuBS, JAEA,b)
Rubber Research Institute of Sri Lanka

PLA

to 200 kGy by using an EB accelerator with a dose rate of
10 kGy pass-1. Gel fractions and mechanical properties ofcrosslinked PBTA / PLA blend films were measured bychemical methods and tensile measurements.
Figure 2 shows gel fraction of PBTA / PLA blend filmwith different concentration of TAIC irradiated in EB
accelerator at 50 kGy versus PLA content. PBTA / PLA
blend film without TAIC didn’t form gel. However, PBTA /PLA blend film with over 1 parts per 100 parts resin (phr)TAIC began to form gel at all PLA contents. Gel fraction ofblend film mixed with 3 or 5 phr of TAIC increased steeply
with increasing content of PLA in blend. It was found that
TAIC at upward of 3 % concentration is necessary to
promote gelation of PBTA / PLA blend.
The elongation at break of blend films was measured andshowed PLA has improved point of hard but brittle at room
temperature. As a result, elongation of crosslinked PLA
with 5 phr TAIC EB-irradiated at 50 kGy was about 3 %,that crosslinked PBTA / PLA (8/2) blend with 5 phr TAIC
increased approximately 300 %. Furthermore, the blend film
was found to keep the shape by heating at 170 ºC. The
brittleness and heat-resistance of PLA were improved by theblending with PBTA and the radiation crosslinking withaddition of TAIC.
References
1) H. Mitomo, A. Kaneda, T. M. Quynh, N. Nagasawa, F.
Yoshii, Polymer, 46(3), 4695 (2005)
2) N. Nagasawa, A. Kaneda, S. Kanazawa, T. Yagi, H.
Mitomo, F. Yoshii, M. Tamada, Nucl. Instrum.
Methods Phys. Res., Sect. B, 236(1-4), 611 (2005)
100
Gel fraction (%)

Poly (lactic acid) (PLA) is a biodegradable polymer
produced by condensation polymerization of lactic acidobtained by fermentation of starch, which resources are
renewable. The variety of PLA applications include foodpackaging, bottles, medical and pharmaceutical products
result from very favorable properties of PLA such as hightransparency, strength, biodegradability, biocompatibility,and barrier properties. Nonetheless, the brittleness, lowdeformation at break and the lack of flexibility limit its
applications. Modification of PLA by blending withbiodegradable aromatic polyesters to improve its
mechanical properties has not been reported. The present
attempt was made to modify PLA by blending with anotherbiodegradable aromatic flexible polymer namelypoly(butylene terephthalate-co-adipate) (PBTA) shown infigure 1. Triallyl isocyanurate (TAIC) as a polyfunctionalmonomer has been found to be the most effective
crosslinking agent for PLA to improve heat-resistance in aprevious study.1,2) The effects of electron beam (EB)irradiation in the presence of TAIC on heat-resistant andmechanical properties of the blends was investigated.
PLA, PBTA and TAIC used in the experiments were
supplied as LACEA® H100 by Mitsui Chemicals Co., Japan,
Ecoflex® by BASF and by Nippon Kasei Chemical Co Ltd.,
Japan, respectively. The blends of polymers were mixed at
different ratios at 180 ºC for 10 minutes in a Laboplastomill
model 50C150 (Tokyo Seiki Ltd, Tokyo, Japan) at a rotor
speed of 60 rpm. TAIC was incorporated into the mixture
before mixing in the plastomill. The films from the blends
were hot-pressed at 180 ºC for 5 min and then cooled withrunning water to room temperature for 5 min to form a filmwith thickness of 0.5 mm. The films were enclosed inradiation resistant polyethylene / nylon bags and vacuum
sealed before irradiation at different doses from 20 kGy up

80
60
0phr
1phr
3phr
5phr

40
20
0

TAIC

0

20

40

60

80

100

Amount of PLA(%)

PBTA
Fig. 1 Structure of PLA, PBTA and TAIC

Fig. 2 Crosslinking behavior of PBTA / PLA blend
films, which involve different TAIC amount, formed by
EB-irradiation at 50 kGy.

－ 49 －

JAEA-Review 2007-060

2-16 Modification of Elastic Poly(lactic acid) by
Radiation-induced Crosslinking
S. Kanazawa a), N. Nagasawa b), T. Yagi b) , T. Hayasaki a) and M. Tamada b)a)b)

Sumitomo Electric Fine Polymer Inc., Environment and Industrial Materials Research
Division, QuBS, JAEA

Amount of plasticizer (%)

Poly(lactic acid), PLA was irradiated using electron beams in the presence of triallyl isocyanurate at 5 phr concentration as
crosslinking agent. The crosslinked PLA, of which heat resistance was improved, is applied on flexible and elastic materials
by addition of plasticizer or immersion in plasticizer. The elastic PLA material has several advantages such as high holding
plasticizer, heat resistance at 80 ºC and transparency. It can be concluded that crosslinking technology is beneficial toexpanding application of soften PLA.
.
たポア構造となっており、可塑剤はこのポリ乳酸のポ
植物原料由来のポリ乳酸は、地球温暖化防止の観点
ア中に含有されていると考えられる。
から廃棄燃焼処理により大気中の二酸化炭素増加を招
本技術は、エラストマー様な弾力性の感触を有した
く石油由来プラスチックの代替材料として実用化検討
ポリ乳酸を開発しており、「ポリ乳酸は硬く脆い」とが進められている。しかし、ポリ乳酸は耐熱性・耐衝いう従来の一般認識を大きく変えるものであり、具体撃性等の点で汎用プラスチックに劣り、実用化の妨げ的な実用化についての検討を今後進める計画である。
になってきた。原子力機構では、多官能性モノマーであるトリアリルイソシアヌレート(TAIC)の添加と放射線照射によるポリ乳酸の橋かけに成功しており1)、そのReferences
1) H.Mitomo et al., Polymer, 46, 4695(2005)
耐熱性向上効果、形状記憶効果を利用した熱収縮材へ
2) N.Nagasawa et al., Nucl. Instr. and Meth. in Phys. Res., B,の適用等を住友電工FPとともに行ってきた2)。さらなる
235, 616(2005).
実用化検討の結果、放射線橋かけの可塑剤担持性向上
効果を応用した、弾性ポリ乳酸の開発に成功した。
50
三井化学社製ポリ乳酸（レイシア H-440）に融点以上の温度（180 ºC）で TAIC を 5 質量部添加して混練した
40
後、同温の熱プレス機にて 500 μm 厚のシートを作製した。電子線を 2 MeV、90 kGy 照射した後に、理研ビタ
30Type ofミン社製可塑剤リケマール PL-710 および PL-019 の液
20plasticizer
中に 120 ℃で２時間浸漬・膨潤させ、可塑剤担持量（可PL019
塑剤質量／全体質量×100）が各々40 ％、35 ％の「弾10PL710性ポリ乳酸」を得た。弾性ポリ乳酸の可塑剤維持性を0評価するために、80 ºC の恒温槽内に静置し、可塑剤の析出による重量減少の度合いを見た。さらに、可塑剤とポリ乳酸の複合化状態を見るために、透過電子顕微
鏡（TEM）による微細構造の観察を行った。
Figure 1 に 80 ºC 恒温槽内での重量変化を示す。放射線橋かけポリ乳酸は、30 ％を超える高い可塑剤担持状
態を 80 ºC で 15 日間に亘って維持した。これは、同じ可塑剤 30 ％を、加熱溶融したポリ乳酸に練り込んだ場
合には常温でも数時間後に多くが析出する事を考えると、極めて高い保持力である。
コントロールとして、①電子線を照射しないシート、②TAIC を配合しないシートを作製したが、①と②のいずれも、可塑剤への浸漬工程で可塑剤の浸潤が起こらず白色化した。白色化は膨潤工程の熱で再結晶化したものと考えられた。以上の結果から、ポリ乳酸において可塑剤を高率に担持した状態を達成・維持するためには放射線橋かけ技術は非常に有効な手段だと考えられる。
Figure 2 に開発品の TEM 写真を示す（ポリ乳酸は白部分、可塑剤は黒部分に相当）。橋かけポリ乳酸の形
態は 20 nm 程度のナノサイズの結晶凝集体を起点とし

0

100
200
300
400
Holding time at 80 ºC (h)Fig. 1 Amount of plasticizer in the crosslinked PLA by
EB-irradiation at 90 kGy as a function of holding
time at 80 ºC.

100nm
Fig. 2 TEM photograph of the crosslinked PLA with
35 % plasticizer. White area: PLA, Black area:
plasticizer (PL-710)－ 50 －

JAEA-Review 2007-060

2-17 Radiation Crosslinking of Poly(L-lactic acid) /Poly(D-lactic acid) Stereocomplex
a)

a)

b)

b)

T. M. Quynh , D. Nagai , N. Nagasawa , T. Yagi , M. Tamadab)and H. Mitomoa)a)Graduate School of Engineering, Gunma University,
Environment and Industrial Materials Research Division, QuBS, JAEAb)

Poly(L-lactic acid) (PLLA) is produced by condensation
polymerization of lactic acid obtained by fermentation of
starch, which resources are renewable. Therefore, PLLA is atypicalchemicallysynthesizedandsustainablebiodegradable thermoplastic, which is expected wide usage
in the near future replacing many non-biodegradable
engineering plastics. The applications of PLLA include foodpackaging, bottles, medical and pharmaceutical products
which require high thermal stability. The poly(D-lactic acid)[PDLA] and PLLA blend can co-crystallize to form
stereocomplex (sc-PLA), with melting point (220 ºC) that isabout 50 ºC higher than for both PLLA and PDLA.
Therefore, this blend was intensively studied as a potential
material with high heat stability1) and triallyl isocyanurate(TAIC) has been proved as an effective crosslinker for
PLLA2,3). In this study, the properties of crosslinked sc-PLA/ TAIC films by radiation with different content of TAIC
and radiation doses were investigated
The melt mixture of commercial PLLA and PDLA (Mw,
Mw/Mn was 9.98×104, 1.6 and 28×104 and 1.57,
respectively) were hot-pressed at 230 ºC for 5 min and thencooled to room temperature for 5 min to form a film withthickness of 0.5 mm. The films were EB irradiated at
different doses with the same dose rate of 10 kGy pass-1.
Gel fractions, thermal and mechanical properties ofcrosslinked sc-PLA films were measured by differential
scanning calorimetry (DSC), thermomechanical analyzer(TMA) and tensile measurements.
The crosslinking structures are formed in irradiatedsc-PLA films with TAIC. Gel fraction of the sc-PLA films
represented to the crosslinking density increased with TAIC
content and radiation dose. Gel fraction seems to saturate atdose higher than 30 kGy.

Fig. 1 TMA heating curves of crosslinked sc-PLA by
EB-irradiation at 50 kGy. a)sc-PLA, b)sc-PLA / 0.5 %TAIC, c)sc-PLA / 1 % TAIC, d)sc-PLA / 3 %TAIC,e)sc-PLA / 5 % TAIC

DSC measurements of crosslinked samples irradiated at
50 kGy show typical crosslinking in sc-PLA mixed withmore than 3 % TAIC. Neither crystallization peak nor
melting peak of homo crystals (crystals of PLLA, PDLA)
can be observed in DSC of sc-PLA / 3 % TAIC irradiated atdose higher than 30 kGy like non-irradiated sc-PLA film.
Figure 1 shows TMA data of the sc-PLA containing
different amount of TAIC and irradiated at 50 kGy.
Extension of all samples increases at 60 ºC with very small
extension rate to around 200 ºC, then sc-PLA and irradiatedsc-PLA films with TAIC below 1% quickly elongate andbreak. However, the crosslinked films containing more than
3 % TAIC withdrew the load at temperature over 250 ºC
with low extension.
Figure 2 shows the stress-strain curves of sc-PLA
containing 3 % TAIC irradiated at different doses. At low
radiation doses, the curves of irradiated samples are similar
to non-irradiated sample (curves (a)~(c)). At higher
radiation doses (above 30 kGy), the mechanical propertiesof crosslinked samples are considerable higher than that ofsc-PLA.
Our research proved that the crosslinking density
increased, crosslinking network became tighter resulted in ahigher young’s modulus. The crosslinked samples became
harder and more stable. The combination of stereocomplex
formation and radiation crosslinking caused significant
improvement of heat stability of PLA material.
References
1) Y. Ikada, et al., Macromolecules, 20:904(1987)
2) H. Mitomo, et al., Polymer, 46(3), 4695 (2005)
3) N. Nagasawa, et al., Nucl. Instrum.
4) Methods Phys. Res., Sect. B, 236(1-4), 611 (2005)

Fig. 2 Stress-strain curves of crosslinked sc-PLA with
3 % TAIC by EB-irradiation at various doses.
a)Unirradiated, b)10 kGy, c)20 kGy, d)30 kGy,e)50 kGy, f)100 kGy－ 51 －

JAEA-Review 2007-060

2-18 Novel Elastic Gel Derived from Plant-resource
and Its Utilization
M. Takigami a), N. Nagasawa b), H. Amada a), T. Yagi b),
N. Kasai b), F. Yoshii b,c) and M. Tamada b)a)b)

Gunma Industry Support Organization, Environment and Industrial Materials Researchc)Division, QuBS, JAEA, Industrial Collaboration Promotion Department, JAEA

Carboxymethylcellulose (CMC) gel was formed by addition of acid to CMC (CMC-acid gel). Gel fraction (weight ofinsoluble part/initial CMC weight) was calculated after removing uncrosslinked CMC by immersing the CMC-acid gel inwater. The amount of gel increased with acid concentration. Mechanism of CMC-acid gel formation was elucidated byaggregation of CMC molecules as a result of replacement of sodium in carboxyl group with hydrogen. Gels could be
prepared by three different procedures; (1) mixing of CMC and acid, (2) immersion of CMC or γ-irradiated CMC pastes inacid, and (3) γ-irradiation of CMC-acid gel. Gels with different elasticity and hardness were prepared by changing degree ofsubstitution of CMC, molar mass of CMC, type of acid, concentrations of acid and CMC, and application of γ-irradiation.
カルボキシメチルセルロース(CMC)1)、カルボキシメ
チルデンプン2)、カルボキシメチルキトサン3)等の水溶性多糖誘導体が 10 ％以上のペースト状態で放射線橋
かけし、水に不溶な化学ゲルに調製でき、乾燥ゲル 1 g
で水を約 100～400 倍吸水する高分子吸収体になることを見出している。この技術を基に地域産学官が連携して申請した群馬県地域結集型共同研究開発プログラム「環境に調和した地域産業創出プログラム」において、
平成 18 年 1 月から放射線橋かけしたセルロースゲルによる家畜廃棄物処理に関する研究を進めている。
この研究を通して、ペースト状の CMC に放射線照射と酸への浸漬処理を組み合わせることにより、これまで作製できなかった弾力性を付与した CMC ゲルを作製できることを初めて見出した。CMC 弾性ゲルは、①CMC のペーストに放射線を照射後に酸水溶液中に浸漬する、②CMC と酸水溶液とを混練する、③上記②に γ 線照射するといった 3 つの方法で調整することが可能である。CMC の濃度、酸の種類や濃度を変化させることにより、様々な硬さを有するゲルを作製できることから、様々な用途に応用可能である。
ダイセル化学工業社製の CMC（置換度：1.36）と蒸留
水とを脱泡式ミキサーで混練した。混練した CMC ペー
ストをポリエチレン／ナイロンバックに入れ、脱気後、室温で γ 線照射し、酸処理を行った。作製した CMC ゲ
ルを水に浸漬し、橋かけしていない CMC を除去し、ゲル分率（不溶化した CMC の割合）および吸水量（CMC
ゲル 1g が吸収した水の重量）を算出した。CMC ゲルの力学的な物性として圧縮弾性率を測定した。また、
ゲル構造変化について、フーリエ変換赤外吸収（FT-IR）
測定及びエネルギー分散型蛍光Ｘ線分析装置（EDX）
測定で評価した。
CMC の濃度 20 %で作製したペーストに γ 線を照射し、1M の塩酸、リン酸、クエン酸水溶液に 4 日間浸漬した
ときのゲル分率の変化を調べた結果、強酸である塩酸とリン酸では、放射線橋かけした CMC でも、未橋かけの CMC でも、ゲル分率が 80 %になる事が分かった。
弱酸性の有機酸であるクエン酸では、線量の増加とともに、ゲル化が促進された。また、塩酸の濃度によるゲル化促進効果を調べた結果、放射線橋かけした CMC

ゲルに対して 0.1 M 以上の濃度でゲル化を促進し、未橋かけの CMC ペーストでも 0.5 M 以上の濃度があれば、ゲル化が促進した。これらのことから酸処理によって放射線橋かけ CMC ゲルのゲル化を促進することがわかった。放射線橋かけ CMC ゲルは、乾燥ゲル 1g に対して約 400 倍吸水するが、脆く壊れやすい性質を有する。しかし、酸処理すると吸水性が約 10 倍程度に低下するが、壊れにくく弾性を有する。そこで、放射線橋
かけゲルと酸処理したゲルの圧縮弾性率を測定した結果、放射線橋かけゲルは 50%圧縮すると壊れてしまう
が、酸処理したゲルは圧縮しても壊れず、荷重を外すと元の形状に戻ることがわかった。また、塩酸の濃度が濃くなるにつれ、50 %圧縮時の最大応力が増加した。
酸処理は、未橋かけCMCペースト又は放射線橋かけしたCMCゲルに弾性を付与できることから、フーリエ変換赤外吸収（FT-IR）測定及びエネルギー分散型蛍光Ｘ線分析装置（EDX）測定の結果よりゲル形成メカニ
ズムを考察した。20 %濃度のCMCペーストにγ線を 10
kGy照射したゲルと塩酸（0.5 M）で処理したゲルのFT-IRスペクトルを比較すると、処理前のカルボキシラ
ートイオンに起因する 1600 cm-1の吸収が、酸処理後、C=O伸縮に起因する 1730 cm-1の吸収に変化した。EDX
測定では、放射線橋かけゲル中のNa濃度が 8.79 wt %であったが、0.5 M塩酸で処理すると 3.22 wt%に減少することが分かった。これらの結果から、CMCゲルを酸で処理することにより、CMCのカルボキシル基の対イオンとして存在していたNaがHに置き換わり、カルボキシル基の解離が押さえられ、CMC分子鎖内あるいは分子鎖間の静電的反発が減少して、CMC分子鎖が凝集すると考えられる。硬くて脆いという従来の放射線橋かけCMCゲルに弾性を付与でき、広範囲での応用が期待され、具体的な実用化について検討を進めている。
References
1) B. Fel, et al., J. Appl. Polym. Sci., 78, 278(2000).
2) N. Nagasawa, et al., Carbohydr. Polym., 58(2), 109-113(2004)
3) L. Zhao, et al., Carbohydr. Polym., 51, 169-175 (2003)－ 52 －

JAEA-Review 2007-060

2-19 Preliminary Study on the Suitability of Carboxymethylated
κ-Carrageenan for Radiation Crosslinking
C. T. Aranilla
a)

a)

b)

, N. Nagasawa , A. Dela Rosaa)and M. Tamadab)b)Philippines Nuclear Research Institute, Environment and Industrial Materials Research
Division, QuBS, JAEA
exhibited by aqueous solutions at 10-20 % concentration.
The highest gel content reached 39 % at 100 kGy for the
40 % aqueous solution. Concentration effect on crosslinking
dose was also evident from the graph. Increase inconcentration resulted in decrease of crosslinking dose. A
gel fraction of about 30% was attained at 30 kGy for 40 %of CMkC aqueous solution, while the same gel fraction at
50 kGy for 30 %. These gels were immersed in distilledwater for 48 hours to estimate swelling ratio. The swelling
capacity of hydrogels decreased with increase in dose, as
well as with increase in polymer concentration. This canbe attributed to dependence of swelling on crosslink
densities of the hydrogels.
References
1) Silva, D. A.,et al., Carbohydr. Polym., 58, 163 (2004).
2) F. Yoshii, et al., Nucl. Instrum. Methods Phys. Res., Sect.
B. 208, 320 (2003).
3) Velde van de, F., Biopolymers. 6, 245 (2002).

50
40%

40

Gel Fraction, %Many polysaccharide derivatives have been prepared bycarboxymethylation reactions in order to increase the rangeof potential applications of these natural polymers1).
Recently, it was established that carboxymethylated
polysaccharides such as carboxymethyl cellulose,
carboxymethyl
starch, carboxymethyl
chitin andcarboxymethyl
chitosan,predominantly
undergocrosslinking reactions when are irradiated as highly
concentrated aqueous solution in paste-like state2).
κ-Carrageenan is a sulfated anionic polymer consisted ofalternating units of galactose and 3,6-anhydrogalactose3).
κ-Carrageenan is one type of carrageenan that is capable offorming thermo-reversible gels, however it typicallyundergoes chain scission reactions when is exposed tohigh-energy radiation. This study attempts for the first timeto synthesize carboxymethylated κ-carrageenan (CMkC)
and determines its suitability for radiation crosslinking.
κ-Carrageenan was slurried in isopropyl alcohol / water(80/20) and alkali-activated using 40 % aqueous NaOH at
40 ºC. After 1 h, monochloroacetic acid was added andallowed to react for 3 h. Carboxymethylation was confirmed
by degree of substitution (DS), Fourier transform infrared
spectroscopy (FTIR) and 13C nuclear magnetic resonanceanalysis (NMR). For crosslinking experiments, concentrated
aqueous solutions of carboxymethyl κ-carrageenan wereprepared using a hybrid mixer to obtain 10-40 % (w/w) inpaste-form. The samples were packed and vacuum-sealed inpolyethylene / nylon bags. Gamma irradiation was
conducted in 60Co facility until dose of 100 kGy, in air andambient temperature. Crosslinking was assessed in terms ofgel fraction.
DS of obtained carboxymethyl κ-carrageenan derivative
measured by potentiometric back-titration was 1.20. FromFTIR analysis peaks due to －COO- and －CH2 vibrationsof the carboxymethyl group were observed. 13C NMR
analysis revealed the occurrence of carboxymethylation in
the three hydroxyl groups of κ-carrageenan disaccharide
unit.
Crosslinking of carboxymethyl κ-carrageenan was
successfully done and proved to be promising as shown in
Fig. 1. The samples irradiated at different concentrations
exhibited different degrees of crosslinking as a function ofdose. Gel fractions were obtained for CMkC aqueous
solution at 30-40 % concentration while no gel content was

30%
30

20

10
20%
10%

0
0

25

50

75

100

125

Dose, kGy
Fig.1 Gel fraction of carboxymethyl κ-carrageenanhydrogels as a function of dose. The DS of carboxymethyl
κ-carrageenan is 1.20.

－ 53 －

JAEA-Review 2007-060

2-20 Effect of Radiation Crosslinking on Stabilityof Bent Polyethylene Pipea)N. Kasai , F. Yoshii

a)and J. Yuasab)a)Environment and Industrial Materials Research Division, QuBS, JAEAb)
Sekisui Chemical Co.Ltd

Recently polyethylene (PE) has been widely used forwater and sewage pipes because of its high strength andcorrosion resistivity. Bent PE pipes, which are necessary toconstruct pipe lines, are usually produced by bending ofstraight pipes at high temperatures around the melting pointof PE. When such bent pipes are used for long time , change
in the bending angle takes place, which is regarded as aserious problem. In this article, the effects of radiation
crosslinking on the stability of bent PE pipes areinvestigated.
Electron irradiation was carried out at 2MV, 2mA with adose rate of 10 kGy/pass to induce crosslinking structure forstraight high density PE pipes with 60 mm diameter(thickness 5.5 mm). The PE pipes were irradiated on bothsides at doses of 30 – 100 kGy. γ-ray irradiation was done
for high density PE pipes with 180 mm diameter (thickness
16.4 mm) at 80 kGy with a dose rate of 10 kGy/hr.
After irradiation, straight PE pipes heated at around themelting point were set in form to bend at the angle 90° forgiven time and cooled down to form bent PE pipes. The
angle of fabricated PE pipes was measured with on angle
meter and the appearance of the pipe surface after bendingat high temperatures was also examined.
Figure 1 shows changes of the angle of PE pipes bent at

96.0

100kGy

104.0
102.0
100.0

94.0
Angle of Bend （°）

108.0
106.0
Angle of bend （°）

135℃ after electron irradiation in a dose range of 30 – 100
kGy . For the PE pipes irradiated at 50 kGy and 80 kGy,change in the angle is small, 2 – 3°, while irradiation of PE
pipe at 30 kGy and 100 kGy gives large deviations. No
significant change in the surface morphology was observed
between irradiated PE pipes and the original sample (before
irradiation). Small angle deviations within 3° are desired in
the practical application of bent PE pipes. Thus, electron
irradiation at 50 – 80 kGy is preferable to fabricate stablebent pipes. As an acceleration test, the stability of bent PE
pipes was examined at 60℃ for 24 hrs, the results of PE
pipes γ-irradiated at 80 kGy are shown in Figure 2.
Irradiated pipes exhibit smaller change in the angle than thatof the unirradiated one. PE pipes bent at above the melting
point, 133℃ after irradiation indicate small deviation of
only 2°. Moreover, the appearance of the PE pipe surface
after bending at high temperatures was investigated. PE
pipes bent at 133° for partial melting were rough incomparison with that bent at 126℃. From these findings, it
can be concluded that crosslinking is effective to improve
the stability of PE pipes bent at high temperatures aroundthe melting point of PE.

30kGy
50kGy

98.0
96.0
94.0

80kGy

92.0
90.0

92.0
90.0
88.0

non irradiation： 126℃

86.0

non irradiation： 133℃

84.0

80ｋGy： 126℃

82.0

80ｋGy： 133℃

80.0

0

2

4

6

8

Time from bending (day)Fig. 1 Change in the angle of PE pipes bent at 135°
after electron irradiation at 30,50,80 and 100kGy.

－ 54 －

Angle befor test
0Angle after bending
1
2
Condition

60℃、24h3

Fig. 2 Change in the angle of γ- irradiated PE
pipes when they were kept at 60℃.

4

JAEA-Review 2007-060

2-21 Development of Decomposition Technology for
Formaldehyde in Air by Electron Beam
A. Shimada and K. Hirota
Environment and Industrial Materials Research Division, QuBS, JAEA,
The sterilization of clean rooms has been performed
using a mixture of formalin/air generated by thevaporization of a commercially available formalinsolution containing about 37 % formaldehyde (HCHO)and 5-10% methanol (CH3OH). The mixture in clean
rooms needs to be treated after sterilization. For instance,
in some food packaging factories, sterilization gas istreated by circulating through heat-catalyst reactor. It
takes 2 or 3 days to complete the treatment. To improve
the productivity of such factories, the development ofeffective treatment methods is strongly required. Electron
beam is expected to be one of the alternative methods fortreating organic pollutants because they can effectively beoxidized by active species (OH, O, N, O3 and so on)
generated in air by electron beam irradiation. In theprevious study, we estimated that formalin/air mixture (airwith HCHO and CH3OH) at the HCHO concentration of1200 ppmv in a clean room of 2000 m3 can be treated byelectron beam within about half of a day1). In this study,
HCHO/air mixture (air with HCHO, without CH3OH) isirradiated to examine the decomposition process of
HCHO.
Air mixture containing 100-1060 ppmv HCHO and
1 % water were irradiated with electron beams at
absorbed doses of 5-80 kGys. The change in theconcentration of HCHO as a function of dose is shown in
Fig.1. The concentration decreased exponentially withdose. From the initial slope of the curves in Fig.1, thedecrease in the HCHO concentration per 1 kGy wasestimated to be 19, 35, 50, 64 ppmv / kGy for 100, 280,
480, 1060 ppmv of HCHO, respectively. These values aremuch larger than that of OH radical generated by electron
beam, i.e., 10 ppmv / kGy. These results can be explainedin terms that HCHO is decomposed by a chain reaction.
The irradiation of HCHO produced HCOOH, CO, andCO2, as shown in Fig.2. Almost all decomposition
products in the irradiation of HCHO were identified. The
concentrations of CO and CO2 gradually increased in adose range of 2.5-10 kGy. On the other hand, the increaseof the HCOOH concentration was suppressed above 5
kGy. It indicates that the active species like OH radicals
reacted with not only HCHO but also with HCOOH.
Carbon balances in the HCHO irradiation showed that
104, 93, and 95 % of reacted HCHO were recovered atabsorbed doses of 2.5, 5, and 10 kGy, respectively. It was
found that HCOOH, CO, and CO2 were main products in
the irradiation of HCHO.
Reference
1) Shimada, A.; Hakoda, T.; Kojima, T., J. Chem. Eng.
Jpn.,Vol.39, No.9 (2006)

600
HCHO

1060 ppmv
480 ppmv
280 ppmv
100 ppmv

1200
1000
800

Concentration / ppmv

Concentration / ppmv

1400

600
400
200
0

20

40

60

80

CO
CO2

300
HCOOH

0

Absorbed dose / kGy

5

10

Absorbed Dose / kGy

Fig.1 Concentration of HCHO in air mixture as a

Fig.2 Concentration of HCHO and irradiation products asfunction of dosea function of dose－ 55 －

JAEA-Review 2007-060

2-22 Development of PCDD/Fs Treatment Technology by
Gamma-ray Irradiation
K. Hirota and C. Zhao
Environmental and Industrial Materials Research Division, QuBS, JAEA

Decomposition rate (%)

dechlorination,100
namelythe
80
Ethanoldissociation ofTolueneCl-substituentsｎ-Nonane60
on the aromaticrings of dioxin,40leading to form
lower
20
chlorinatedcongeners such0
as hepta- and
0
50
100
150
200
Absorbed dose (kGy)hexachlorodibe
Fig.2 Decomposition of PCDD in
nzo-p-dioxin
solvents by gamma-rays(HpCDD and
HxCDD). Thus, the decomposition behavior forchlorodibenzo-p-dioxin having from zero to eightCl-substituents (PCDDs) was investigated and the result isshown in Fig.2. The decomposition rate for PCDDs was quit
lower than that for OCDD, indicating that OCDD wasdechlorinated to from lower chlorinated congeners throughreactions with the solvated electrons. Although thedecomposition rate for OCDD in n-nonane was higher thanthat for toluene, PCDD in n-nonane was less decomposedcompared to PCDD in toluene. To clarify the phenomena,
the dechlorination profile of OCDD was examined andfound that 80 % and 20-30 % of reacted OCDD were
dechlorinated in n-nonane and toluene, respectively. These
values did not much change up to 160 kGy. The
concentration of HpCDD formed by the dechlorination of
OCDD increased in n-nonane with an absorbed dose, while
reached a maximum in toluene at a dose of 50 kGy.
Dechlorination is a dominant reaction for the treatment ofdioxin in n-nonane. Dioxin is mainly oxidized in toluene
solvent5). It was found that ethanol is a good solvent fortreating dioxin using an ionizing radiation.
Decomposition rate(%)

1. Introduction
The emission of dioxins to the environment was about
330 g-TEQ/yr in 2005, which was decreased by 90%
compared to those in 19991). On the other hand, the amountof dioxin in analytical wastes has risen in laboratory due to ahigh demand on dioxin analysis. It can be much burden to
store the wastes as similar to Polychlorinated biphenyl(PCB) in Japan. PCB has been treated by incineration,
dechlorination, and hydrothermal oxidation etc at five
facilities in Japan2). However, to construct sort of facilities
requires residence’s agreement and corporation, and iscostly. Ionizing radiation technology is expected to be oneof the economical methods for treating the dioxin wastes
because we can use existing irradiation facilities without
additional equipments. It can treat the wastes with a simple
process. No additive or temperature control is required.
Nuclear waste can also use as radiation source.
2. Experiments
Experiments on the treatment of dioxin wastes werecarried out using octachlorodibenzo-p-dioxin (OCDD)(Cambridge Isotope Laboratory, Inc.) because it can behandled with lower toxicity and purchased as a crystal. The
samples prepared in toluene, n-nonane, and ethanol solvents(Wako Pure Chemical Industries, Ltd.) were irradiated withgamma-ray at a dose rate of 10 kGy/h. The concentration of
OCDD/F and other isomers were measured before and after
irradiation using GC/HRMS (JEOL JMS-700).
3. Results and Discussion
Decomposition profile for OCDD in the three solvents isshown in Fig 1. The decomposition rate of OCDD in thethree solvents increased with an absorbed dose. The highest
rate was obtained from OCDD in ethanol, followed by innonane and in toluene. This decomposition order isessentially same as G-value for the formation of solvatedelectron in the three solvents (ethanol:1.7, n-nonane: 0.12,
toluene: 0.09)3,100
4). This suggests
thatsolvated
80
electronis60
associated withtheEthanol40
decompositionn-Nonaneof PCDD. The
Toluene20
reactionsofsolvated
0electrons with
0
50
100
150
200
dioxinsareAbsorbed dose (kGy)based on the Fig.1 Decomposition of OCDD insolvents by gamma-rays
reduction
byReferences
1) Ministry of the Environment. Dioxin Emission Inventory.
http://www.env.go.jp/press/press.php?serial=7782(inJapanese).
2) JESCO. Project for the Treatment of PCB Wastes
http://www.jesconet.co.jp/business/index.html (in Japanese).
3) Spinks, J. W. T., Woods, R. J. W.: An Introduction to
Radiation Chemistry, 3rd ed.; John Wiley & Sons: New
York, 1990.
4) Sun, G. S., Qin, X., Fang, X., and Wang, W. Radiat, Phys.
Chem., 55 (1999) 409.
5) Zhao, C., Hirota, K., Taguchi, M., Takigami, M., andKojima, T. Radiat. Phys. Chem. 76 (2007) 37.

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JAEA-Review 2007-060

2-23 Study on the Treatment of Endocrine Disrupting
Chemicals in Wastewater by Ionizing Radiation
A. Kimura

a)

a)

b)

c)

d)

, M. Taguchi , Y. Ohtani , H. Hiratsuka , T. Kojima

a)and K. Hirotaa)b)Environment and Industrial Materials Research Division, QuBS, JAEA, Gunmac)
Prefectual Institute of Public Health and Environmental Sciences, Gunma University,d)Department of Advanced Radiation Technology, TARRI, JAEA
3. Results and Discussion
E2 in the model wastewater was decreased as a functionof dose as shown in Fig. 1. The reduction rate of E2
concentration decreased with an increase in the amount of
TOC. Coexistents should influence to the decomposition of
E2. The same inclination was obtained for thedecomposition of NPs in the model wastewater.
The change in estrogen activity of the real wastewaters by
γ-ray irradiation is shown in Fig. 2. The curves of estrogen
activity have a maximum, indicating that estrogen active
products were formed in the decomposition process. To
eliminate the endocrine disrupting property against thehuman body requires an expose to the samples at about 200
Gy to reach the estrogen activity less than 1 ng dm-3. Since
E2 at an estrogen activity of 500 ng dm-3 in pure water was
decomposed at a dose of 50 Gy, the requirement of higher
doses for the decomposition of EDCs in the real
wastewaters was due to the consumption of OH radicals
through reactions with coexisting organic substances having
no estrogen activities.
The initial investment for electron-beam system wasfound to be 15 yen m-3 to treat secondary effluent in sewage
treatment plants with a capacity of 10,000 m3 day-1 on thebasis of 15-years operation. The consumption of electricity
for an operation of the electron accelerator is estimated to be
2 yen m-3. Ionizing radiation is expected to be one of thepromising methods for treating EDCs in water1).

1. Introduction
Endocrine disrupting chemicals (EDCs) in theenvironmental water give serious influence to aquatic
animals such as mimicking the estrogen and disrupting theendocrine system in living bodies. This study is to give thevalidity of ionizing radiation for the treatment of trace
amounts of EDCs in the environmental water.
Decomposition of 17 β-estradiol (E2) and p-nonylphenols(NPs) in aqueous solution were studied using 60Co γ-ray
because they have higher estrogen activities in theenvironmental water. Real wastewaters containing some
EDCs were also irradiated. The cost for the treatment ofwastewater containing EDCs by ionizing radiation was
estimated based on the experimental results obtained inpresent studies.
2. Experimental
Real wastewater samples were obtained from secondary
effluents downstream from the activate sludge system inwater treatment plants. Model wastewater samples wereprepared by adding E2 at 1.8 nmol dm-3 or NPs at 20 μmol
dm-3 to wastewater having no estrogen activity. The samples
were irradiated with γ-rays at 298 K. The concentrations of
the EDCs with biological activities in the samples were
measured before and after irradiation by chemical analyses
and biological assays. Estrogen receptors of human andmedaka were used for the yeast two hybrid assay to estimate
estrogen activities, which are hereinafter defined as hEA
and mEA, respectively.

15

TOC 20.3 × 10-3 g dm-3
TOC 10.2 × 10-3 g dm-3
TOC 1.02 × 10-3 g dm-3
TOC 4 × 10-6 g dm-3

1

(a)

mEA
hEA

Estrogen activity / ng dm-3

Estrogen acitivity / ng dm-3

15

10

5

0

0

50

100

150

Dose / Gy

(b)

mEA
hEA

10

5

0

0

50
100
Dose / Gy

150

20

0
0

100
Dose (Gy)200

Fig. 1 Concentration of E2 in model wastewater at each
TOC concentration as a function of dose.

Estrogen activity / ng dm-3

Concentration (mol dm-3)[ × 10-9] 2

Reference
1) A. Kimura et al., Radiat. Phys. Chem., 76, 699-706(2007).

(c)

mEA
hEA

10

0

0

－ 57 －

50
100
Dose / Gy

150

Fig.2 Change in estrogen
activity of real wastewatersby γ-ray irradiation.
(a) Sample 1(b) Sample 2(c) Sample 3

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JAEA-Review 2007-060

3-01 Detection of Ion-beam-induced Mutations Using Positive
Selection Marker Genes in Arabidopsis
Y. Hase, R. Yoshihara, Y. Yokota and I. Narumi
Radiation-Applied Biology Division, QuBS, JAEAThe extensive analyses using model plant Arabidopsis
showed that the ion beams have higher mutagenic effects
compared to low-LET radiations1). It was also shown thatthe ion beams frequently induce deletion-type mutations2).
Furthermore, application of the ion beams for mutation
breeding demonstrated that the ion beams have wide
mutation spectrum and that the ion beams can induce
mutants without undesirable defects3). However, there arestill unsolved points in mutagenic effects of ion beams, thatis, (1) relationship between the property of ion beams andthe mutation frequency or spectrum, (2) relationshipbetween the material tissue type and the mutagenic effect,and (3) mechanism for why the recessive homozygous-likemutants, such as chlorophyll deficient mutants, wereobtained in the irradiated generation. In order to clarify
these points, we are analyzing the mutagenic effects of ion
beams using positive selection marker genes as described
below. In this year, we prepared the transgenic plantmaterials and determined the radiation sensitivity of them tothe ion beams and gamma rays.

Fig. 1 Selection of transgenic codA plants on
5-FC-supplemented medium. T2 plants obtained by aself-pollination of transgenic plants heterozygous for codA
gene were grown on 5-FC medium. codA plants (sensitive)
and wild-type (resistant) plants were segregated in a ratioof 3 : 1.

ribosomal protein S12 (rpsL)
The rpsL gene that encodes ribosomal S12 protein
confers streptomycin-sensitive phenotype when it istransformed into Escherichia coli. Based on the plasmid
rescue method, we can detect only the mutated genes as
streptomycin-resistant colonies4). Since this method can
detect large number of somatic mutations in a short time, wewill analyze the mutagenic effects of ion beams with theemphasis on the difference of material tissue types.
cytosine deaminase (codA)
The codA geneproduct of E.coli deaminates
5-fluorocytosine (5-FC) into 5-fluorouracil (5-FU). Since
5-FU leads to depletion of dTTP for DNA synthesis, theplants having codA gene can not grow on a selection
medium supplemented with 5-FC5) (Fig. 1). The wild type
Arabidopsis ecotype Columbia was transformed with codA
gene under the control of CaMV 35S promoter. We haveselected T3 plants that are homozygous for codA gene basedon the segregation ratio on 5-FC medium. This method canbe thought to detect any types of heritable mutations
including large deletions.
We have determined the sensitivity of the seeds oftransgenic plants for carbon ions and gamma rays (Fig. 2).
The shoulder dose was 930 Gy for gamma rays, 240 Gy for
320-MeV carbon ions, and 180 Gy for 220-MeV carbon
ions.

Fig. 2 Survival curves for the seeds of rpsL transgenic
plants exposed to ion beams and gamma rays.

References
1) N. Shikazono et al., Genetics 163 (2003) 1449.
2) N. Shikazono et al., Genetics 157 (2001) 379.
3) M. Okamura et al., Nuc. Instr.Meth. B 206 (2003) 574.
4) J. Stougaard, Plant J. (1993) 755.
5) R. Yoshihara et al., Radiat. Res. 47 (2006) 223.

－ 67 －

JAEA-Review 2007-060

3-02 Mutation Induction in Orchids Using Ion Beams
a)

a)

a)

a)

b)

A. H. Affrida , A. Sakinah , A. Zaiton , B. Mohd Nazir , A. Tanaka ,b)b)b)
I. Narumi , Y. Oono and Y. Hasea)

Agrotechnology and Biosciences Division, Malaysian Nuclear Agency,b)
Radiation-Applied Biology Division, QuBS, JAEA

Orchid is the main export for Malaysia’s floricultureindustry. Due to the increasing demand for orchid pot plants
and cut flowers, new commercial varieties with new
characteristics such as colour, shape and longer shelf life offlower are needed. The use of hybridization for orchid
breeding is restricted by sexual incompatibility, sterility
problems and long breeding time. Mutation induction by ion
beam provides an alternative for improvement of orchids. In
this study, we tried to produce mutants with new flower
colour, shape and shelf life.
The protocorm-like bodies (PLBs) of two orchid species;
Dendrobium mirbellianum and Dendrobium crumenatum
were placed on 6-cm sterile petri dishes containing half
strength MS (Murashige & Skoog, 1962) media. The
samples covered with a Kapton film (8-µm-thick polyimidefilm) were irradiated with 320 MeV 12C6+ ion beams atvarious doses ranging from 0 to 12.0 Gy1) from the TIARA
AVF cyclotron (JAEA, Takasaki). After irradiation, cultures
were subcultured on to fresh ½ MS media every 4 weeks for
multiplication and regeneration. The number of regenerated
shoots from each dose was recorded after 2 months.
Mutation effects of carbon ions on both species wereobserved at tissue culture stage. In D. mirbellianum,
chlorophyll mutation was detected in one of cultures
irradiated at 0.4 Gy (Figure 1). The PLBs from which theseplantlets originated were subcultured to obtain more of themutants. Attempt has been made to harden one of thesemutant plantlets but it could not survive the glasshousecondition. The plantlets were grown for a longer period intissue culture environment to increase the chance of survival
during hardening.
More tissue culture plantlets were transferred from time
to time to the glasshouse for screening. Plantlets of D.
mirbellianum are growing very slow and have not reachedflowering stage.

Meanwhile, variations were also observed in some of D.
crumenatum cultures. Some of the variations are shown in
Figure 2. In Figure 2a, 2b and 2c are culture irradiated at 2
Gy. Figure 2a shows variations in leaf shape whileelongation of stem is shown in Figure 2b. The rest of 2 Gy
cultures look as a culture in Figure 2c. Slow growing culture
was observed in a 0.2 Gy population (Figure 2d). The
control is as shown in Figure 2e.
Differently from D. mirbellianum, D. crumenatum plants
have started to flowering. The length of blooming period
was recorded. This is for comparison with the control that
only blooms for one day. Data are still currently collected.
However, no morphological change in terms of flower
colour and shape was observed.
Tissue culture seedlings were constantly transferred to theglasshouse to screen for color variation in the growing
plants.

Fig.2 Cultures of D. crumenatum which show someabnormalities compared to the control: a,b and c (2Gy), d (0.2 Gy), and e (control).
Fig.1 Chlorophyll mutation observed in
mirbellianum cultures irradiated at 0.4 Gy.

D.

Reference
1) B. Mohd Nazir et al., TIARA Ann. Rep. (2005) 45.

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JAEA-Review 2007-060

3-03 Tobacco BY-2 Cells Have a Transient and Leaky
DNA-Damage Checkpoint at G2/M Phase after
Gamma-ray Irradiation
a)

a)

b)

a)

a)

c)

Y. Yokota , T. Funayama , S. Wada , Y. Hase , Y. Kobayashi , M. Inoue ,a)a)A. Tanaka and I. Narumia)b)

Radiation-Applied Biology Division, QuBS, JAEA, Department of Veterinary Medicine,c)Kitasato University, Graduate School of Agriculture, Kyoto Prefectural University

Many types of higher plants including herbaceous plants
show high radiation-tolerance at both levels of individualand cell 1), however the tolerance mechanism is unclear inlarge part. By quantifying the initial yields and the repair
kinetics of DNA double-strand breaks (DSBs), we foundthat tobacco BY-2 protoplasts can tolerate 5-times more
DSBs per cell than Chinese hamster ovary CHO-K1 cells 2)
although they have a similar efficiency of DSB repair.
In this study, we analyzed cell cycle phase distribution byflow cytometry and measured micronucleus (MN) induction
rate in tobacco BY-2 cells irradiated with gamma rays.
As a result, the fraction of G2/M-phase of the cells
irradiated with 40-Gy gamma rays was more than that of theunirradiated cells at 24 h of post-irradiation culture, and thedifference was disappeared at 48 h (Fig. 1). This result
indicates that the DNA damage checkpoint of BY-2 cells
transiently functions at G2/M phase. Additionally, thepercentages of the cells having at least one MN were greater

24 h

40 Gy gamma-rays
0h
24 h

References
1) Y. Yokota et al., Int. J. Radiat. Biol. 79 (2003) 681.
2) Y. Yokota et al., Radiat. Res. 163 (2005) 520.

48 h

Cells having at least one MN (%)

No. of nucleus

0 Gy control
0h

in irradiated cells than in unirradiated cells (Fig. 2),
suggesting that the DNA damage checkpoint of BY-2 cells isleaky. In the irradiated cells, the percentage of the cells
having at least one MN peaked at 48 h after irradiation andthereafter decreased over time. This is because MN is
induced through at least one cell division after irradiation,and the MN induction rate per division decreases gradually.
This unstable genome maintenance seems to be
unreasonable for organism at first glance, but may be
admissible for life style of higher plants: most of them mustgrow quickly within a limited life span for acquiring
sunlight more than competitors, even if the genomes ofsomatic cells become unstable.

48 h

50
40
30
20
10
0

24
48
72
96
120
Time of post-irradiation culture (h)DNA content per nucleus
Fig. 1 Analysis of cell cycle phase distribution after
gamma-ray irradiation in tobacco BY-2 cells. In eachhistogram, the time of post-irradiation culture wasshown, and the left and right peaks and the area
between their peaks indicate G0/G1-, G2/M- andS-phase cells respectively.

Fig. 2 Percentage of tobacco BY-2 cells having atleast one MN after gamma-ray irradiation of 40 Gy(closed circle) or 0 Gy (open circle).

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JAEA-Review 2007-060

3-04 Effect of Ion Beam Irradiation for Microspores ofEggplant ( Solanum melongena L.)
a)

a)

a)

a)

a)

Y. Saiki , K. Takata , Y. Uchimura , K. Hirashima , T. Nakahara ,b)b)b)
Y. Hase , Y. Yokota and A. Tanakaa)Department of Agricultural Biotechnology, Fukuoka Agricultural Research Center,b)
Radiation –Applied Biology Division, QuBS, JAEA

To get thornless eggplant, microspore of eggplant ‘AE-P11’ (Solanum melongena L.) were irradiated with 12C6+・320
MeV beams ranging from 0.5 to 20 Gy by AVF cyclotron in JAEA. The number of calli formed from irradiated microsporesdecreased with increasing dosage. The rate of them compared with non-irradiated treatment was 91 % at 0.5 Gy, 80 % at 1
Gy, 48 % at 2 Gy, 12 % at 5 Gy, 5 % at 10 Gy and 3 % at 20 Gy. At present about four hundred calli were formed from
irradiated microspores with various doses. Regenerants from the calli will be screened for thornless.
形成率は低下した。本実験の結果、単為結果性ナス系
統‘AE-P11’小胞子のカルス形成に対する 12C6+ ・320
MeVイオンビーム照射のLD20は1 Gy、LD50は2 Gy付
近であることが明らかとなった。
現在、12C6+・320 MeVイオンビームを0.5~20 Gy照
射した小胞子からカルスが約400個形成し、カルスから倍加半数体を再生中である。今後、これらの再生植物体について、トゲのない変異体を選抜する予定である。

100
Rate of callus formation (%)

ナスの萼や葉柄にあるトゲは、作業時の怪我や果実を損傷する問題があることから、トゲがない品種が望まれている。このため、小胞子培養とイオンビーム突然変異育種を組み合わせ、トゲのない変異体の早期作出を図った。
小胞子培養の利点は、半数性細胞であるため、得られた半数性変異体の染色体数を倍加することにより、照射当代で遺伝的に固定し、短期間で目的形質を備えた純系の選抜ができることである。
今回は、ナス系統‘AE-P11’ ( Solanum melongena L.)の変異体を効率的に作出するため、その小胞子へのイ
オンビーム照射線量がカルス形成率に及ぼす影響を調査した。
供試したナス系統‘AE-P11’は、独立行政法人、野菜茶業研究所が育成した単為結果性系統で、受粉作業を省力化できる有望な系統である。
小胞子の単離と調整は、高田ら 1) の方法を一部改変して、以下のように行った。すなわち、表面殺菌した
蕾から葯を取り出し、滅菌水を加えシリンジで押しつぶして、単離した。滅菌水中で35 ℃、3日間の高温処
理後、40 %と60 %パーコールの密度勾配遠心分離を行い、境界層の小胞子を回収した。回収した小胞子は、パーコールを滅菌水で洗浄後、0.4 mg/l 2,4-D、0.2 mg/l
BA、2 % sucrose、0.2 % ゲランガムを加えたNLN培地に、2×105 個/ml に調整した。その培地を、直径35mmシャーレに1 mlずつ分注して包埋し、カプトン膜で
覆った。
12 6+
C ・320 MeVイオンビームの小胞子への照射は、日本原子力研究開発機構イオンビーム照射研究施設（TIARA）のAVFサイクロトロンで行った。照射線量は0.5, 1, 2, 5, 10および20 Gyとした。照射後、試料に1mlのNLN液体培地を加え、25 ℃、暗黒条件下で培養し、4週間後にカルス形成数を調査した。
無照射でのカルス形成数に対する各照射線量のカルス形成率をFig.1に示した。照射線量0.5 Gyでは91 %、1 Gyで80 %、2 Gyで48 ％、5 Gyで12 ％、10 Gyで5 %、20 Gyで3 %と、照射線量が増加するに従って、カルス

80
60
40
20
0
0

5

10

15

20

Dose(Gy)

Fig.1 Effect of 12C6+・320 MeV ion beam on the callus
formation from microspores. The number of calli wascounted at 4 weeks after irradiation. The average of 3 petri
dishes at one experiment were expressed as a percent ofnon- irradiated control.

Reference
1) K.Takata, et al., TIARA annual report 2005 (2006) 48.

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JAEA-Review 2007-060

3-05 Development of Commercial Variety of
Osteospermum by a Stepwise Mutagenesis by Ion
Beam Irradiationa)a)

M. Iizuka , Y. Kimura , Y. Hasea)b)

and A. Tanakab)b)Gunma Agricultural Technology Center， Radiation-Applied Biology Division, QuBS, JAEA

Materials and methods(1) Preparation of re-irradiation material
Leaf sections (quadrilateral pieces with 0.5 to 1 cm insize) of the white variant OM7 of Osteospermum 'Mother
Symphony' were put on 1/2 MS medium supplemented with
0.1 mg/L NAA and 1.0 mg/L BA. After irradiation andpost-cultivation, the re-differentiated individuals wereobtained.
(2) Examination of irradiation conditions
Samples covered with Kapton films were irradiated with
320 MeV carbon ion beams (12C5+) at various doses (0 to 12
Gy).
(3) Selection of variants using the optimized dose
Leaf disc sections were irradiated with carbon ions (12C5+
and 12C6+) at a range of 0.1 to 5 Gy. After 24 hr, the leaf discsections were transferred to fresh 1/2 MS medium
supplemented with 0.1 mg/L NAA and 1.0 m /L BA to
induce adventitious buds. After about 1 month, grownadventitious buds were transplanted on fresh 1/2 MS
medium, and cultivated to obtain plantlets. The resultant
plantlets were acclimatized and then grown in a greenhouseto investigate flower color and morphological changes.
Results and Discussion
The leaf disc sections of re-irradiated variant OM7
exhibited higher sensitivity to ion beams than those of'Mother Symphony'. The adventive bud differentiation did
not occur in variant OM7 over 8 Gy of 12C5+ (Fig. 1). For
this reason, the optimized irradiation dose for the selectionof variants from OM7 was determined to be 0.1 to 5 Gy.
Up to now, several thousands of plantlets were grown, and
13 distinctive individuals were selected in terms of flower
color and morphology. Among them, color variations at
the upper side of petals included purple and pale orange.
On the other hand, color variations at the under side ofpetals included pale yellow and orange.
However,isochroous variant was not obtained in this experiment.
Other mutations in petals and stalks included dwarf,
multi-petals and petal deformations.
As mentioned above, the white petal variant OM7 wasderived from irradiated 'Mother Symphony' that originallyhas yellow petals. Second irradiation of OM7 resulted inacquisition of variants such as purple and multi-petals that
did not appear in first irradiation experiment, suggesting that
re-irradiation induced a stepwise mutation in pigment
synthesis and morphogenesis pathways.
100
2nd
1st

80
Regeneration rate (%)

Introduction
Osteospermum is one of the composite perennials, andcharacterized by a long flowering time. Recently, theproduction of Osteospermum has increased as potted plants
and flowerbed materials. Besides the ordinary mating, budmutation has been used for the breeding of new varieties.
However, the development of new and more efficientmutagenesis techniques with an artificial manner is expected
at production fields.
Previously, we irradiatedOsteospermum 'Mother Symphony' with ion beams, andselected 37 flower-color and morphological variants out ofapproximately 3,000 individuals1).
Among them, an
unprecedented pastel color variant was applied to the variety
registration as 'Vient Flamingo (tentative name)' in March20072). Besides, many petal color variants such as whiteand orange could be obtained from irradiated 'Mother
Symphony' that has yellow petals. Usually, Osteospermum
has different colors between the upper side and under sideof the petals. Interestingly, the irradiated variants included
orange- and yellow-isochroous variants. However, we
could not obtain a white-isochroous variant that has apotentially high market value. Therefore, in an effort toobtain a variant with white-isochroous petals, we irradiatedagain the white petal variant of 'Mother Symphony' with ion
beams.

60

40

20

0
0

2

4

6
8
Dose (Gy)1012Fig. 1 Sensitivity of Osteospermum to ion beams.
References
1) M. Iizuka et al., TIARA Ann. Rep. 2004 (2005) 50．
2) M. Iizuka et al., JAEA Takasaki Ann.Rep.2005 (2006) 81．

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JAEA-Review 2007-060

3-06 Comparison of the Mutation Inducing Effect between Ion
Beams and Gamma-rays - Guineagrass and Sorghuma)

b)

c)

d)

a)

H. Nakagawa , M. Inafuku , M. Kusaba , H. Yamaguchi , T. Morishita ,
a)
c)
e)
f)
f)
f)
R. Morita ,M. Nishimura , S. Hoeman , Y. Yokota , Y. Hase and A. Tanakaa)b)Institute of Radiation Breeding (IRB), NIAS, Okinawa Prefectural Livestock Research Center,d)e)University of Tokyo, National Institute of Floricultural Science, NAFSO, BATAN, Indonesia,f)Radiation-Applied Biology Division, QuBS, JAEA

c)

LD50 of NY is 600 – 800 Gy for γ rays and 40 – 50 Gy
with C ion beam irradiation. Figure 3 illustrates the seedfertility of NY M1 plants following irradiation with C ion
beams. The NY became seed sterile at 150 Gy and the
dosage to induce 50 % seed sterility is estimated as 50 – 60
Gy which differs slightly from the LD50.
The LD50 of ZZ sorghum by γ ray irradiation isestimated as 350 -500 Gy. On the contrary, the LD50 of ZZ
and DU by C ion beam irradiation is estimated at 30 and 50– 60 Gy, respectively, and a difference of irradiation
sensitivity is suggested (Fig.4). It is assumed that the larger
sorghum seeds reduced the degree of radiation penetrance
allowing some survival at 300 Gy.
We hope these data will be useful in our knock-out
mutation studies focused on estimating the influence ofapomixis genes in guineagrass1) and inducing unique mutantof sorghum for bio-fuel production.
Reference
1) Nakagawa, H. Breeding Research 9 (2007) 3 (inJapanese)

120

120

100

100

surviving rate (%)

Surviving rate (%)

Radio sensitivity to gamma (γ) ray and carbon (C) ion
beam irradiation were estimated in apomictic tetraploidguineagrass (Panicum maximum Jacq.) and diploid sexualsorghum (Sorghum bicolor (L.) Moench.). We irradiated theseed of cv. “Natsuyutaka (NY)” guineagrass and “Zhengzu(ZZ)” and “Durra (DU)” sorghum with γ rays and C ion
beams at varying dosages and observed the germination rate,
survival rate and seed fertility of M1 plants to identify the
optimum dosage of the irradiation. Gamma ray irradiation
was conducted at 50, 100, 200, 300, 400, 500, 600, 800,
1000 Gy to NY seeds at the IRB, Japan and sorghum seeds
in National Nuclear Energy Agency (BATAN) andcompared to the control (0 Gy). The C ion beam irradiation(220 MeV) was conducted at 10, 20, 30, 40, 50, 60, 80, 100,
150, 200 Gy to NY seeds and 50, 100, 150, 200, 300 Gy tosorghum seeds at Takasaki Ion Accelerators for Advanced
Radiation Application (TIARA).
The survival rate of NY by γ ray irradiation was notdecreased up to 400 Gy but gradually decreased to near
100% lethality at 1,000 Gy (Fig. 1). The survival rate by ion
beam irradiation rapidly diminished at 30 Gy with near
100% lethality at 200 Gy (Fig. 2). These data suggested that

80
60
40
20
0
0

200

400

600
Dose (Gy)

800

1000

80
60
40
20
0

1200

0

Fig. 1. Survival rate of “Natsuyutaka” atvarying dosages of gamma ray irradiation.

50

100
150
Dose (Gy)

200

250

Fig. 2. Survival rate of “Natsuyutaka” atvarying dosages of C ion beam irradiation.
100

1 0 0 .0
9 0 .0Survaival Rate (%)

S e e d S te rility

8 0 .07 0 .06 0 .05 0 .04 0 .03 0 .02 0 .01 0 .0

80
60
40
20
0

0 .0

0
0

20

40

60
80
100
G am m a Ray D o se (G y)

120

140

Fig. 3. Seed sterility of “Natsuyutaka” atvarying dosages of C ion beam irradiation.

50

100

150
200
Dose (Gy)

250

300

Fig. 4. Survival rate of “Zhengzu” at varying
dosages of C ion beam irradiation.

－ 72 －

350

JAEA-Review 2007-060

3-07 The Optimum Dose of Ion Beam Irradiation for Growthof Sugarcane
a)

a)

a)

a)

a)

a)

F. Tohjima , Y. Takenoshita , T. Shirao , T. Nagatani , M. Ooe , K. Ueno , Y. Haseb)and A. Tanakaa)Kagoshima Biotechnology Institute,b)b)Radiation-Applied Biology Division, QuBS, JAEA

Sugarcane cultivar "Ni17" has hard and harmful hair on its leaf sheath. We have intended to induce hairless or few hairmutants using ion beam irradiation to tissue cultured of leaf explants. In this study, we studied on growth of sugarcane using
JAEA AVF cyclotron. The efficiency of regeneration from callus, the mutation ratio of nursery plants and the selection ratioin field were observed. We have selected 20 few hair mutants among the 5,787 regenerated plants in 2006. The optimum
doses on growth were 2～3 Gy of 12C6+ at 320 MeV. Furthermore, we have continued characteristic investigation and fieldtest of the selected mutants.
再生率は、材料による差はあるが、2 Gy以上の照射線量において低下が認められ、4 Gyの照射線量で25 ％以下となることを報告した2）。今回ほ場生育を指標としたイオンビーム照射線量を検討した結果、2 Gy以上の線量において仮茎長や茎径の減少、不良変異の発生が認められた。以上のことから品種“Ni17”の葉片への照射に炭素イオンビーム（C320）を利用する場合、
有用変異体作出に適するイオンビーム照射線量は、2～3 Gy程度であると考えられた。
Table 1 The number of tested and selected plants in 2005~2006

Ion Energy Dos

12 6+

C

No.
No.
No.
of
selected Selection
regenerated plants at
rate
plants atplantsopen field
open field(MeV) (Gy)
0
1
2
3
320
4
5
8
10

1,50
1,09
1,38
1,36
206
215
13
16

44
26
35
60
4
15
1
3

3
2
3
11
0
0
1
0

(%)
0.2
0.2
0.2
0.8
0.0
0.0
7.7
0.0

Total

5,78

188

20

0.3

(m)

(mm)

3.00
2.50
2.00
1.50
0

1

2

Dose

3

4

（Gy）

Fig. 1 Effect of ion beam
Irradiation on stem length5

Stem diameter

Stem length

サトウキビ品種“Ni17”は株出し適性が高く、耐風性も強い 1) 。しかし、葉鞘部に着生する毛群（第57毛群）が粗剛であるため、収穫や採苗時の作業に支障をきたしている。我々は、イオンビームを利用した変異誘発によって毛群の少ない優良系統の育成を行っており、今回、サトウキビのほ場生育を指標としたイオンビーム照射線量を検討した。
“ Ni17”の幼葉組織の切片を2,4-D濃度 0.5～１
mg/l のカルス誘導培地に置床し、約一週間後に炭素
イオンビーム（320 MeV・ 12C6＋ ，以下C320）を照射した。照射は時期を変えて6回実施し、照射線量は1，2，
3，4，5，8，10 Gyの7水準とした。
照射後、カルス，不定胚を経由し再生させた植物体を発根処理し、順化を行った。2005年8月～2006年4月に鉢上げしたイオンビーム照射個体（5,787個体，無照射を含む）から、主として毛群の有無を基準とする
ガラス室内での幼苗検定により188個体を初期選抜した。選抜個体は、2006年6月1日及び5日にほ場に定植した。ほ場は厚層腐植質黒ボク土壌で畦間1.2m，株間
0.4 m，施肥法，栽培管理は慣行に従い、施肥量は窒素成分量で2 kg/aとした。その後11月上旬に最長仮茎長，茎径（最長茎における地上60 cm高さの稈直径），茎数，毛群の発生程度を調査した。
幼苗検定により初期選抜した188個体について、ほ場での毛群及び生育調査を行い、毛群が少なく生育の良好な有望個体20個体を選抜した（Table 1）。これ
らは現在もさらに生育特性に関して選抜中である。
イオンビーム照射によるサトウキビのほ場生育への影響を検討したところ（ほ場試験への供試個体数が少なかった8，10 Gyはグラフから省略）、仮茎長は1Gy
では無照射区と有意な差がなく、2 Gy以上では短くなった（Fig. 1）。茎径も同様に1 Gyでは無照射区と有意な差がなく、2 Gy以上では細くなった（Fig. 2）。
一方、茎数については，照射によって茎数が増加した個体が観察された（データ未掲載）。5Gy照射個体群
は仮茎長，茎径，茎数ともに個体間差が大きく、仮茎長，茎径の平均値が無照射区より劣ったことから生育への影響が大きいと考えられた。また、毛群について
は、各照射区において無照射区よりやや少なくなった個体が出現したが、無毛の個体は出現しなかった。
C320を照射した培養葉片が順化個体に再生する個体

30.0
25.0
20.0
15.0
0

1

2

3

Dose

（Gy）

4

5

Fig. 2 Effect of ion beam
Irradiation on stem diameter

References
1) M. Takemure et al., 鹿児島県農業試験場研究報告 32(2004) 81.
2) F. Tohjima, et al., JAEA Takasaki Annual Report.
2005（JAEA-Review 2006-042）83.

－ 73 －

JAEA-Review 2007-060

3-08 Ion Beam Breeding of Chrysanthemum Cultivar‘Sanyo-ohgon’
a)

a)

b)

b)

b)

T. Shirao , K. Ueno , K. Minami , A. Tanaka , S. Imakiire , Y. Hasea)c)and A. Tanakac)b)Kagoshima Biotechnology Institute, Kagoshima Prefectural Institute for Agriculturalc)
Development Flower Division, Radiation-Applied Biology Division, QuBS, JAEA

We worked on the ion beam breeding aimed to reduce lateral buds, or to improve flower size of Chrysanthemum cultivar‘Sanyo-ohgon’. In the individual selection of the first year, various flower shapes and days for flowering were observed in themutation, and 45 individuals were then selected from 6,186 regenerated plants. Also, a decrease in the amount of DNA wasobserved in the mutants with increasing the dose of ion beam irradiation. After vegetative propagation, the line selection
was performed by flowering in November or March, and two lines were then selected. Moreover, it was indicated that the reirradiation of the ion beam was effective in additional improvement of ‘Sanyo-ohgon’.
「山陽黄金１号」の側枝消失率が11月開花で12 ％，3
黄系秋輪ギク「山陽黄金」は、鹿児島県の主力品種
月開花で14 ％であったのに対し、供試系統は11月開であるが、側枝発生数が多く摘芽・摘蕾作業に労力を花で9～69 ％、3月開花で０～77％と系統による特性
要し、花がやや小さいなどの欠点がある。我々は、白の差が現れていた。小花数についても系統間差が大き
系秋輪ギク「神馬」において、葉片にイオンビームをく、11月開花で219～415枚、3月開花で150～324枚で照射し、不定芽経由の再生個体から無側枝性に優れたあった。無側枝性や花容草姿、ボリュームから2系統
変異個体を選抜し 1) 、品種登録を行った。また、育成（♯10，♯22）を選抜した（Table 1，2）。
した品種に再度イオンビームを照射することにより、DNA量が減少していない選抜系統の＃22に再度イオ
新たに低温開花性の特性を付与した個体の作出に成功
ンビームを照射して変異誘発個体を育成し、12月開花
している 2) 。今回、「山陽黄金」について、「神馬」の作型に3,215個体を供試した。これらの個体は供試と同様の手法を用いて無側枝性や花の大型化を目標とした元系統の特性を引き継ぎ、7割以上が栄養繁殖がしたイオンビーム育種に取り組んだ。
困難になる強無側枝性を示した。しかし、イオンビー
選抜系統で県内に供給されている「山陽黄金１号」
ム照射により、＃22より側枝数の増加した個体も一定の無菌植物の葉片（2×4 ㎜）に、原子力機構高崎研
割合で出現し、無側枝性が再度改変可能な特性であるのAVFサイクロトロンにより発生させたイオンビーム
ことが明らかとなった。これらの中から花容草姿の優（220 Mev・12C5+，320 MeV・12C6+）を1～3 Gy照射し、れる30個体を選抜したが、選抜個体の側枝消失率は
不定芽経由により再生個体を得た。これらの変異個体
30.1～88.1 ％で、小花数が増加した個体が観察されは初年目に12月開花の作型に供試し、生育調査とDNAた。これらのことから、当品種においてもイオンビー
量測定を行い、無側枝性や花容草姿に優れる個体を選ムの再照射による選抜個体の再改良が有効であると考抜した。次年度は選抜個体の系統選抜試験を実施し、えられる。
11月開花と3月開花の作型により、選抜特性の保持状況を調査した。また、選抜した優良系統はイオンビー
Table 1 Characteristics of the selected lines by flowering
ムの再照射（320 MeV・ 12C6+：0.5～3 Gy）による無側
in November
枝性や花容草姿の再改良に供試した。
number of days
plantweight of number ofrate of lost
number of
初年目の個体選抜試験では、供試した6,186個体か
line
to flowering
height (cm)
90cm (g) disbudding lateral buds (%)
florets
ら 、 45 個 体 を 選 抜 し た 。 選 抜 率 は 0.7% で 、 特 に ボ
#10
57
109
64
37
41
290
17
58
260
#22
53
106
76
リューム，無側枝性，花容の3点ともに優れる個体は4Sanyo-ohgon No1
52
97
82
52
12
298
個体であった。「山陽黄金」の花形は剣弁で、内側へThe dose of carbon ion beam irradiated at individual selections wereの抱え込みが少ないが、再生個体の中には、より顕著
220Me ･ 3Gy(#10) or 320MeV ･ 2Gy(#22).
Vな剣弁咲きや丸弁，抱え咲きなど様々な花形の個体が観察された。DNA量を測定した結果、不定芽を経由しTable 2
Characteristics of the selected lines byない茎頂培養由来の個体はDNA量の変化が認められな
floweringin
March
かったが、変異誘発個体は照射によるDNA量の減少が認められた。DNA量の減少は220 MeV-Cイオンで顕著に
number of days plantweight number of rate of lost number oflin
to flowering height
90cm (g) disbuddinglateral buds (%) florets
現れ、照射線量の増加に伴ってDNA量の減少した個体
#10
55
101
72
11
34
238
の割合も増加した。320 MeV-Cイオンの照射区は、DNA
#22
57
96
81
6
53
209
量の減少傾向は緩やかで、3 Gy照射区で220 MeV-Cの1
Sanyo-ohgon No1
52
90
65
20
14
210
～2 Gy照射区と同程度であった。
次年度の系統選抜試験に供試した45系統については、
References
到花日数は、11月開花及び3月開花とも「山陽黄金１
1) K. Ueno et al., TIARA Ann. Rep. 2002 (2003) 52.
号」と大きな差は認められなかった。無側枝性は、
2) K. Ueno et al., TIARA Ann. Rep. 2004 (2005) 60.

－ 74 －

JAEA-Review 2007-060

3-09 Induction of Mutations by the Ion Beam Irradiation to
the Bulb-scales of Lilium cv. Acapulco.
a)

a)

b)

M. Kondo , Y. Koike , Y. Hase , Y. Yokotab)and H. Kobayashia)a)Department of Biotechnology, Niigata Agricultural Research Instituteb)

Radiation-Applied Biology Division, QuBS, JAEA

Number of regenerated plants / 10 slice of scales

We have been working on producing marketable blue
lilies. It has been impossible to produce blue lilies bycrossbreeding or mutation, because they lack flavonoid
3',5'-hydroxylase (F3'5'H), which is necessary for synthesisof the blue pigment, delphinidin. Therefore, we developed
an Agrobacterium-mediated transformation system for lilies
to transfer the F3’5’H gene1). For the marketing of thetransformed blue lilies, we have to regulate the spreadingof the pollen to prevent them from crossing with other lilies,
because they are genetically modified plants. The aim of
this study is to produce of male-sterile lilies. In the present
study, we exposed bulb-scales of lilies to 4He2+ beams fromthe AVF cyclotron and investigated the effects on thebulb-scales.
Bulbs of the Oriental hybrid lily, Lilium cv. Acapulco,
were cultured under a 16 hr light/8 hr dark cycle at 25 °C on
bulb propagation medium, which consisted of modified MS
medium-1/2 NH4NO3 and KNO3, 40 g/l sucrose, and 3 g/lgellan gum. The diameter of the in vitro grown bulb was
about 10 mm or more. The penetration range of 50 MeV
4
He2+ was 1.45 mm. Therefore, we sliced the scales toabout 1.0 mm thickness. The sliced 10 scales were placedon a regeneration medium which consisted of modified MS
medium-1/2 NH4NO3 and KNO3, 30 g/l sucrose, 5 g/l gellan
gum, 0.1 mg/l picloram, and 0.01 mg/l 6-benzylaminopurine
and covered with sterilized Kapton polyimide film (7.5 µm
in thickness, 45 mm square in size, Toray-Dupon, Japan).
The scales were exposed at total doses of 0 Gy – 2.0 Gy of
50 MeV 4He2+ beams from the AVF cyclotron.
The exposed scales were transferred to the same fresh

medium and cultivated for 4 months. The culture were
performed under a 16 hr light/8 hr dark cycle at 25 °C.
The scales were maintained by subculturing every 2 months
onto the same fresh medium under the same condition.
Regenerated shoots were transferred to bulb propagation
medium and cultivated for 2 months. The number ofregenerated plants was counted 6 months after the ion beam
exposure.
It has been suggested that the irradiation doses thatsuppressed the proliferation rate to 50-90% were effective ininduction of mutations in cultured plant tissues 2), 3). In theirradiation of 50 MeV 4He2+, the doses of 0.2-0.8 Gy
suppressed the regeneration rate to 50-90 % of the
non-irradiated control (Fig. 1 ). We assumed from thisresult that the doses of 0.2–0.8 Gy of 50 MeV 4He2+ wereappropriate for obtaining mutants. In the irradiation of 50
MeV 4He2+, the doses of 0.2-0.6 Gy suppressed theproliferation rate of the calluses to 50-90 % of the
non-irradiated control 4). These results suggest that scales
are more insensitive to ion beams than calluses.
At present, the ion beam irradiation, regeneration,acclimatization and planting to a field are in progress toselect male-sterile mutants of lilies (Fig. 2).
References
1) Y. Hoshi et al., Plant Cell Rep. 22 (2004) 359.
2) M. Okamura et al., Nucl. Instr. Meth. B 206 (2003) 579.
3) S. Nagatomi et al., TIARA annual Rep. 1995 (1996) 50.
4) M.Kondo et al., JAEA Takasaki Annual Rep. 2005
(2007) 8.

150

100

50

0

0

0.2

0.4 0.6 0.8
1
Dose （Gy）

1.2

1.4

1.6 1.8 2.0

Fig.1 Effects of 50 MeV ４ He ２ ＋ exposure on theregeneration from scales. Values represent themeans of 3 experiments. (Bar = standard error)

Fig.2 Ion beam-irradiated plants of “Acapulco” wereplanted and grown in a field in order to investigate
the pollen fertility.

－ 75 －

JAEA-Review 2007-060

3-10 Development of New Commercial Strains in Functional
Mushroom by Ion Beam Irradiationa)Y. Kawashima , Y. Haseb)and Y. Yokota

a)

b)

b)

Gunma Prefectural Forestry Experiment Station, Radiation-Applied Biology
Division,QuBS,JAEA

In Pleurotus osutreatus and Lyophyllum decastes,the increase in dose causes the reduction of mycelial growth. So we
examined the mutagenic effect of ion beams on Pleurotus eringii,Ganoderma lucidum and Grifora flondosa. As in Pleurotus
osutreatus and Lyophyllum decastes,we found that the increase in dose causes the reduction of mycelial growth. The
regeneration rate went down at 600 Gy in 12C6+ beams and few spores germinated at 700 Gy in 12C6+ beams. However, nomorphological changes were observed in the fruit bodies.
これらの結果はハタケシメジ及びヒラタケとほぼ同様
であり 2),3) 、きのこ類の２核菌糸においては、イオンビーム照射の致死線量は700 Gy前後であることが推察
された。
0Gy
50Gy
100Gy
200Gy
300Gy
400Gy
500Gy
600Gy
700Gy
800Gy
1000Gy50

Growth (mm)

45
40
35
30
25
20
15
10
5
0

0

4

8

10

14

17

21

経過日数

Fig.1 Effect of ion beam irradiation on mycelia growth of Pleurotus eryngii.
50

0Gy
50Gy
100Gy
200Gy
300Gy
400Gy
500Gy
600Gy
700Gy
800Gy
1000Gy45
40

Growth (mm)

近年、植物育種における変異原として、量子ビームの利用が花卉をはじめ果樹、野菜などに広まり、成果がみられる。しかし、きのこ類においては紫外線やγ線を変異原とした報告はいくつかみられるのみである
1),4)。
きのこ類の生産は群馬県などの中山間地域の主要な産業のひとつである。しかし、大手企業の参入、消費者ニーズの多様化、輸入量の増加などによりきびしい状況にある。
そこで、きのこ類の育種に量子ビームを利用して、突然変異を誘発することにより新品種を開発するために、致死線量の把握及び栽培試験を行った。
1. 実験方法
当場保有のエリンギGPLE-15菌株、マンネンタケ
GGL-5菌株及びマイタケGGF-7,33菌株の２核菌糸体を供試体として用いた。直径３ mmのコルクボーラーで打 ち 抜 い た ２ 核 菌 糸 体 を 直 径 50 mm プ ラ ス チ ッ ク
シャーレのPDA培地上に置床して、イオンビームまたはγ線を照射し、菌糸成長量を測定した。照射線量は
イオンビームが100～1000 Gyとした。
イオンビーム（加速粒子 12C6＋ 、320 MeV）の照射は、
高崎量子応用研究所にあるイオン照射施設「TIARA」のAVFサイクロトロンで行った。
照射後に菌糸成長が認められたエリンギ及びマイタ
ケの供試体については、栽培に供して子実体の形状における突然変異体の出現及び胞子形成の有無を観察した。培地基材はブナオガコ、培地添加物は生コメヌカ
またはホミニーフィードとし、容積比で10：２に混合し、含水率を65％に調整した後、ＰＰ製容器に詰め込んだ。滅菌は高圧滅菌とし、培地内温度が120℃に達した後40分間行った。培養温度は22 ℃とし、培養した後に温度15～17℃、湿度90 ％の発生室に移動し、子実体の発生を促した。
2. 結果及び考察
エリンギ及びマンネンタケ菌糸体について菌糸成長量とイオンビーム線量の関係を図－１及び２に示した。
照射した試験区はいずれもコントロールに比べて成長量は少ない傾向がみられたものの、600 Gyにおいても菌糸が成長することがわかった。なお、700 Gy以上を照射した試験区については、菌糸の成長は認められな
かった。

35
30
25
20
15
10
5
0
0

4

8

10

14

17

21

経過日数

Fig.2 Effect of ion beam irradiation on mycelia growth of Grifora flondosa.

エリンギとマイタケの栽培試験の結果においては、子実体の形状の突然変異及び胞子欠損は認められなかった。しかし、ヒラタケにおいては突然変異の出現がみられており 3) 、イオンビームの照射はきのこ類の突然変異の誘発に有効な手段であると思われる。
References
1)S.Nagatomi, Ins. Radiat. et al., Breeding Technical News
50 (1995).
2)Y.Kawashima et.al., TIARA Ann.Rep.2004 (2005) 96.
3)Y.Kawashima et.al., JAEA Takasaki Ann Rep.2005(2006) 91.
4)Y.Obatake,et al., Mycoscience 44 (2003) 33.

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JAEA-Review 2007-060

3-11 Mutation Induction of Asiatic Hybrid Lily and Lilium ×
formolongi Hort. Using Ion Beam Irradiation
a)

a)

a)

a)

b)

N. Chiba , K. Arakawa , S. Nakamura , S. Suzuki , Y. Yokota , Y. Hase)and I. Narumi bb)a)Miyagi Prefectural Agriculture and Horticulture Research Centerb)
Radiation-Applied Biology Division, QuBS, JAEA

We investigated mutants of Asiatic hybrid lily and Lilium × formolongi Hort. induced by ion beam irradiation. Six flower
color mutants were observed in M1 generation of Asiatic hybrid lily, and Two pollenless mutants were observed in M2
generation of L. × formolongi . Carbon ion irradiation seemed to be more effective than Helium ion to induce mutants ofAsiatic hybrid lily.
１．はじめにスカシユリ（Asiatic hybrid lily）は、赤，桃，橙，黄等の花色で球根により繁殖し、シンテッポウユリ（Lilium × formolongi Hort.）は白花で種子繁殖性の園芸植物である。本試験では品種改良を目的に、ス
カシユリとシンテッポウユリに対して、イオンビーム
による突然変異を誘発し、花の諸形質における遺伝的変異の拡大をねらった。
２．実験方法無菌培養で増殖したスカシユリの２品種ロリーポッ
プ（花色：赤白）とチャンティ（花色：桃）のりん片に炭素12C6+(320 MeV)またはヘリウム４He2+(100 MeV）を照射した。その後にりん片から再生した個体をM1世代とし、ほ場で栽培し開花時に変異の有無を調査した1)。
シンテッポウユリについては、品種オーガスタの種
子に炭素12C6+（320 MeV）を照射処理しM1世代を育成した。M1世代の自殖により変異した遺伝子座をホモ化し、得られたM2世代をほ場で栽培し開花時に変異の有無を調査した。
３．結果及び考察
スカシユリでは花色に関する６系統の変異体が得られた。ロリーポップの変異体４系統は全てFig. 1(B)に示した花の白色化であった。チャンティではFig. 1(D)に示した花色の変異体と、花被片の先端が白い変異体が得られた。ロリーポップにおいて、炭素イオンとヘリウムイオンの効果を同線量で比較した場合、突然変
異率は、炭素イオンが高い傾向であった（Table 1）。
シンテッポウユリのM1世代では、変異体が観察されなかった。M2世代では花色等の変異は無かったが、花粉が生産されない２系統の変異体を得ることができた（Table
2）。

Table 1 Number of observed mutants and estimatedmutation rates in Asiatic hybrid lily by ion beamirradiation.
Cultivar

Ion

Lolly pop

12 6+

C

4

2+

He

Chanty12 6+

CDose No. of M1 No. of Mutants Mutation Rate
(Gy)
(%)
0.5
90
1
1.1
1.0
40
1
2.5
0.5
336
0
0
1.0
232
2
0.86
0.5
75
2
2.7

Table 2 Number of observed mutants and estimatedmutation rates in L.× formolongi by carbon ion
irradiation.
Cultivar

Ion

Augusta

12 6+

CDose No. of M2 No. of Mutants Mutation Rate
(Gy)
(%)
1
445
1
0.22
2
521
1
0.19

(A)

(B)

(C)

(D)

Fig. 1 Mutation of flower color in Asiatic hibrid lily.
Normal (A) and Mutant (B) of cultivar ‘Lolly pop’.
Normal (C) and Mutant (D) of cultivar ‘Chanty’.

Reference
１) N. Chiba et al., TIARA annual report 2005 (2007) 92.

－ 77 －

JAEA-Review 2007-060

3-12 Dose Response and Mutation Induction by Ion Beam
Irradiation in Chrysanthemum
a)

a)

b)

A. Matsumura , N. Furutani , Y. Hase , Y. Yokotab)and A. Tanakab)a)Kyoto Prefectural Institute of Agricultural Biotechnology,b)
Radiation-Applied Biology Division, QuBS, JAEA

Recently irradiation of ion beam has become a new method for mutation breeding of chrysanthemum. This
study was conducted to investigate the effect of ion beam irradiation on mutant induction of chrysanthemum
cultivars (‘H13’ and ‘Shiroyamate’). Irradiation of ion beam induced flower colour changing; that is, yellow
mutant was successfully obtained from ‘Shiroyamate’, and vermilion and white/red mutants were also induced
from ‘H13’. These results suggest that the ion beam irradiation would be valuable for mutation induction inchrysanthemum flower.
さらに花色変異の幅を広げていきたいと考えている。
盆コギクは、仏花として出荷期が決まっているが、天候による開花変動が大きく、産地では危険分散のた
Table 1 Mutation induction in ‘Shiroyamate’ by 12C5+ ion
めに多くの品種が作付けされている。
beam irradiation
こうした中、京都府では開花変動の少ない赤色系統
No. ofFlowerPollenLeaf‘H13’（赤紫色）を育成した。しかし、盆コギクと
Does
Dwarf
plants mutation asterility
mutation b
しては赤・白・黄の3色セットが望まれる。そこで、
(Gy)
(%)
(%)
(%)
(%)
イオンビームを用いた突然変異育種法に取り組むこと
Cont
30
0
0
0
126
0.8
4
0
0
とした。イオンビームは、ガンマ線やＸ線などの放射
1
482
2.3
1
6.8
5
線を用いた育種と比較して幅広い変異を示すことが知
2
424
4
3.8
10.1
5.4
1)
られており 、キクでは花色変異品種をはじめ、多く
4
443
7.4
2.7
23.3
12.2
の品種が育成されている。
8
360
9.7
11.1
28.9
7.5
16
88
1.1
0
10.2
0
本研究では、‘H13’及び在来白色品種‘白山手’
32
46
6.5
0
8.7
0
から、イオンビーム照射と培養により白色や黄色等にaFlower mutation indicates yellow mutantsb
変化した品種を育成するために、花弁あるいは葉片にLeaf mutation indicates that leaf shape was mutated from serrated to
イオンビームを照射し、変異体の作出を試みた。
round‘白山手’の花弁を3～5 mmに調製し、NAA 10 mg/lとBA 3 mg/lを添加したMS培地を10ml含む60 mmシャー
E
C
A
レに置床した。一方、‘H13’は葉片を3～5 mmに調製し、NAA 0.1 mg/lとBA 0.5 mg/lを添加したMS培地を10ml含む60 mmシャーレに置床した。次に、日本原子力研究開発機構 (高崎市) イオン照射研究施設のAVF
サイクロトロンを用いて、これらサンプルに加速粒子
12 5+
D
F
C 、エネルギー220 MeVで0～32 Gyの範囲で照射し、 B培養によりシュートを再生させた。順次、順化・育苗
した後、‘白山手’はビニールハウスに定植、H13は４号ポットに鉢上げしてガラス温室内で栽培し、開花調査を実施した。
‘白山手’では、イオンビームの線量が高くなるに
Fig. 1 Selected mutants from ‘Shiroyamate’ and ‘H13’
伴い、黄色花及び無花粉株の出現率が高くなった
A: ‘Shiroyamate’ (Normal)（Table 1 and Fig. 1）。また、葉の波打ちや矮化など
B: Yellow variety from ‘Shiroyamate’の変異率も高まり、8 Gy以上では半数以上の個体に変
C: ‘H13’ (Normal)
異が現れた。これら結果から、‘白山手’の花弁に照
D: Vermilion variety from ‘H13’
射するイオンビームの線量は4 Gy以下が適すると考え
E: Red/white variety form ‘H13’られた。
F: Cylinder-shaped variety from ‘H13’‘H13’への照射では、濃赤色、朱色、桃色などの花色変異体が得られた（Fig. 1）。また花形や花房にReference
も変異が認められた。現在、これら再生植物体をほ場
1) S. Nagatomi, et al., TIARA Annual Report 1997 (1998)に定植し、慣行法により栽培を行っている。今後、花41.
色や草型等の特性を調べ、有望系統を選抜するとともに、得られた花色変異株に再度イオンビームを照射し、－ 78 －

JAEA-Review 2007-060

3-13 Induction of Thornless Yuzu Mutant by Heavy Ion Beam
Irradiation
a)

b)

b)

b)

Y. Matsuo , Y. Hase , Y. Yokota , I. Narumi and E. Ohyabua)a)Saga Prefectural Agricultural Research Center, b) Radiation-Applied Biology Division,
QuBS, JAEA

Yuzu (Citrus junos) tree bears long thorns that deteriorate fruit quality. We are trying to produce thornless mutant of Yuzu
by carbon-ion irradiation. Cut surface of lower hypocotyls were exposed to carbon ions with a total energy of 320 MeV.
Based on the shoot regeneration rate, we determined less than 8 Gy is appropriate for our culture system. We successfully
obtained completely thornless mutant together with several mutant plants with weak thorns or lesser number of thorns. We
grafted these mutant plants into rough lemon (Citrus jambhiri) to grow up quickly, and will examine their thornless traits.
ユズは樹体に長いトゲが発生するため、栽培管理上
１ Gyを除き各線量とも出現した。これらの個体以外障害となっている。さらに、トゲによる刺し傷はキズに、初期生育が緩慢で判断がつかない個体もあったた
果や腐敗果の発生など果実の商品性を低下させる。そめ、ラフレモン等に寄せ接ぎを実施し確認を急ぎたい。
こで、ユズ実生の胚軸断面からシュートを再生させる
培養系に重イオンビームを照射しトゲ消失変異体の作出を試みた。今回はシュート再生率などを指標とした
Table 1. Shoot regeneration rate from hypocotyls irradiated with
照射条件や変異体作出に最適な線量の検討を行うととcarbon ions.
もに、再生シュートを育成し、トゲ消失変異個体を得
1 week after irradiation
2 week after irradiationr
No. ofたので報告する。
Dose
Regeneration
irradiation No. of shoots Regeneration
No. of shoots
rate
rate
試験１ ユズ（Citrus junos Sieb.ex Tanaka)種子
(Gy)
(%)
(%)
0
10
11
110
15
150
を1/2ＭＳ培地に播種後、３週間目に胚軸を２cm程度
1
10
10
100
12
120
2
10
10
100
11
110
残し切断した。さらに、１週間後に切断面より発生し
4
10
10
100
9
90
たカルスに重イオンビームを照射した。照射線種はＣ
8
10
8
80
6
60
16
10
1
10
2
20
12
6+
イオン（ Ｃ
総エネルギー320 MeV）を用い、照射
32
10
0
0
0
0
64
10
0
0
0
0
線量は１ Gy、２ Gy、４ Gy、８ Gy、16 Gy、32 Gy、
128
10
0
0
0
0
256
10
0
0
0
0
64Gy、128Gy、256Gyの９線量区とした。照射施設は原
子力機構高崎量子応用研究所のAVFサイクロトロンをTable 2. Effects of carbon ion irradiation on root growth.
用いた。照射後、再分化個体数及び根の伸長量を調査
3 week after irradiation
4 week after irradiation
した。
No. ofDose
No. ofNo. ofirradiation
Root length
Root length
roots
roots
試験２ 試験１の結果を踏まえ、線量を１Gy、２Gy、
(Gy)
(mm)
(mm)
４Gy、８Gyの４線量区で照射を実施し、再分化を確認
0
10
8
12.3
8
28.7
1
10
6
12.4
7
24.9
後、馴化培地へ継代培養した。さらに、培土に鉢上げ
2
10
7
13.3
6
25
4
10
6
9.9
6
30
し、トゲの発生が見られない個体についてはラフレモ
8
10
7
11.7
6
20.6
16
10
4
15
5
24.6
ン等に寄せ接ぎを行い伸長促進を図りトゲの発生状況
32
10
6
10.6
8
17.8
64
10
8
11.3
8
21.5
を確認した。
128
10
6
7.7
4
15.3
試験１ ２週間後の再分化シュートの発生率は、２
256
10
4
10.4
4
22.6
Gy以下では100 ％以上であり、また８ Gyでも60 ％は再分化した。なお、シュートの発生率が100 ％を越えるのは１胚軸より複数発生したものである。照射線量が32 Gy以上の場合シュート発生は認められなかったが、根の伸長は確認できた。根の伸長量については、（ａ）
照射線量が増加しても顕著な影響は見られなかった。
これは、重イオンではＸ線等とは異なり、到達深度が（ｂ）
浅いため、根の発生阻害が起こりにくいものと考えら
れ、照射時には植物体根部（地下部）の保護は必要ないと言える。以上の結果より、ユズ実生に重イオンビームを照射する線量は８ Gy以下で検討していくこととした。
Figure 1. (a) Thornless Yuzu mutant. (b) Normal
試験２ 各線量区とも200個体前後に照射を実施しshoot with long thorns that is regenerated
た結果、２ Gy区で完全無刺個体を獲得することがでfrom the same hypocotyls.
きた。また、トゲの発生がほとんど見られない個体は－ 79 －

JAEA-Review 2007-060

3-14 Producing New Gene Resources in Fig by Using
Ion-beam Irradiation
a)

a)

a)

a)

b)

I. Asami , S. Fukuta , S. Kuroyanagi , T. Ooya , Y. Hase , Y. Yokotab)and I. Narumi
a)

b)

b)

Aichi-ken Agricultural Research Center, Radiation-Applied Biology Division, QuBS, JAEA

The goles of our study are to produce new gene resources in fig by mutation induction with ion-beam irradiation, because
the breading by varietal crossing in fig is very difficult. As the first paper of our study, we report the influences of carbon ion
beams and soft X-rays irradiation to in vitro lateral buds on mutation induction in fig ‘Masui-dorfin’. In vitro buds were
irradiated with carbon ion beams (320 MeV 12C6+ ) at various doses of 0 – 40 Gy at TIARA, and with soft X-rays (100 KVp,
5 mA, 191 Gy/Hr) at Aichi Agric.Res.Ctr. at various doses of 0 – 160 Gy. The efficiency of survival rate of buds, the fresh
weight and the length of lateral shoots, and the rate of shoot that grows over 1 cm were observed. The optimum doses forcarbon ion beams and soft X-rays were 5 Gy of 320 MeV 12C6+ and 60 Gy of soft X-rays, respectively.
たものの腋芽の伸長が抑えられることが多く、10 ㎜
日本のイチジク産地で栽培されている品種は、その以上伸長した腋芽の割合が50 ％を切るのは40 Gyからほとんどが“桝井ドーフィン”であり、遺伝子資源と80 Gyの間であった（Fig.２）。
しては非常に限られたものになっている。さらに、日本の湿潤気候での栽培に適したフィッグ型イチジク品
それぞれ２回目の試験を行ったところ、腋芽の生育
種はほとんど単性花（雌花）しか着生しない１）ことかが非照射区の50 ％程度に低下する線量は、炭素イオ
ンビームで５ Gy、軟Ｘ線では60 Gyあった（データ未ら他品種との交雑育種は困難であり、これまで遺伝子掲載）。
資源の拡大はされてこなかった。そこで本課題では、
イオンビームを利用して高品質でかつ特徴のあるイチ以上の結果、両線種について腋芽の生育に同程度のジク新品種開発につながる遺伝子資源を創成する。本
影響が現れる線量を比較すると、炭素イオンビームは
年度はイチジクへの適切な照射方法を確立するために、 軟Ｘ線の十分の一以下であった。
培養苗腋芽への炭素イオンビーム及び軟Ｘ線の照射効
果を調査する。
無菌培養したイチジク“品種：桝井ドーフィン”の
茎頂部と葉を切除した茎部を節ごとに切断し、６㎝径
プラスチックシャーレ内にＭＳ液体培地（ショ糖３％、ホルモン無し）を含ませた生け花用オアシス（発砲フェノール樹脂）を入れ、腋芽の向きを上に揃えて挿した。同シャーレ内の試料に加速した炭素イオン粒子（320 MeV・ 12C6 ＋ 、LET：86 keV／μm）を種々の線量で照射した。また、比較のため愛知農総試保有の軟Ｘ
線照射装置（ソフテックス株式会社製M-100 WE型：
100 KVp、5 mA、191 Gy／Hr）を用いて同様の方法で Fig.1 Influence of 320 MeV carbon ion beam irradiation to on
growth of in vitro lateral buds in Fig‘Masui-dorfin’.
照射した。照射済試料はＭＳ液体培地（ショ糖３％、ホルモン無し）を含ませた育苗用オアシス（Oasis5710）に挿し、プラントボックス内で育てた。
培養は25 ℃、16時間日長で行い、培養60日後の腋芽の生存率、10 mm以上伸長した腋芽の割合、腋芽の茎長及び腋芽重量を調査した。試験はそれぞれ２回ずつ行い、各試験区ごとに腋芽30～40節を供試した。
炭素イオンビームを５ Gyから40 Gyまで段階照射したところ、15 Gy以上で生存する腋芽の割合が低下し始め、30 Gy以上では全て枯死した。また、10 ㎜以上伸長する腋芽の割合、伸長した腋芽の茎長及び腋芽重 Fig.2 Influence of soft X-ray irradiation on growth of in vitro
量は５ Gy照射で非照射区（０Gy）の平均値に対して
lateral buds in Fig‘Masui-dorfin’.
50 ％程度にまで低下した。腋芽が生存しても伸長しなければ選抜に用いることができないことから、10Reference㎜以上伸長する腋芽がわずかに残る10 Gyが限界であ1）平田尚美.農業技術体系-果樹編５,東京,農文協.イ
ると考えられた（Fig.１）。
軟Ｘ線を10 Gyから160 Gyまで段階照射したところ、 チジク,基29（1993).
80 Gy以上になると腋芽生存率が低下した。生存はし－ 80 －

JAEA-Review 2007-060

3-15 Induction of New Color Variation by Irradiation of Ion
Beams to Light Yellow ‘Jinba’
a)

b)

a)

b)

T. Toyoda , H. Watanabe , K. Emoto , S. Yoshimatsu , Y. Hasea)and S. Kamisoyamac)a)Paddy Farming Research Institute, Oita Prefectural Agriculture, Forestry and Fisheriesb)Research Center, Floriculture Research Institute, Oita Prefectural Agriculture, Forestry andc)Fisheries Research Center, Radiation-Applied Biology Division, QuBS, JAEA
‘Jinba’ is a white chrysanthemum. In 2002, we found a light yellow variant of ‘Jinba’ at south area of Oita prefecture. So,
we have intended to induce deep yellow ‘Jinba’ using ion beam irradiation(12C6+:320MeV,1・2・3 Gy) to this light yellow‘Jinba’. Leaves or petals were cut and cultured on the regeneration MS medium and irradiated. Five mutants (2 Gy:2
mutants,3 Gy:3 mutants) which showed deep yellow at flower bud time were obtained. But their petals gradually became
white toward flowering.
秋輪ギク「神馬」(白)は、大分県南部の佐伯市を中心に多く栽培されている。しかし、「神馬」の栽培特性に類似した高品質の黄色品種がなく､黄色品種を多く生産できないことが、生産・販売戦略上大きな障害となっている。また、花き研究所では、平成 14 年度に佐伯市蒲江町で発見された「神馬」淡黄色系統について、系統選抜を行い、濃黄色系統を選抜してきたが、開花時に退色する欠点を改善されていない。
そこで、「神馬」淡黄色系統に対して花色変異に有効なイオンビーム照射を行い、花色変異の誘発を試みた。
供試材料は､「神馬」淡黄色系統（以下元株）無菌培
養中の葉片及び花弁を用いた。葉片は 2×5mm､花弁は2×5～7mm 程度に切断し､不定芽形成培地〔MS 培地+NAA2.0mg/L+BA1.0 mg/L(ショ糖 3%、寒天 0.8％、
pH5.8）〕に置床し、1 週間程度培養したものに、8 月 21
日にイオンビームを照射した。照射後、同じ不定芽形
成培地へ継代し、3～4 週間培養後､不定芽伸長培地〔MS培地+NAA0.01 mg/L+BA0.05 mg/L(ショ糖 3 %、寒天
0.8 ％、pH5.8）〕へ移植した。照射は、TIARA 内の AVF
サイクロトロンを利用し、12C6+：320 MeV、1、2、3 Gy
を 15 シャーレ照射した 1)。
再生した植物体は順次発根､順化､鉢上げを行い､開花させて花色の確認を行った。色彩値（Hunter b 値）は色彩色差計（CR-321、MINOLTA）で測定した。
その結果、葉片からの再生個体数は、1・２ Gy を照射したものは同程度だったが､３ Gy を照射したものは､
1・２ Gy と比較して半分程度であった(Table1)。
花弁から伸長したシュートは、照射線量に関係なくビトリフィケーションが多く発生したが、発根培地にフロリアライトを利用することにより､約１カ月後には、症状はほぼ改善され､鉢上げが可能となった。
鉢上げした再生個体の開花は、早い個体で 1 月下旬
から始まった。この中から元株よりも黄色の濃い個体
を、3 Gy 照射により得られた個体から３個体、2 Gy 照射により得られた個体から 2 個体(以下濃黄化個体)を選抜したが、全て葉片由来のものであった。また、再生個体数との関係から、線量が強い方が濃黄化個体が得られやすい傾向があった。
選抜した 5 個体は、元株と比較して切り前時の黄色が濃くなり(b 値)、黄色スプレーギクと同等の濃さであっが、開花時に外弁が退色するため、黄色品種として利用することは困難だと思われた(Table2,Fig.1)。今後も、再生個体の開花処理と調査を継続するとともに、選抜
濃黄化個体への再照射を検討していきたい。
Reference
1)鹿児島県バイオテクノロジー研究所成績概要書(2000～2002)
Table 1.

The number of regenerated and selected plants

TissueLeaf

R egenerated plants
Selected plants
R egenerated plants
Selected plants

Petal

Table 2 .

C

6+

1
520
0
23
0

Total

:D ose(Gy)
2
3
492
233
2
3
41
73
0
0

1,245
5
137
0

Changes of color indices b
In d ivid u al

D o se(G y)

L igh t yello w ‘Jin b a’

‐
3
3
3
2
2
‐

3 0 .8 4

2 3 .6 7

1 .5 73 7 .2 5
4 0 .6 1
4 3 .3 3
4 3 .0 7
3 7 .9 4
1 1 .1 6

3 5 .4 9
3 7 .3 0
3 4 .7 8
2 5 .9 4
3 1 .0 7
2 .0 2

1 .4 02 .8 01 0 .2 7
1 6 .4 7
4 .6 1
2 .4 1‐4 1 .0 9

3 8 .1 2

3 4 .8 2

N o .8N o .1 0
N o .1 1
N o .1 2
N o .1 3‘Jin b a’Y ello w ch rysan th em u mo f sp ray typ e－ 81 －

12

N o. of plants

A

B ud

B

Fig.1

F u ll b lo o m
In sid e
O u tsid eCDSelected flower color mutants

A : Light yellow Jinba B : No.11
Upper : Bud

C:No.12

D:No.13

Lower : Flower

JAEA-Review 2007-060

3-16 Ion Beam Breeding of Flower Color Variations inTransgenic Plants with Multi-Disease Tolerance
a)

a)

a)

b)

M. Okamura , A. Shimizu , S. Watanabe , Y. Hase , I. Narumia)b)

and A. Tanakab)b)Plant Research Center, Kirin Agribio Co., LTD., Radiation-applied Biology Division, QuBS, JAEA

1. Introduction
Ion beams have different effect from that of electron
beams on mutation generation of crops and have great
impact on plant seed and seedling business. New carnation
variety series with 10 flower color variations have beendeveloped by ion beam breeding in the joint R&D between
Kirin Agribio Co., LTD. and JAEA. They have beencommercialized in Japan and Europe 1).
We are trying to develop an advanced application system
of ion beams to produce color variations or to add
improvements in transgenic plants that have acquired usefulcharacteristics such as tolerance to multi-diseases byrecombinant DNA techniques.
2. Materials and Methods
Agrobacterium-mediated transgenic chrysanthemum plants(Dendranthema grandiflora) expressing double-stranded
RNA-specific ribonuclease gene (pac1) derived from
Schizosaccharomyces pombe were used as materials for ion
beam breeding. Leaf segments were placed in petri dishes
containing Murashige and Skoog medium supplemented
with 0.05 mg/l NAA and 0.1 mg/l BA, 30 g/l sucrose and 7
g/l agar. The samples covered with Kapton film were
irradiated with 220 MeV or 320 MeV carbon ion beams
from the TIARA AVF cyclotron (JAEA, Takasaki). In vitro
plants derived from ion beam irradiation have been
acclimatized and cultivated in the greenhouse and theirflower color and shape were investigated.
3. Results and Discussions
Transgenic chrysanthemum plants expressing pac1 gene
showed tolerance against Chrysanthemum Stunt Viroid(CSVd) and Tomato Spotted Wilt Virus (TSWV) 2). The
tolerance of pac1 transgenic chrysanthemum to CSVd isshown in Figure 1.
Thus fur 400 plants derived from 3 Gy to 10 Gy irradiationof 220 MeV or 320 MeV carbon ion beams have beencultivated in the greenhouse and flowered. Flower color
mutants such as pale pink, dark pink, salmon etc. have beenobtained (Figure 2).
The control of viroid disease has been very difficult
because factors essential for viroid survival are
indispensable to the host plants. Viruses belonging to thegenus Tospovirus including TSWV are very serious
pathogens not only in chrysanthemum but on otherhorticultural plants. Ion beam breeding is effective to
produce color variations, once the transgenic plants withvirus- and viroid-resintance have been acquired.

From these results we confirmed that the advanced
application system of ion beams will contribute to thedevelopment of variety series of ornamentals with highquality at lower cost, as compared with the method to
introduce useful characteristics into several varieties withdifferent flower color by transformation one by one.

Figure 1. Symptoms by CSVd infection. (from left to right)
Non-transgenic without infection, non- transgenic with
CSVd infection, transgenic without infection, transgenic
with CSVd infection

Figure 2. Flower color mutants obtained from ion beam
breeding of transgenic chrysanthemum plants withmulti-disease tolerance. (from left to right) parent, dark
pink, salmon, light pink
References
1) Okamura M. et.al. Floriculture, Oranamental and Plant
Biotechnology Vol.I, Global Science Books (2006)
p.619
2) Ogawa T. et.al. Breeding Science 55 (2005) 49.

－ 82 －

JAEA-Review 2007-060

3-17 Mutation Induction on Oriental Hybrid Lily
Irradiated with Ion Beams
a)

a)

a)

a)

a)

S. Chinone , A. Ishizawa , K. Tokuhiro , K. Nakatsubo , M. Amano ,b)b)b)
Y. Hase , I. Narumi and A. Tanakaa)b)

Kaneko Seeds CO., LTD., Radiation-Applied Biology Division, QuBS, JAEA

To obtain mutants of Oriental hybrid Lily, we investigated the influences of ion beams irradiation to bulb scales in vitro.
Survival rates of scales irradiated with 320 MeV carbon and 50 MeV helium ion decreased at 0.2 and 1.5Gy, respectively.
The suitable dose was estimated to be around 0.2-0.4Gy in carbon ion and 1.5-2.0 Gy in helium ion. Leaf color mutations
which chlorophyll were defected partly or wholly were observed.
12 6＋
ユリ属においてイオンビーム照射によって誘発された変異C 照射したりん片から形成された小球根を817個体、4
体としては、アジアティックハイブリッド系ユリで花色や花He2＋では641個体を定植したところ、クロロフィルが完全に型の変化、花被片の斑点の減少が報告されている1）。本研究 または部分的に欠損している個体が観察された（Table.1，
ではオリエンタルハイブリッド系ユリの花色，雄性不稔，八 Fig.2）。今後は球根養成を行い花色，花型や雄性不稔等の特重化および草姿などにおいて特徴のある変異体獲得を目的と 性について調査する予定である。
してイオンビーム照射を行った。
無菌的に培養しているカネコ種苗㈱育成のオリエンタルハ
イブリッド系ユリ‘LC96-005-11’の小球根のりん片を、小球根形成培地を分注した60 mmシャーレに向軸面を上にして置床し、約1週間後に照射を行った。イオンビーム照射は日
本原子力研究開発機構イオンビーム照射研究施設（TIARA）のAVFサイクロトロンを用いて，炭素イオン（12C6＋，320
MeV）を0.1，0.2，0.4，0.6およ、び0.8 Gy，ヘリウムイオン（4He2＋,50 MeV）を0.5，1.0，1.5，2.0および2.5 Gyで照射した。照射後新しい小球根形成培地に移植し、1～2ヶ月後に生存率や小球根形成数などについて調査した。形成された小球 Fig.1. Influence of 320 MeV carbon ion beam irradiation to bulb
scale on survival rate in Lily.
根は直径が10 mm前後の大きさになるまで培養し、順次定植した。
照射したりん片の生存率や生育量は無照射のりん片に比べ Table.1. The number of leaf color mutants induced by ion beamirradiation.
て低下し、その影響は12C6＋照射の方が4He2＋照射より大きDose(Gy)
Dose(Gy)
No. ofNo. ofNo. ofNo. of
かった（データ略）。
12 6＋
bulbs
leaf
mutants
bulbs
leaf
mutants
C 照射による生存率は0，0.1および0.2 Gyの線量まではControl
Control28032
090 ％以上であったが、0.4 Gyでは80 ％に低下し、0.8 Gyに 12 6+
4
0.1
200
0
126
0
C
He2+ 0.5なると著しく低下した（Fig.1）。小球根形成数は0.2Gyまで
0.2
245
4
1.0
146
0
0.4
143
1
1.5
176
0
は線量とともに増加したが、それ以上の線量になると減少し
0.6
142
0
2.0
119
1
た。シュートおよび根の生育は0.6 Gy以上では著しく抑制さ
0.8
59
0
2.5
42
0
れ、発根しない球根も認められるようになった。
4
He2＋照射による生存率は0～2.0 Gyの間では80～100 ％であったが、2.5 Gyになると60 ％に低下した（データ略）。小球根形成数は1.5Gyで最も多くなり、2.5 Gyでは著しく減少した。2.0 Gyより線量が強くなるとシュートや根の生育が遅く、形成がみられない個体も観察された。無照射のりん片では基部に直接小球根が形成されたが、照射りん片ではカルスが形成されるものが多く、そのカルスから小さな球根が多数形成された。
Fig.2. Leaf color mutants induced by ion beam irradiation
これらのことから12C6＋での適正線量は0.2～0.4 Gyに、4He2＋
では1.5～2.0 Gy付近にあると推察された。
Reference

1) N. Chiba, et al., TIARA Annual Report 2005 (2006) 92.

－ 83 －

JAEA-Review 2007-060

3-18 Mutation Breeding on the Ornamental Plants of
Gypsophila and Gentiana Species
a)

a)

a)

b)

S. Tsuji , M. Miyamoto , T. Okabe , Y. Hase , Y. Yokotab)and I. Narumib)a)Oita General Service Co., Ltd.,b)Radiation-Applied Biology Division, QuBS, JAEA

Gypsophila paniculata and Gentiana trifida var. japonica are the important ornamental crops for cut flower use in Japan.
In an attempt to induce mutation for breeding use, shoots of such plants on LS medium were irradiated with carbon ion
beams using the JAEA AVF cyclotron. Irradiation experiments were conducted two times, and survival rates of theregenerated plants were evaluated when they were transplanted to the pots. The doses suitable for mutation induction are
estimated to be 2-4 Gy for Gypsophila and 0.5-1 Gy for Gentiana. Apparently, Gentiana is more susceptible to ion beamirradiation than Gypsophila.
較して、イオンビーム照射に対して感受性がより高い
ことが明らかとなった。

100
Survival rate (%)

花き類の宿根かすみそう・りんどうは切花用として栽培・出荷され、日本での作付面積は各々355および
508ヘクタールであり、農林統計において花き品目中5および4位に位置する重要な作物である。これらの花
き作物について、イオンビーム照射による新たな有用変異の誘発の可能性についての知見を得ることを目的とする。
有用変異誘発のための適正線量を検討するため、宿根かすみそう（品種｢ブリストルフェアリー｣）・りんどう（在来系統）のLS培地上の茎頂培養植物に、2006
年4月12日および6月12日の2回にわたり、日本原子力
研究開発機構イオンビーム照射研究施設（TIARA）のAVF サ イ ク ロ ト ロ ン を 用 い て 、 炭 素 イ オ ン ビ ー ム（12C6+, 320 MeV）の照射を行なった。照射後、培養を継続し、発根培地への植え継ぎ、ハウスへの順化、およびポットへの鉢上げを実施した。順化の際に、茎葉の奇形・生育不良などの異常率および生存率を調べた。また、ポットへの鉢上げ時にも生存率を測定し、照射線量との関係について調査した。

60
40
20
0
0

5

10

15

20

25

Dose (Gｙ)40
Survival rate (%)

宿根かすみそうにおける第1回の照射（線量0.5～
128 Gy）では、順化時の観察で8 Gy以上から徐々に奇形・生育不良などの異常率が増加した。32 Gy以上の照射でポットへの鉢上げまでに生存する個体はなかった。第2回照射（線量0.5～28 Gy）でも同様な結果が得られた(Fig. 1)。これらの照射試験で、順化および鉢上げ時において、8 Gyまでは高い生存率を維持していたが、16 Gyで急激に低下していた。したがって、有用
変異の誘発のためには、2～4 Gy照射が適正であると考えられた。このことは、すでに報告されている線量とも対応する1)。

Gypsophila

80

Gentiana
30
20
10
0
0

2

4

6

8

10

Dose (Gy)Fig.1 Survival rates of the plants regenerated from carbon
ion irradiated shoots of Gypsophila and Gentiana plants,
measured when they were transplanted to pots.

Reference
りんどうへの第1回の照射（線量0.5～128 Gy）で、培養期間中において、4 Gy以上の線量で低下していき、 1) M. Okamura et al. 2006 Ann. Rep. Res. Project with
Heavy Ions at NIRS-HIMAC (2007) 75.
それにともない、形態および葉緑体の異常率が明らかに高くなる傾向が認められた。8 Gy以上になると順化時までに枯死した。第2回照射（線量0.25～8 Gy）でも同様な結果が得られた(Fig. 1)。有用変異誘発には0.5～
1 Gy照射が適正であると結論した。
今回の研究で、りんどうは、宿根かすみそうと比－ 84 －

JAEA-Review 2007-060

3-19 Breeding New Varieties of Miniature Cymbidium
Using Ion Beam Irradiation
a)

a)

a)

a)

a)

S. Yuki , S. Araki , T. Suzuki , T. Ohsuga , K. Katayama , Y. Haseb)and Y. Yokotab)a)Central Research Institute, Ishihara Sangyo Kaisha, Ltd.,b)
Radiation-applied Biology Division, QuBS, JAEA

The protocorm like bodies (PLBs) of two novel varieties of miniature hybrid Cymbidium, which were bred by crossing
Cymbidium hybrida with Cymbidium goeringi, were irradiated with 320 MeV 12C6+ ions at various doses ranging from 0 to
128 Gy. Irradiated PLBs were cultured at 25 °C with a 16 hr photoperiod. After 12 months of culture, the efficiency ofregeneration from the PLBs was evaluated. In both varieties, it was drastically decreased at 16 Gy or more. Based on thisresult, we irradiated PLBs of three varieties of miniature hybrid Cymbidium at doses of 0-12 Gy in a mutation breeding
experiment.
（Fig.1）。ただし、128 Gyでも、約10%のPLBが再分化しており、本試験においては、照射サンプルの厚さにバラツキがあり、イオンビームが完全に透過していないサンプルが生じたことが想定された。
感受性検定試験２
試験１において、サンプルの厚さに懸念が生じたた
め、試験２においては、サンプル調製時に、2分割ではなく、削ぎ切りで厚さを1 mm程度に調整した。また、照射前の培養期間も短縮し、品種も2種追加した。これらの照射サンプルは、現在経過観察中であるが、これまでのところ、試験１とほぼ同様な経過を示している。ただし、やや感受性高くなっていると思われる。
変異誘発試験
感受性検定試験の結果から、変異誘発のための照射線量は16 Gy未満が適当と推定された。そこで、3種の小形シンビジウムのPLBに対して、12 Gy以下の10段階の線量で照射を実施した。今後、これらの照射サンプ
ルから再分化した個体を開花期まで栽培し、優良品種の選抜を試みる予定である。
120
Regeneration rate(%control)

はじめに
シンビジウムは、ファレノプシスやデンドロビウム
と共に、我国で最も重要なラン科園芸植物の一つとなっている。しかし、近年、業務用花卉需要の減少を受け、大型鉢物中心のシンビジウム市場は減少傾向にある。この市場の改善を目指し、石原産業㈱では、シンビジウムとシュンランの交配により育種された数種の小形シンビジウムを導入し、生産・販売することを検討している。この小形シンビジウムは、その大きさのため、交配による育種には制約がある。そこで、さらなる品種拡充のため、花卉育種で実績が高く、また、
シンビジウムでの変異体作出の報告1)のある、「イオンビーム育種」の本花卉への適用の検討を始めた。
材料および方法
感受性検定試験１2種の小形シンビジウム（S-26-9及びS-27-1）より調製したPLB（直径2～3 mm）をメスで2分割し、寒天培地上へ置床した。約1週間、25 ℃、16 hr照明下で培養後、炭素イオン（12C6+、320 MeV）を照射した。照
射線量は、0、0.5、1、2、4、8、16、32、64及び128Gyとし、一群50個の切片に照射した。照射サンプルは、新しい培地へ移植し、12ヶ月間培養した。その間に、出芽・発根したPLBを再分化したPLBとしてカウントし、
0 Gy照射群の再分化PLB数で除した値を各群の再分化率とした。
感受性検定試験２4種の小形シンビジウム（S-26-1、S-26-9、S-27-1
及びS-27-6）のPLBから厚さ1 mm程度の切片を調製し、寒天培地上へ置床した。1～5日間培養後、試験1と同様に炭素イオンを照射し、培養した。
変異誘発試験
3種の小形シンビジウム（S-27-1、S-27-6及びS-392）のPLBから厚さ1 mm程度の切片を調製し、寒天培地
上で3～4日間培養後、炭素イオンを照射した。照射線
量は、0、0.25、0.5、1、2、4、6、8、10及び12 Gyとし、一群100個の切片に照射した。
結果及び考察感受性検定試験１2種の小形シンビジウム共に、1 Gy以上の照射で、明確な線量依存的な生育抑制が観察された（データなし）。また、再分化率に関しては、8 Gyまでは僅かな低 下 の み だ っ た が 、 16 Gy 以 上 で 大 き く 低 下 し た

100

S-26-9S-27-1

80
60
40
20
0
0.1

1

10
Dose(Gy)

100

1000

Fig.1 Effect of ion beams on regeneration rate of PLBs
Reference
1) K. Furukawa, et al., イオンビーム育種研究会第2回大会要旨集.(2005)－ 85 －

JAEA-Review 2007-060

3-20 Study of Molecular Mechanism of Carbon Ion Beam
Induced Mutations in the Saccharomyces cerevisiae
a)

a)

b)

Y. Matuo , S. Nishijima , Y. Hase , A. Sakamotob)c)I. Narumi and K. Shimizub)b), Y. Yokota ,a)Graduate School of Engineering, Osaka University,
Radiation-applied Biology Division, QuBS, JAEA,
c)Radioisotope Research Center, Osaka Universityb)

The carbon ion beams were widely used as the mutagen
for breeding technology and also used for cancer therapy.
However, precise effect of ion beams to DNA molecules has
not been elucidated.
The molecular mechanism of the mutagenesis caused bycarbon ion beams was studied. The mutation sites caused byion beams were determined and the mutation spectrums
were compared with those induced by gamma ray.
S. cerevisiae strains used in this study were S288C(RAD+), rad50 and rad52. RAD50p is a component of thenonhomologous end joining repair pathway. RAD52p is acomponent of the homologous recombination repair
pathway.
The yeast cells were irradiated with carbon ions (12C5+;220 MeV) with the dose 10 to 300 Gy, and LET was 107
keV/µm. Carbon ion beams were generated from AVF
cyclotron in JAEA. The survival rates following irradiation
were determined on the basis of colony-forming ability. And,selection of ura3 cells was accomplished by plating the cellson the media containing 5-fluoroorotic acid1). The mutationsites of ura3 mutants were determined by DNA sequencing.
Figure1 shows the survival rates of several strains
exposed to 12C5+ ion. rad50 and rad52 cells showed highsensitivity to ion-beam (Fig.1).

The URA3 regions (804 bp) were sequenced. Fig.2 shows
the mutational spectrums of irradiation ion beam andgamma ray. The remarkable feature of mutations in wild
type cells induced by carbon ions was that the mutations
sites were localized near the linker regions of nucleosomes2).
On the contrary, the mutations were induced in the DNA
region which combined with the histone-protein in rad50 or
rad52 strain (Fig.2). This difference may result from therepair pathway which operates in mutant strains.
Moreover, the GC → TA transversion was largely
observed. It suggests that the mutations by ion beams
resulted from oxidative damage such as formation of
8-oxodGTP mainly2-3). To elucidate the ion beam effect on
the budding yeast, we are going to analysis ogg1 and msh2
mutant strains which are deficient in oxidized purine baselesion DNA N-glycosylase activity and mismatch repair
activity, respectively.
References
1) D. Burke, et al., Cold Spring Harbor Laboratory Press(2000) pp7-15
2) Y. Matuo et al., Mutat. Res. 602 (2006) pp7-13.
3)
P. M. Girard et al., Carcinogenesis. 19 (1998)
pp1299-1305
MNase active site

Fig. 1. Survival curves for yeast strain S288c after
irradiation with carbon ion beams.

Fig. 2. Mutational spectrum of irradiation ion beam(above) and gamma ray (below).

－ 86 －

JAEA-Review 2007-060

3-21 Mutation Induction in Azalea Using Ion Beam
Irradiation and Its Gene Analysis
a)

a)

a)

N. Kobayashi , S. Sakamoto , A. Nakatsuka , Y. Haseb)

and I. Narumib)a)Faculty of Life and Environmental Science, Shimane Universityb)
Radiation-Applied Biology Division, QuBS, JAEA

Introduction
In this study, ion beams were irradiated to azalea seeds
and cultured leaf segments to induce flower color and shapemutation. Additionally, we try to research the key genes ofion beam induced mutations as a final purpose; anthocyanin
biosynthesis genes related to flower color mutation andhomeotic genes related to flower shape and organ mutationthat we already isolated 1),2).
2. Materials and Methods
2-1．Seeds of Rhododendron kaempferi, R. ripense, R.
japonicum and R. matternichii var. brevitolium were
irradiated with carbon ion beam (220 MeV 12C5+) at 0 to 50
Gy（Fig. 1). After the irradiation, seeds were sowed on
sphagnum moss bed in pot. The germination rate was
evaluated after 6 weeks.
2-2 ． Young leaves of potted R. × pulchrum ‘Sen-eoomurasaki’ were excised, sterilized and used as explants
materials as previous study3). The leaf segments were
cultured on modified 1/2 Murashige and Skoog’s medium
supplemented with 2 μM NAA and 9 μM TDZ in the test
tube4). The explants were transplanted on the highconcentration agar medium in the tissue culture dishes andcovered with Kapton film. The transported samples were
irradiated with carbon ion beam (220 MeV 12C5+) at various
doses (0 to 128 Gy, Fig. 2 ). The leaf segments weretransplanted on the initial medium and cultured at 22±1 °C
with 16 hours-photoperiod after the irradiation. The
regeneration rates of callus, shoot primordia and shoot were
investigated after 2 months.
Germination rate （%）

1.

100
80

R. kaempferi

60

R. ripense

40

R. japonicum

20

R. matternichii

3.

Results and Discussion
3-1．In preliminary experiment, seeds of 5 species were
irradiated with carbon ion beam at ranges from 0 to 100
Gy5). These seeds were difficult to germinate with ranges
more than 60 Gy irradiation. Therefore, the second
irradiation was applied narrow doses (0 to 50 Gy) in thesame condition (Fig. 1). The germination rates werestrongly downed at the ranges from 30 to 50 Gy anddifferent depending species. The optimal irradiation doses
for seeds considering from median germination decrease
may be 30 to 40 Gy for R. kaempferi, 20 Gy for R. ripense,
10 to 20 Gy for R. japonicum and 20 to 30 Gy for R.
matternichii var.brevitolium.
3-2．The regeneration rate of callus decreased according
to the ion beam strength from 8 Gy irradiated leaves (Fig. 2).
While, shoot primordia and shoot were not able toregenerate with more than 8 to 16 Gy irradiation (Fig. 2, 3).
The effective conditions to obtain irradiated mutants were
thought to be from 4 to 8 Gy exclusive for R.×pulchrum‘Sen-e-oomurasaki’ leaves. Mutation research will
determine plants regenerated from these shoot primordia
and shoot of ion beam irradiation.
4. References
1) D. Mizuta et al. 2007. Abst. Chugoku-Shikoku Br., Japan.
Soc. Hort. Sci. 46 (2007) 44 (In Japanese).
2) M. Ohtani et al. Hort. Res. (Japan) 6 Suppl.1 (2007) 458(In Japanese).
3) N. Kobayashi et al. JAEA-Review 2006-042 (2007) 96.
4) S. Sakamoto et al. J. Japan. Soc. Hort. Sci. 74 Suppl.2(2005) 310 (In Japanese).
5) S. Sakamoto et al. Abst. Chugoku-Shikoku Br., Japan.
Soc. Hort. Sci. 46 (2007) 39 (In Japanese).

0
0

10

20
30
Dose (Gy)40

50

Fig. 1 Dose response of germination rate in 4 species
at 6 weeks after sowing.
Regeneration rate（%）

100

0Gy

2Gy

4Gy

8Gy

16Gy

32Gy

64Gy

128Gy

80
callusshoot primodia
shoot

60
40
20
0

cont

0

2

4

8
Dose（Gy)

16

32

64

128

Fig. 3Fig. 2 Regeneration rates of callus, shoot primordia andshoot from R.×pulchrum ‘Sen-e-oomurasaki’ leaf
segments at 2 months after irradiation.

－ 87 －

Dose response of regeneration from R.×pulchrum‘Sen-e-oomurasaki’ leaf segments at 2 months after
irradiation.

JAEA-Review 2007-060

3-22 Effects of Ion Beam Irradiation on Plant Growth andMorphology in Soybeana)a)A. Kanazawa , J. Abe , Y. Hasea)b)

and A. Tanakab)b)Research Faculty of Agriculture, Hokkaido University, Radiation-Applied Biology Division,
QuBS, JAEA

Soybean (Glycine max) is an important crop in terms of
production of food, oil, and forage. However, existing
mutant lines of soybean ave very limited, which is aconstraint on performing genetic study and breeding of thisplant. One of the reasons for the small number of mutant
lines in soybean appears to be associated with difficulty inproduction of a mutant and to duplication of genomic
segments. This plant is considered to have derived fromancestral plant(s) that have a tetraploid genome, and as aconsequence, more than 90 % of nucleotide sequence in thesoybean genome is duplicated1), 2). It is conceivable thatsuch a duplicated nature of the genome brought about a low
frequency of mutant production by conventional methods
for mutagenesis such as γ-ray or X-ray irradiation as well as
chemical treatments. In these circumstances, we have started
to examine whether ion beam irradiation is effective in
producing a mutant in soybean because ion beam irradiation
is expected to cause genomic changes that are more drastic
than those induced by conventional mutagenesis.
Dried seeds of soybean were exposed to the 320 MeV
carbon ions with a range of 0.2-25 Gy. In order to irradiate
at an equal dose on seeds, seeds were fixed on a plastic dishin which meristem tissues were positioned on the top (Fig.
1). The irradiated seeds were sown on soil and plants weregrown for three weeks in a green house. A prominent
decrease in plant height was observed depending on thedose in the range of 5-25 Gy (Fig. 2), but not in the range
lower than 5 Gy (0.2, 0.5, 1.0, and 2.0 Gy; data not shown),

indicating that doses higher than approximately 5 Gy affectplant growth rate.
In addition to the inhibition of plant growth,morphological changes were also induced by irradiation.
One of the prominent changes in morphology was detectedin the primary leaves in which a narrow portion was
generated in the central part of a leaf. This type of change
was detected in 15 plants per 66 plants irradiated at 5 Gy,
and in 4 plants per 56 plants irradiated at 2 Gy. The otherprominent morphological change was unscheduled
generation of stem(s) from the node where cotyledons wereformed (Fig. 3). This type of change was detected in 8
plants per 66 plants irradiated at 5 Gy, and in 2 plants per 56
plants irradiated at 2 Gy. Both types of change were notdetected in plants irradiated at the doses lower than 1 Gy.
Based on the observed effects of irradiation at various
doses on plants, we concluded that irradiation at 2-5 Gy is
most appropriate for producing mutant population in ourmaterial. We subsequently performed a large-scale
irradiation to soybean seeds at the doses of 5 Gy and 2.5 Gy
to 3,200 seeds and 3,320 seeds, respectively, and grew themin the field of Hokkaido University. We are currently
analyzing the effects of irradiation using field-grown plants.
References
1) R. C. Shoemaker et al., Genetics 144 (1996) 329.
2) H. Zhu et al., Plant Physiol. 137 (2005) 1189.

Plant height (cm)

10
8
6
4
2
0
0

5

10

20

30

40

Dose (Gy)Fig. 1 Soybean seeds placedon a dish for irradiation.

Fig. 2 Growth of plants after
irradiation at the doses of 5-40
Gy. Average ± SE are shown.

－ 88 －

Fig. 3 An altered phenotype ofplants as a consequence of
irradiation. Left, control plant;
right, plant exhibiting alteredmorphology.

JAEA-Review 2007-060

3-23 Mutation Induction by Carbon Ion Beam
Irradiation in Banana (Musa spp.)
W. O. Reyes-Borja a) , I. Sotomayor b) , I. Garzón, D. Vera b) ,M. Cedeño b) ,A. Tanaka c) , Y. Hase c) , Y. Sekozawa a) , S. Sugaya a) and H. Gemma a)Life and Environmental Sciences, University of Tsukuba,b)
Estación Experimental Tropical Pichilingue, Ecuador,c)
Radiation-Applied Biology Division, QuBS, JAEA
the candidate plants, field experiments based on thewhole plant cycle are necessary to evaluate not only the
response to black Sigatoka disease but also fruit quality,
potential production and post-harvest parameters as
valuable components for final selections.

BA

Fig 1. A. Hexaploid cells (encircled) in ‘C. Enano’
produced by ion beam dose 4 Gy. B. ‘C. Enano’ at 4 Gy
showing a fast growth (in the center).
Williams

100

A

LDNA-%

80

y = 1. 3 19 5 x + 1. 6 6 4 4
R 2= 0 . 2 4 55

60
1

40

2
3

4

5
6

20
25

30

35

40

45

50

55

II-%

100

B

y = - 1. 9 7 0 6 x + 14 7 . 6 9
R 2= 0 . 12 9 380
LDNA-%In Banana (Musa acuminata AAA), most research
focuses on generating cultivars tolerant/resistant to black
Sigatoka disease caused by Mycosphaerella fijiensis
Morelet which is the most dangerous disease distributed
worldwide. Ion beams radiation breeding permitted us toselect some candidates plants at the nursery condition
showing some tolerance against to this disease; however,others interesting characteristics were also observed.
The irradiation was conducted at the Takasaki Ion
Accelerators for Advanced Radiation Application(TIARA), Japan Atomic Energy Agency (JAEA). Carbon
ion beams irradiation was applied on in vitro explants ofbanana cultivars ‘Cavendish Enano’ and ‘Williams’ withthe dose of 0, 0.5, 1, 2, 4, 8, 16, 32, 64 and 128 Gy.
Recorded data were: survival rate (%), relative DNAcontent (by flow cytometry), leaf disc necrotic area
(LDNA-%) under the juglone toxin inoculation, diseasedevelopment period (DDP-days) and infection index(II-%) by using the fungus of Mycosphaerella fijiensis
Morelet for inoculation.
Regarding to the survival rate (%) in general terms, thehigher irradiation dose resulted in higher mortality rate,
but doses of 8 Gy and lower did not seem to have any
effect on survival rates. The flow cytometer analysis
detected hexaploid cells among the samples (Fig. 1A).
‘Cavendish Enano’, and ‘Williams’ reported 5 and 1
hexaploid plants, respectively at 4 Gy. This could be away of causing chromosome duplication, efficiently andfast, especially on improved diploids possessing
resistance that could be used as parental lines for banana
breeding. A fast growing plantlet (Fig. 1B) was also
observed among the irradiated cultivar which is a very
important characteristic as it may result in earliness offruit harvesting.
For selecting tolerant/resistant plants to black Sigatoka,
the variables DDP-days, II-% and LDNA-% werecombined by linear regression to categorise the responseto black Sigatoka in the irradiated materials. LDNA-%
regression versus II-% showed high significance (p ≦0.01) compared with LDNA-% versus DDP-days, and
DDP-days versus II-% that were significant at the 5%
level (p ≦ 0.05) in ‘Williams’ (Fig. 2). Six plants in‘Williams’ and two plants in ‘Cavendish Enano’ wereselected as candidates with increased tolerance to black
Sigatoka disease. Regarding the complete assessment of

60
1

40
3

6

4

2

5

20
38

41

44

47

50

53

56

45

50

55

DDP-days

60C

y = - 0 . 18 0 3 x + 5 4 . 3 17
R 2

55
DDP-daysa)= 0 . 13 6 2

1
2

50

3

5
4
6

45
40
35
25

30

35

40
II-%

Fig. 2. LDNA-% regression versus II-% (A), LDNA-%
regression versus DDP-days (B) and DDP-daysregression versus II-% (C) in ‘Williams’. Encircled boldand numbering triangles belong to the selected candidate
plants that clearly show relationships.

－ 89 －

JAEA-Review 2007-060

3-24 Effect of 12C6+ Beam Irradiation on Callus Formationand Shoot Regeneration from Isolated Cultured Cells in
Lavandula x intermedia Emeric.
a)

a)

a)

M. Tsuro , S. Daimyo , T. Takeda , Y. Yokotab)and Y. Haseb)a)Faculty of Agriculture, Meijo University
Radiation-Applied Biology Division, QuBS, JAEAb)

In order to develop a new lavandin, Lavandula x intermedia Emeric., plant with different fragrance from original plant,
effect of several doses of 12C6+ beam on callus formation and shoot regeneration from isolated cultured cells was analysed.
Growth index (GI) of callus proliferation was decreased with increase of irradiation dose. RD50 in GI of callus proliferation
was estimated between 64.0 to 128.0 Gy. On the other hand, RD50 in shoot formation rate was determined among 2.0 to 4.0
Gy, lower than that in GI of callus proliferation. These results suggested that RD50 in GI of callus proliferation and shootformation rate were different. However, any regenerated plants were not obtained from shoots. Further analysis is now
conducted to obtain regenerated plants from shoots.
ラベンダーのエッセンシャルオイルは多くの化合物で構成されており、その成分比の違いにより香調が大きく変化することから新しい香りの創出が期待されている。
本研究では、 12C6+ ビームの照射により、エッセン
シャルオイル成分比が親植物体と大きく異なり香調が変化した変異体の作出を目的として、12C6+ビームの線量がラベンダー培養細胞の増殖および不定芽の形成に及ぼす影響を調査した。
植物材料としてラバンジン（真正ラベンダーとスパ
イクラベンダーとの雑種）品種‘スーパーセビリアン
ブルー’を用いた。0.2 mg/l 2,4-Dと0.2 mg/lカイネ
チンを添加したMS固形培地で誘導した葉由来カルスを同組成の液体培地で振盪培養し、得られた懸濁培養細胞を細胞密度が2×105個/mlとなるように調整した。カ
ルス培養と同組成の固形培地を入れた直径6 cmのプラ
スチックシャーレに細胞懸濁液を0.5 ml分注し、320
MeV 12C6+ビームを0, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0,
32.0, 64.0および128.0 Gyの線量で照射した。照射後、25℃、暗条件で培養を行い、4週間後に増殖したカルスの大きさを0から5の6段階で評価した。評価後、カルスを1mg/l BAを添加したMS固形培地に移植して25℃、明条件で培養し不定芽の誘導を試みた。実験は4回反復で行った。
培養１ヶ月間後のカルスの増殖程度を評価したとこ
ろ、0 Gy区ではカルス形成が見られない培地は認められなかったものの、増殖指数(GI)は1から5までとばらつきが見られ平均指数は2.7であった。0.5 Gy区および1.0 Gy区も0 Gy区とほぼ同様の指数を示していたが、2.0 Gy以 上 で は 全 く カ ル ス の 形 成 が 認 め ら れ な い

シャーレも見られ、線量の増加に伴って平均指数が低下した。さらに、128.0 Gy区では細胞のカルスの形成が全く認められず、ラバンジン培養細胞では64.0 Gy～128.0 Gyの間に致死線量があることが推察された。
カルス増殖指数を指標した増殖反応曲線をもとに0 Gyの半分程度の増殖指数を示す線量（半増殖線量（RD50 ））を探索したところ、16.0 Gyから32.0 GyにRD50があることが示唆された（Fig.1）。
一方、増殖したカルスをシュート誘導培地に移植した後、約1ヶ月培養をしたとき、カルスからシュートの形成が認められた。Table 1にシュート誘導培地で1ヶ月間培養したときのカルスの生存率およびシュート形成率を示した。0 Gy区では、12.5％のカルスがシュートを形成しており、2.0 Gyまで同程度のシュート形成率で、1.0 Gy区において、24.1％と最も高い
シュート形成率が認められた。2.0 Gyを超える線量では、カルス増殖と同様に線量の増加に伴ってシュート形成率が低下し、32.0 Gyおよび64.0 Gyのカルスからは全くシュートが形成されなかった。このことから、
0～2.0 Gy区での平均シュート形成率を基準としたときの半シュート形成線量（RD50 ）は、2.0 Gy～4.0 Gyの間にあることが推察された。しかしながら、全ての線量区で誘導されたシュートの多くが、伸長途中に枯死したため、効率的な変異体獲得には今後より詳細な培養条件の検討が必要であると思われる。
Table 1. Influence of 320 Mev 12C6+ beam irradiation on shootformation from isolated cells-derived callus in lavandin
No. ofcultured callus

No. of survived
callus (％)

No. of shootformed callus (％)

056

28 (50.0)

0.5

59

36 (61.0)

6 (10.2)

1.0

58

39 (67.0)

14 (24.1)

1.5

2.0

59

35 (59.0)

8 (13.6)

1

4.0

51

27 (53.0)

4 (7.8)3
2.5
Growth Index (GI)

Dose (Gy)

2

0.5
0

0

0.5

1.0

2.0

4.0 8.0 16.0 32.0 64.0 128.0
Dose （Gy)Fig.1 Effect of 320 MeV 12C6+ beam irradiation on proliferation ofcultured isolated cells in lavandin. (■); Average number of
GI on a given dose, (…) ; Fitted curve for line graph.

－ 90 －

7 (12.5)

8.051

29 (57.0)

4 (7.8)16.0

47

28 (60.0)

2 (4.3)32.0

21

1 (5.0)

0 (0)

64.0

3

0 (0)

－

JAEA-Review 2007-060

3-25 Screening of Higher Astaxanthin Producing Mutants of aGreen Unicellular Alga Haematococcus pluvialis by Ion
Beam Irradiation
T. Kakizono , T. Sugiura , R. Yoshihara , Y. Hase , I. Narumi

a)

a)

b)

b)

b)

a)

b)

and A. Tanakab)

Department of Molecular Biotechnology, AdSM, Hiroshima Univ, Radiation-Applied
Biology Division, QuBS, JAEA

A highly anti-oxidative ketocarotenoid, astaxathin has been produced by culturing a unique green unicellular alga H.
pluvialis in large-scale photobioreactors at rich solar energy areas such as Hawaii islands. Since it seems disadvantageous tocarry out the algal culture phototrophically in a commercial basis in Japan, we have applied heterotrophic cultivation for thealga. In the dark condition, the alga was found to have a very limited carbon source specificity, namely acetate, and produce
astaxanthin about one-third of the phototrophic condition (20 mg-astaxanthin/l) as the cellular content basis (2% w/w). In
this study, we have examined the possibility of ion beam irradiation technology for the alga to obtain higher astaxanthin
producing mutants, and also high tolerant mutants to acetate. Firstly, the dose effect of ion beam was studied for two culture
conditions. In addition, several algal cell preparation techniques including filtration on paper, glass wool, or nitrocellulose,
and spreading directly on agar were tested for the better cell recovery.
かとなった。さらに、基質である酢酸は50mMを越える
高度に抗酸化力を有するアスタキサンチン(以下と増殖阻害が起きるので、細胞の高濃度化の障害とな
ASX)は、ほとんどの種類の甲殻類，サーモンの肉色，る。そこで、イオンビーム変異導入法により、緑藻ゲ
タイの体表皮など海洋生物に広く分布するケトカロテ
ノイドである。近年、体内で必然的に発生する活性酸
100%
素が種々の疾病，老化，発ガン作用に関与するとの報100%
告があるので、食品やサプリメントとして抗酸化作用80%が注目され、特にASXについては、疲れ目予防，ロー61%
60%
ション，健康飲料など様々な用途に利用されるように
なった。
40%
33%
微 細 緑 藻 H. pluvialis は 分 裂 増 殖 す る 栄 養 細 胞
20%12%(Fig.1左)においてカロテノイド色素は少量であるが、
3%
0%
0%
0%
0%
栄養条件の悪化とともにシスト細胞と呼ばれる胞子嚢
0%
0
5
10
20
40
80 160 320 640細胞(同,右図)へ形態変化し、ASXを細胞重量比で2-3%Gyの著量に生成する1)。
Fig.2 Effect of ion beam irradiation on the green algalcolony formation.

Fig.1 Morphological change from vegetative cells (left)to cyst cells (right)of H. pluvialis, and massive
astaxanthin formation in cyst cell.
太陽光を用いた大規模培養が、年間を通して良好な晴天が得られる地域（米国ハワイ諸島，中国昆明等）で行われているが、閉鎖系・開放系を問わず、雑菌汚染，温度・日照時間変動など農業に類似する問題があり、安定な生産系ではない。
そこで、われわれは本緑藻が、太陽光に依らずに暗所で酢酸を炭素源に従属栄養的に増殖し、ASX生成を行いうることに着目し、その大規模生産の可能性を検討すべく、形態変化を伴わせたASX生産条件、および基質種と濃度効果を調べた。その結果、ASX含量は光培養系に匹敵するものの、細胞濃度が上がらず、また基質には酢酸とピルビン酸しか使えないことが明ら

ノム(近縁種の Chlamydomonas では110Mb)に染色体レ
ベルの分断と再編成をもたらすことによって、従属栄
養条件で旺盛に増殖し、ASXを高含量に生成する変異株または、酢酸耐性変異株等を広範囲にスクリーニン
グ・単離することを目的に、イオンビームの線量について、様々な培養条件で調製した栄養細胞，シスト細胞を、ろ紙，あるいはグラスウールフィルタを用いてろ過下細胞、または寒天培地に直接細胞を高濃度に塗布したものを照射試料として、変異致死率(Fig.2)、
変異細胞調製と細胞回収の効果を検討してきている。
References
1) 杉浦俊浩ら “単細胞緑藻Haematococcus pluvialisの従属栄養培養におけるアスタキサンチン生成の検討”, 第59回日本生物工学会大会要旨集 ID10-3, p60(2006).
2) Kobayashi, M et al. “Enhanced carotenoid biosynthesisby oxidative stress in acetate–induced cyst cell of a green
unicellular alga, Haematococcus pluvialis.,”., Appl.
Environ. Microbiol. 59, 867–873 (1993).

－ 91 －

JAEA-Review 2007-060

3-26 Role of LexA2 in Radiation Response Mechanism ofDeinococcus radioduransa)a)K. Satoh , H. Ohba , H. Sghaiera)a), b)and I. Narumia)b)

Radiation-Applied Biology Division, QuBS, JAEA, Department of Biological andChemical Engineering, Faculty of Engineering, Gunma University

Introduction
RecA and LexA proteins in Escherichia coli play
important roles in the inducible DNA damage response andrepair mechanism (the SOS system).
Following DNA
damage, RecA is activated by binding to single-stranded
DNA which is generated by DNA damage. The interactionof activated RecA and LexA results in the proteolytic
cleavage of LexA.
RecA-mediated cleavage of LexA
inactivates LexA as a repressor. Consequently, various DNA
repair genes controlled under LexA are derepressed, thereby
the intracellular levels of various DNA repair proteins
including RecA are transiently increased.
Although the radioresistance bacterium Deinococcus
radiodurans possesses LexA1 protein which resembles E.
coli LexA protein, LexA1 is not involved in induction of
DNA repair proteins following DNA damage1).
Bioinformatic analysis of the D. radiodurans genome
sequence showed that the genome encodes a second,
diverged copy of LexA1, named LexA2. In an effort to gain
an insight into the role of LexA2 in the radiation response
mechanism, recA, lexA1 and lexA2 disruptant strains weregenerated, and the sensitivity to γ-rays, the expression ofradiation inducible DNA repair gene and the changes inintracellular level of protein following irradiation were
investigated.

1, the lexA2 disruptant and lexA1 lexA2 double-disruptant
strains exhibited a much higher resistance to γ-rays than thewild type and lexA1 disruptant strains. Since the decrease in
the intracellular LexA1 level reflects the co-protease activityof activated RecA, the recovery to a basal level of LexA1
indicates the inactivation of RecA. The inactivation of RecA
was faster in the lexA2 disruptant strain than in the wild typestrain. Given that the inactivation of RecA is associated withthe completion of DNA repair, the DNA repair capacity
might be enhanced in the lexA2 disruptant strain relative tothe wild type strain.
Furthermore, pprA promoter activation was enhanced in
the lexA2 disruptant strain following γ irradiation. The pprA
gene encoding the novel radiation-inducible protein PprA
plays a critical role in the radioresistance of D. radiodurans6).
The increase in radioresistance of the lexA2 disruptant strain
is explained in part by the enhancement of PprA functions7).
References
1) I. Narumi et al., J. Bacteriol. 183 (2001) 6951.
2) T. Funayama et al., Mutat. Res. 435 (1999) 151.
3) H. Nishida et al., Microbiology 148 (2002) 2911.
4) H. Ohba et al., Gene 363 (2005) 133.
5) K. Satoh et al., J. Biochem. 131 (2002) 121.
6) I. Narumi et al., Mol. Microbiol. 54 (2004) 278.
7) K. Satoh et al., Microbiology 152 (2006) 3217.

Experimental procedures
Gene disruptants were generated using directed insertionalmutagenesis technique that was developed by our group2, 3).
D. radiodurans cells were resuspended in 10 mM sodium
phosphate buffer. The cell suspension was irradiated with
60
Co γ-rays at dose rates from 0.1 to 5 kGy/h at Food
Irradiation Facility, JAEA. The gene expression and thechanges in intracellular level of protein were analyzed bydual luciferase assay4) and western blotting method5),
respectively.
Results and discussion
Like LexA1, LexA2 was cleaved by activated RecA toproduce two breakdown products. The intracellular level of
LexA2 in the recA disruptant strain did not change following
γ irradiation, indicating that RecA is the sole protein requiredfor LexA2 cleavage.
RecA induction following γ irradiation was also observedin the lexA2 disruptant and lexA1 lexA2 double-disruptant
strains, clearly indicating that neither LexA1 nor LexA2 isinvolved in RecA induction. Interestingly, as shown in Fig.

－ 92 －

Fig. 1 Survival curves for γ rays. Symbols: closed
circles, wild type; open squares, lexA1 disruptant
strain; open triangles, lexA2 disruptant strain; closed
lozenges, lexA1 lexA2 double-disruptant strain.

JAEA-Review 2007-060

3-27 Analysis of Mutagenic Effect Induced by Ion Beams for
Breeding of Aspergillus oryzae
a)

a)

a)

b)

b)

Y. Toyoshima , T. Akagawa , T. Yamazaki , K. Satoh , Y. Hasea)and I. Narumib)b)

Soy Sauce Laboratory Manufacturing Division, YAMASA CORPORATION, Radiation-Applied
Biology Division, QuBS, JAEA

In this study, we investigated the mutagenic effect induced by ion beams for breeding of A. oryzae, which is used in the
manufacture of traditional Japanese fermented foods, such as soy sauce, sake and miso. We irradiated A. oryzae with 220
MeV carbon ions by AVF cyclotron at the doses of 300-700 Gy. Mutation rate was measured by counting the number ofselenic acid resistant colonies whose mutation relates to sB and sC genes that are involved in sulfur incorporation. These
analyses indicated the suitable dose for obtaining variants to be 400 Gy. Furthermore, PCR analysis suggested 57 % of
these variants carry a deletion with sC or sB gene under this condition.

【結果】
生存率については線量が大きくなるに従って低下した。また、線量ごとの変異率は 400 Gyで最大を示した（Fig. 1）。次に、得られた変異株の変異パターンを解析した。変異株のゲノムを抽出しPCRを行ったと
ころ、遺伝子の前半領域のみ、もしくは後半のみが増幅されるもの、両方とも増幅されないものなど、欠損変異を示唆するデータが得られた。これらの株の割合

Dose (Gy)

0

300

400

500

600

700

1.E+000.08
survival rate

1.E-01mutation rate

0.07
0.06
0.05

1.E-020.04
1.E-030.03
0.02

1.E-04m u t a t io n r a t e (% )【実験方法】
・サンプル調製および照射条件
A. oryzae (niaD300)の分生子を凍結乾燥し、照射
サンプルとした。照射はTIARAのAVFサイクロトロンを用いて加速した 12C5+ （220 MeV, 107 keV/μm）により行った。
・生存率と変異率
生存率はイオンビームを300～700 Gy 照射したサン
プルを栄養培地に播種し、生育したコロニー数から生存率を求めた。
イオンビーム照射サンプルをメチオニン 30 ppm,
セレン酸 0.1 mM を含む最少培地に播種し、得られたセレン酸耐性株の数から変異率を求めた。
・変異箇所の探索
硫黄の取り込みに関与するsB遺伝子、sC遺伝子が変異することによりセレン酸耐性になることが知られている 1) 。 sB 、 sC の前半、後半領域の各断片を増幅する
プライマーを設計し、遺伝子欠損の有無についてPCR
により検討した。

を求めたところ、全耐性株の 27％ほどを占め、高い確率で遺伝子欠損株が得られることが示唆された。また、400 Gy照射区では欠損変異を示唆する株の割合が57％であり、他の照射区に比べ極めて高い割合であった（Table 1）。
以上のことから、凍結乾燥処理を行った麹菌のイオ
ンビーム照射では 400 Gy程度の線量で高い変異効果が期待でき、遺伝子の欠損変異が高い割合で生じていることが示唆された。

s u r v iv a l r a t e (l o g)

【緒言】
麹菌（Aspergillus oryzae）は醤油、清酒、味噌などの醸造産業において利用される重要な微生物である。
そのため古来より麹菌の育種が精力的に行われてきた。
近年、植物などの育種においてイオンビームが注目されており、その変異効果が従来の変異原に比べて高く、変異スペクトルも様々であることが報告されている。そこで我々は、麹菌育種の新しい手段としてイオ
ンビームの利用を検討することとした。麹菌へのイオ
ンビーム照射についてのデータはまだ少数であることから、まず、照射条件や変異効果について検討した。

0.01
1.E-05

0.00

Fig. 1 Survival rate and Mutation rate of conidia
after irradiation with ion beams in A.oryzae.
Table 1 Difference in mutagenic effect at various dosesof ion beams in A.oryzae.
Dose （Gy）

0

300

400

500

600

700

Survival rate （％）

100

4.13

0.31

0.08

0.03

0.01

Mutation rate (％)

0

0.026

0.070

0.055

0.018

0.009

No. of variants (cfu)

0

12

21

11

5

2

No. of deficient strain(cfu)
Percentage of deficientstrain per variants (％)

0

1

12

1

0

0

0

8.3

57.1

9.1

0

0

Reference
1) O. Yamada et al., Biosci. Biotechnol. Biochem. 61(1997) 1367.

－ 93 －

JAEA-Review 2007-060

3-28 Mutation Breeding of Koji Mold Induced by Ion Beam
a)

a)

a)

b)

K. Ito , J. Takeichi , Y. Hanya , K. Satoh , Y. Hasea)b)

and I. Narumib)b)

R&D Division, Kikkoman Corp., Radiation-Applied Biology Division, QuBS, JAEA

Introduction
Koji molds, Aspergillus sojae and Aspergillus oryzae, areindustrially important microorganisms which is used for
brewing of soy sauce. The various mutagens have beenused for mutation breeding of koji molds for many years.
However, there are problems in usual mutagens, forexample UV, NTG and X-rays lead to much inconvenientmutation such as slow growth rate and poor conidiation.
Consequently, most mutants simultaneously have these traits,even if target trait was acquired. Therefore, we focused on
mutation by ion beam. It is known that this method
induces targeted mutations with smaller number ofinconvenient mutation.
We previously reported thatsurvival rate and mutation frequency of A. sojae IFO4241
following irradiation of ion beams and determined optimal
irradiation conditions1). In this report, we investigatedwhether ion beams induce deletion mutations in A. sojae
IFO4241 as well as higher plants. A defect in the wA geneof Aspergillus species is associated with the loss of conidial
pigmentation and the conidial color of this mutant will turnto white from green2). To investigate the deletion mutation
frequency, the pigmentless-conidium mutants were obtained
and the wA gene of these mutants were analyzed.
Materials and Methods(1) Isolation of pigmentless conidium-mutants
The suspension containing 106 conidia (A. sojae
IFO4241) were spread on Malts agar plate and incubated at
30 ºC for 6 hr for germination. Germinated conidia were
irradiated with 220 MeV 12C5+ (121.8 keV/μm) ion beam
accelerated by AVF cyclotron at TIARA with the dose of100, 150 and 200 Gy. Irradiated conidia were cultured at
30 ºC for 3 days. The pigmentless-conidium mutants were
picked up and purified three times by single conidium
isolation on Malts agar plate containing 0.25 % Triton
X-100. UV irradiation was performed as previously
described1). Only one mutant was picked up from each
irradiated plate.
(2) DNA analysis of wA gene of pigmentless-conidium
mutants
The full length of genomic wA gene from pigmentlessconidium mutants and/or their internal regions were
amplified by PCR using various primer sets.
The
amplified DNA fragment size was compared with that ofwild type on 0.8 % agarose gel. Southern blot analysis was
performed using DIG labeling Kit (Roche). The PCR
fragment of wA gene was used as a probe for southern
analysis.
Results and Discussion
The number of pigmentless-conidium mutants from
irradiated plates with ion beam and/or UV was 114 and 38,

respectively (Table 1). The full-length wA gene (8.0 kb) ofpigmentless-conidium mutants was amplified by PCR using
primer F1 and R2 (Fig. 1). We evaluated the deletion
mutation of wA gene if the PCR fragment was not amplified(Fig. 1 (B)-(D)) or the amplified PCR fragment size wassmaller than that of wild type (Fig. 1 (A)). Out of 114
pigmentless-conidium mutants with ion beam irradiation, 38
mutants were deletion mutant (Table 1). On the other hand,
all pigmentless-conidium mutants with UV irradiation were
not due to deletion mutation. These results indicated that
deletion mutation frequency with ion beam irradiation was
higher than that with UV irradiation. PCR analysis of 38
deletion mutants revealed that the deletion mutation wasclassified into four patterns (Table 2 (A)-(D)). The loss ofwhole wA gene of pattern C mutants was confirmed bysouthern blot analysis (data not shown). This result
revealed that an 8.0-kb chromosomal region could bedeleted with ion beam irradiation in A. sojae IFO4241.
The large deletion mutation might be occurred in A. sojae
IFO4241 as well as higher plants.
Table 1 Comparison of deletion mutation frequency between
ion beam irradiation and UV irradiation.
Number ofirradiatedplatesNumber ofpigmentlessmutants

Number ofdeletionmutants

Deletion mutants per
pigmentless-conidium
mutants (%)

Ion beam

144

114

38

33

UV

120

38

0

0

F1

Pimer sets

F2

R1
R2
Mr Wt (A) (B) (C) (D) Mr

F1-R2
F1-R2
(Deleted)
pyrG
F1-R1

Wild type
(Wt)

F2-R2

Pigmentlessconidium
mutantFig. 1 PCR analysis of the wA gene of deletion mutants.
The pyrG gene was amplified as a positive control.
The lane Mr is DNA size marker.
Table 2 The mutation pattern of wA gene in deletion mutants.
M u tatio n p a ttern

N u m b er ofm u ta n ts

(A )D eletion of in tern a l reg ion

22

(B )

D eletio n of 3 ’ re gio n

7

(C )

D eletio n of fu ll g en o m ic re gio n

2

(D )

T ran sloca tion , in v ersion etc .

7

References
1) K. Ito et al., JAEA Annual Report 2005 (2006) 98.
2) M. E. Mayorga et al., Genetics 126 (1990) 73.

－ 94 －

JAEA-Review 2007-060

3-29 Deletion of Minor Enzyme Activities of Rhizomucor
miehei by Heavy Ion Beam Irradiation
a)

a)

a)

a)

b)

K. Sakai , H. Kobayashi , A. Oshima , S. Kato , K. Satoh and I. Narumi
a)

b)

b)

Tokyo Research Laboratory, Meito Sangyo Co., Ltd., Radiation-Applied Biology
Division, QuBS, JAEA

1. Introduction
Cheese is one of the major dairy product and various kindof cheese are produced in the world. Rennet, which breaks
kappa-casein and induces coagulation of milk, is originatedfrom veal of lactating calf or lamb stomach or produced byfermentation of Rhizomucor (Rh.) miehei. Rh. miehei also
produces various minor enzymes such as lipase and these
enzymes usually cause production of undesirable flavors
during maturation of cheese. For this reason, acidificationand chemical treatments are employed to improve theproperty. However, these treatments also cause loss ofcoagulation activity. Therefore, breeding a strain oflipase-less or very low lipase activity is expected for
improving the productivity and quality of cheese.
The survival rate of sporangiospore was about 1%
following 200 Gy irradiations of 12C5+ at 220 MeV and
20
Ne8+ at 350 MeV. On the other hand, He and Ar ions had
lower effect on survival rate than those of C and Ne ions.
In 2006, lipase-less mutant strain separation was performedby irradiation of C and Ne ions at doses of 100 and 200 Gy
to spore.
2. Materials and Methods
Sporangiospore of two parent mutants of Rh. mihei
obtained by chemical and γ-ray mutagenesis was harvested
from plate cultivation and was spread on a petridish as
previously reported. Spore was dried over silica gel,conditioned over saturated NaCl solution, and covered withpolyimide film for the beam irradiation. The beamirradiation of C-220 MeV and Ne-350 MeV was performedat AVF cyclotron of TIARA.
Irradiated spore was resuspended in sterile water, spreadover glucose-yeast extract agar plate, and cultivated at 37 ˚Cfor three days. A mutation rate was determined by afrequency observation of red-pigmented colony that wascaused by the mutation in AMP-synthesis pathway andaccumulation of polyribosyl-aminoimidazole during
cultivation at 37 ˚C 1).
After mutation rate determination, the colonies weretransfer to agar plate containing milk to detect secreted
rennet activity from colonies. Coagulation activity was
detected by formation of clear zone on the milk agar plate.
After contacting with the milk agar plate overnight, thecolonies were transferred onto agar plate containing olive
oil to detect lipase activity secretion. Colonies thoseformed inarticulate clear zone on each medium were
cultivated to confirm the coagulation and lipase activity
production by a tube cultivation with a medium that wasconsisted of soybean flower and soluble starch. Lipase
activity was determined by an alkali-titration released fatty
acid from olive oil. Coagulation activity was determinedby comparing clotting time (time for initiating coagulationof milk) with a standard enzyme using skimmed milksolution as a substrate.
3. Results and Discussion
Mutation rate varied from 0.06 to 0.99 %.
Amutagenesis effect of neon ions was lower than that ofcarbon ions as shown in Table 1.
After observation of the mutation rate, colonies weretransferred onto milk-agar and then oil-agar medium toselect a deficient mutant by an inarticulate clear zone
formation. All mutants isolated on agar media excreted
lipase in tube cultivation. Among them, some mutants
showed several times smaller activities than that of theparent strain (Table 2).
These mutants might beheterozygous and further purification is necessary.
A mutant strain with low coagulation activity was also
found and its culture product showed a different
chromatographic profile from that of parent (data notshown).
Table 1 Mutation rate by irradiation of heavy ion beams.
Irradiated spore was spread on agar plate medium andcultivated for 3 days at 37˚C. Mutation rate is defined as
the ratio of red-pigmented colonies in total colony.
Parent Irradiation
Total colony Mutation rate
B
C-100 Gy252
0.40%
C-200 Gy
1,313
0.99%
Ne-100 Gy
1,805
0.06%
D
C-200 Gy406
0.49%
Table 2 Mutants with low lipase activity.
Mutant strains were isolated from the parent strain B and D
irradiated with neon and carbon ions at a dose of 200 Gy.
Enzyme activity was shown as a proportional value to theactivity of each parent.
MutantCoagulation
Lipaseactivity
activity
B-14 (Ne-200 Gy)
95%
23%
B-43 (Ne-200 Gy)
102%
21%
D-57 (C-200 Gy)
35%75%
Reference
1) F. J. Jin et al., Biosci. Biotechnol. Biochem. 68 (2004)
656.

－ 95 －

JAEA-Review 2007-060

3-30 Spectral Analysis of DNA Damages60Induced by He2+ Ion
Beam Compared to Those of Co γ-raysa)K. Akamatsu , S. Wadab)and Y. Kobayashi

a)

c)

b)

Division of Environmental and Radiation Sciences,NSED, JAEA, Laboratory of Veterinary
Radiology and Radiation Biology, Kitasato University School of Veterinary Medicine,c)Radiation-Applied Biology Division, QuBS, JAEA

1. Introduction
Information in relation to chemical structures and theirdistribution on DNA is quite important to clarify following
biological repair procedures. In case of ionizing radiations,especially, it is expected that three-dimensional distributionof DNA damages is diversified as well as their chemical
structures, and the diversity makes investigations ofphysicochemical processes in radiation effects difficult. In
fact, double-strand breaks produced by high linear energy
transfer (LET) alpha particles are more difficult to rejoin in
living cells than those produced by low LET 137Cs γ-rays1).
To investigate difference of DNA damage spectrum
between radiations, we have developed new methodology toanalyze strand break-termini and nucleobase lesions using
snake venom phosphodiesterase (SVPD), calf intestinalalkaline phosphatase (CIAP) and piperidine2). In this report,
the results of the DNA damage spectra induced by He2+ ion
beams and 60Co γ-rays are demonstrated. The He2+ ion
beams used was obtained from TC-1 port of 3 MV tandem
accelerator in TIARA at Takasaki Advanced Radiation
Research Institute. The 60Co γ-rays, as a standard radiation
source, were irradiated in the second cell in the first buildingof γ-irradiation facility at the same institute.
2. Materials and Methods
Linear formed pUC19 plasmid DNA digested with SmaI,(pUC19/SmaI) was used. pUC19/SmaI aqueous solution was
mounted on a silicon plate and dried thoroughly in vacuum
under P2O5. For γ-irradiation, the dried DNA sample on aplate was put into a glass tube sealed in vacuum to achieve
secondary electron equilibrium. Each sample was irradiatedat a dose (dose rate) of 40 (0.333), 100 (0.833), 400 (3.33),
900 (7.50), and 1,800 kGy (15.0 kGy/h) at r.t., respectively.
For He2+ beams, the DNA-mounted plate was fixed in acylindrical chamber (39 mmφ, hight: 22 mm) with a
Kapton® window (8 μm) under argon gas. Each sample wasirradiated with ~ 200 keV/μm of the beam just under the
Bragg-maximum, which was controlled using adepth-tunable cell irradiation equipment, at a dose (doserate) of 100 (1.068), 400 (1.068) and 900 kGy (1.068
kGy/pass) at r.t.. The irradiated DNA samples wererecovered by water at 0°C to be 0.32 μg/μL.
The new method for DNA damage analysis is indroduced
in previous paper in detail2). In brief, the solution dissolving
irradiated DNA was treated directly by SVPD, or wastreated by SVPD following to CIAP pretreatment, toproduce 5’-deoxynucleotides (pdNs) from 3’ termini
without phosphate for 15 min at 31.4 °C. The pdNs were
quantified by HPLC after dephosphorylation to be

2’-deoxynucleosides by additional CIAP treatment.
Furthermore, the irradiated DNA sample was pretreated bypiperidine, to convert a variety of nucleobase damages andabasic sites into 3’ termini with phosphate. The increase of
3’termini with phosphate by piperidine treatment reflects theamount of piperidine-labile nucleobase lesions and abasic
sites. Based on the series of the experiments, the yields oftotal 3’termini, those of 3’termini with or without phosphate,and piperidine-labile lesions were calculated. (Table 1).
3. Results and Discussion
Table 1 shows the yields of DNA lesions calculated.
Additionally, the yields of unaltered nucleobase release arealso demonstrated as a reference. In case of the strand break
patterns, the yields of them for He2+ were almost the sameas those for γ-rays. In general, 3’ termini with phosphate
were predominantly produced compared with those without
phosphate. On the other hand, in case of piperidine-labile
lesions, the yields of them for He2+ were twice as large as
those for γ-rays. This tendency was shown also in case of
unaltered nucleobase release. Although the yields ofnucleobase lesions for high-LET radiations would be larger
than those for low-LET radiations according to the datafrom the table, it is also possible that piperidine-labile sites
are susceptible to be produced in the high-LET radiation
field. Anyway, more investigation additionally using
base-excision enzymes should be needed to clarify thedifference between the radiations. Moreover, the differencesin DNA spectrum between on and off peaks of the
Bragg-maximum, and between some degrees of hydration of
DNA molecule are to be investigated.

4. Acknowledgments
We would like to gratefully thank Dr. Y. Hase at Gene
Resource Research Group in Takasaki Advanced ResearchInstitute for maintaining and operating the TC-1 beamline.
References
1) C. M. deLala et al., Radiat. Res. 144 (1995) 43.
2) K. Akamatsu, Anal. Biochem. 362 (2007) 229.

－ 96 －

JAEA-Review 2007-060

3-31 DNA Damage Yields in Hydrated DNA after Carbon
Ion-irradiation
a)

a)

b)

b)

T. Ushigome , H. Tauchi , A. Yokoya , N. Shikazono , K. Fujii

b)and A. Urushibara

a)

b)

b)

Department of Environmental Sciences, Faculty of Science, Ibaraki University, Advanced
Science Research Center, JAEA

Ionizing radiation causes various types of DNA lesions,such as strand breaks, base lesions and, in particular,
biologically relevant complex damage known as cluster
damage sites, which consist of two or more elemental
lesions within one or two helical turns of DNA 1). Clustered
DNA damage sites are considered to be less readily repaired
than isolated lesions and therefore may induce deleterious
and serious genetic changes in cells. The complexity ofclustered damage is proposed to increase on increasing theionizing density of the radiation (LET). It has been
demonstrated that the direct effect of low LET radiation
produces 30-40 % of the lesions in cells2). This value isshown to reach 70 % when cells are irradiated with
α-particles2). However, few investigations have beensystematically undertaken to elucidate the nature of lesions
produced by the direct effects of radiation with varying
ionizing density.
To gain insights on the nature of lesions induced by the
direct effect of the radiation, yields of single- anddouble-strand breaks (ssb’s and dsb’s), and base lesions forhydrated plasmid DNA were measured after exposure tocarbon ion particles with varying LETs. The use of hydrated
DNA eliminates the indirect effect of radiation arising from
irradiation of bulk water. Base lesions were detected asadditional strand breaks after treatment of irradiated DNA
with two glycosylases, Nth and Fpg proteins, which convert
the oxidative base lesions into an ssb.
The yield of prompt ssb after exposing hydrated plasmid
DNA to carbon ion particles with a LET of 87 keV/µm was
6.2 X 10-11 ssb/Gy/Da (Fig. 1). The yields were found to be
fairly similar for carbon ion particles with LETs of 122, 342
and 507 keV/µm. This value of around 6 X 10-11 ssb/Gy/Da
is comparable to that obtained after γ- irradiation 3). Whilethe yield of prompt ssb does not alter with varying LET

values from 87-507 keV/µm, the yield of prompt dsb
appears to increase as the LET increases (Fig. 2).
Consequently, the ratio of prompt ssb to dsb tends todecrease as the LET increases, indicating that strand breaks
in close proximity, which would produce dsb’s, are more
readily induced at higher LET.
Results of enzymatically induced ssb/dsb revealed thatthe amount of base lesions susceptible to cleavage by Nth
and/or Fpg becomes less as the LET gets higher (Fig. 1 andFig. 2). Although we cannot fully disregard the possibility
that the number of damaged bases is actually reduced at
higher LET, we favor the interpretation of base lesions
being clustered and thus becoming less readily cleaved by
the glycosylases. Inhibition of excision of damaged bases
within a cluster has been indeed demonstrated using purified
enzymes4). It should be noted that the yields of prompt andenzymatically induced DNA damage after exposing tocarbon ion particles with a LET of 87 keV/µm were lower
than those of helium ion particles with a LET of 95
keV/µm5). This result suggests that the LET is not fully
sufficient a parameter to describe the nature of damage
clustering and that rather the actual density of ionization
should be taken into account.
In summary, our results indicate that DNA lesions inhydrated plasmids become more readily clustered onincreasing ionizing density of the radiation.
References
1) Goodhead, D. T. Int. J. Radiat. Biol. 65 (1994) 7.
2) de Lara, C. M., et al. Radiat. Res. 144 (1995) 43.
3) Yokoya, A., et al. J. Am. Chem. Soc. 31 (2002) 8859.
4) Weinfeld, M., et al. Radiat. Res. 156 (2001) 584.
5) Urushibara, A., et al. Radiat. Prot. Dosimetry 122 (2006)
163.
X10 -12
20

)a
D
/
y 15
G
/
bs
s(
bs 10
s
f
o
. 5
o
N
0
0

No. of dsb (dsb/Gy/Da)

No. of ssb (ssb/Gy/Da)

X10 -11
20

100

200

300

400

500

)a
D
/y
G15
/b
sd
(
bs 10
d
f
o
.
o 5
N
0

600

0

LET (k eV/μm)

100

200

300

400

500

600

LET (keV/μm)

Fig.1 Number of prompt and enzymatically induced single strand
breaks as a function of LET (keV/µm). Prompt (￭), Mocktreatment of enzymes (●), Fpg treatment (□), Nth treatment(◆),
Fpg+Nth treatment (▲)

Fig.2 Number of prompt and enzymatically induced double strand
breaks as a function of LET (keV/µm). Prompt (￭), Mocktreatment of enzymes (●), Fpg treatment (□), Nthtreatment(◆), Fpg+Nth treatment (▲)－ 97 －

JAEA-Review 2007-060

3-32 Analysis of Cellular Effects and Local Damage Induced
by High LET Heavy Ionsa), b)b)b)

b)

S. Wada, T. Funayama , T. Sakashita , K. Fukamoto , N. Hamada
a) b)
c)
b)
a), b)
T. Hara , , T. Kakizaki , M. Suzuki and Y. Kobayashia), b),a)

Department of Quantum Biology, Division of Bioregulatory Medicine, Gunma Universityb)
Graduate School of Medicine, Radiation-Applied Biology Division, QuBS, JAEA,
c)
Department of Veterinary Medicine, Kitasato University

Introduction
High linear energy transfer (LET) radiation, such as
heavy ion beam, has greater biological effectiveness thanlow LET radiation. Higher biological effectiveness of highLET radiation is probably a consequence of local damage
like clustered DNA damages that contain locally multiple
oxidized bases, single strand breaks and double strand
breaks (DSB), because it is considered that the clustered
DNA damage is non-repairable or more difficult to repair
than a lesion sparsely induced. On the other hand,
mammalian cells efficiently detect and repair DNA damage.
Especially, mammalian cells have evoked two pathway forrepairing DSB, homologous recombination (HR) andnon-homologous end joining (NHEJ). The major pathway inmammalian cells is NHEJ. Many proteins are involved in
NHEJ which include Ku70/80 heterodimer, DNA-PKcs,
XRCC4 and ligase IV. First, Ku bind to the ends of a DSB
and DNA end binding by Ku initiates a cascade ofmolecular events that leads to joining of the broken DNA
ends. In addition to DNA repair, Ku protein plays a role inmultiple nuclear processes, such as chromosome
maintenance and transcription regulation. However, muchless is known about the yield and reparability of clustered
DNA damages.Recently we suggest that the number of
non-repairable DSB by Ku–dependent DSB repair systemincreases with increasing LET. In this study, to investigate
non-repairable DSB by Ku–dependent DSB repair system
we analyzed behavior of Ku protein to DNA damage
induced by high LET heavy ions.
Material and Methods
We transfected pGFP-Ku80 into xrs-5 cells (mutated inKu80). This cell was grown in MEM-alpha medium
supplemented with 10 % serum and were incubated at
37 ℃ in a humidified atmosphere of 5 % carbon dioxide
and 95% air. Accelerated ions of 220 MeV C5+ (108keV/μm), 460 MeV Ar13+ (1610 keV/μm) were provided by
the AVF cyclotron at TIARA JAEA-Takasaki. Cells were
irradiated with ion beams. To evaluate DNA damage and
NHEJ pathway induced by heavy ion beams, we carried out
immunohistochemical detection of phosphorylated histone
H2AX (γ-H2AX). Cells were attached on the CR-39 filmthat is a particle track detector. After post-irradiate
incubation of 10-30 min, the cells were fixed by 1 %paraformalehyde in PBS. Then, the cells were incubatedwith anti-γH2AX antibody for detecting DNA double strand

break sites in situ. Thereafter, the cells were counter-stainedwith DAPI and the opposite side of the CR-39 film wasetched with KOH-ethanol solution at 37 °C. Using a
conforcal microscope, we took images of the cells (γH2AX
and GFP-Ku80) and the etched pits on the CR-39 film at asame field of view. By merging all images together, theposition of hit-ions, γH2AX and GFP-Ku80 were
simultaneously detected. Additionally, because Ku70/80 and
DNA-PKcs formed complex in NHEJ pathway, in situ
localization of DNA-PKcs was also analyzed.
Results and Discussion
In xrs5 -GFP-Ku80 cells, the site of γH2AX foci and thesite of etched pits were coincident. In addition, GFP-Ku80
foci co-localized with those of γH2AX. These observations
show that Ku80 proteins localize to DNA damages inducedby ion beam irradiation, indicating that Ku80 protein canrecognize and bind to DNA damages induced by heavy ion
irradiation. The GFP-Ku80 foci were observed in thesamples of 10 min to 30 min after C ion irradiation, and, atthe same moment, DNA-PKcs also were localized to DNA
damage sites. This observation suggests that the damage
induced by C ion irradiation is repairable by Ku-dependent
DNA repair pathway. On the contrary, the foci of
GFP-Ku80 were observed in 10 min after Ar ion irradiation,
but they disappeared in 20 min or later (Fig.1). In addition,co-localization of GFP-Ku80 and DNA-PKcs was not clear
even in 10 min after Ar ion irradiation. These results
indicate that Ku80 can bind to DNA damage induced byhigh LET heavy ion like Ar, but cannot form a complex
with DNA-PKcs, resulting in failure of NHEJ repair of
induced DNA damages.

Fig.1. Cell with co-localization signal of GFP-Ku80 and
γH2AX after C ion and Ar ion irradiation.

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JAEA-Review 2007-060

3-33 Analysis of Molecular Mechanisms for Radiation-induced
Bystander Effects Using Heavy Ion Microbeams
a)

a)

b)

b)

e)

H. Matsumoto , M. Hatashita , M. Tomita , K. Otsuka , T. Funayama ,e)c,d,e)
c,d,e)
T. Sakashita , N. Hamada
and Y. Kobayashia)bFaculty of Medical Science, University of Fukui, )Central Research Institute of Electricc)d)Power Industry, Gunma University Graduate School of Medicine, The 21st Century
Center of Excellence Program for Biomedical Research Using Accelerator Technology,e)Radiation-Applied Biology Division, QuBS, JAEAThe objective of this project is to elucidate molecular mechanisms of the bystander effect using heavy ion microbeams in
JAEA. We found that the foci of γH2A.X and pNBS1 were formed in the unirradiated cells in the target colony including theirradiated cell 6 h after irradiation with 460 MeV 40Ar beams and that this formation of the foci was almost completely
suppressed by the addition of DMSO or Lindane. Also we found that the foci of γH2A.X and pNBS1 were formed in theunirradiated cells in the untargeted colonies 6 h after irradiation and that this formation of the foci was almost completely
suppressed by the addition of aminoguanidine or c-PTIO. Our findings strongly suggested that ROS and NO are
initiators/mediators for evoking heavy ion microbeam-induced bystander effects.
低線量／低線量率放射線に対して生物が示す特異的な応答様式の一つに放射線誘発バイスタンダー効果がある1) 。我 々 は 、日 本 原 子 力 研 究 開 発 機 構 に お い て
開 発 さ れ た 重イオンマイクロビーム細胞照射システ
ム（細胞局部照射装置）を用いて、この放 射 線 誘 発 バ
イスタンダー効果の分子メカニズムを明らかにすることを計画した。
1. 実験方法(1)細 胞 ： ヒ ト 正 常 線 維 芽 細 胞 (AG1522 細 胞 )を 用いた。
(2)培 養 ： 開 孔（ 径 12 mm）35 mmデ ィ ッ シ ュ の 内
面 中 央 に 20 mm四 方 の CR-39 を パ ラ フ ィ ン で 固
定 し た も の を 使 用 し た 。 ま た CR-39 の 表 面 を
collagen コ ー ト し て 細 胞 を 培 養 し た 。 2×10 5
cells/mlの 細 胞 懸 濁 液 5 µlを CR-39 樹 脂 上 に 5 箇
所 ス ポ ッ ト し (1000 cells/colony)、 15~20 時 間 培
養したものを照射実験に供した。
(3)照 射：Funayamaら 2) の 方 法 に 従 っ て 、中 央 に ス
ポ ッ ト し た コ ロ ニ ー の 細 胞 1 個 に 5 粒 子 の 460
MeV 40Ar13+を HZ1 ポ ー ト に お い て 照 射 し た 。また 対 照 実 験 と し て 460 MeV 40Ar13+をHY1 ポ ー トにおいても照射した。
(4)細 胞 の 蛍 光 免 疫 染 色 ： 照 射 後 、 細 胞 を 37°Cで培 養 し 、 0.5 お よ び 6 時 間 後 に メ タ ノ ー ル で 固
定 し 、 リ ン 酸 化 型 H2AX（ γH2AX） 抗 体 お よ び
リ ン 酸 化 型 NBS1（ pNBS1） 抗 体 を 用 い た 蛍 光
抗 体 染 色 法 に よ り 染 色 し 、蛍 光 顕 微 鏡 下 で 観 察
し た 3) 。標 的 細 胞 を 含 む 正 方 形 枠（ 250 x 250 µm;
C） 内 、 そ こ か ら 右 方 向 に 設 定 し た 2 個 の 正 方
形 枠 （ 250 x 250 µm; Aお よ び B） の 内 部 、 お よび遠隔に存在するサテライトコロニーの中心部 の 正 方 形 枠 （ 250 x 250 µm; S） 内 の フ ォ ー カス形成頻度を測定した。
2. 結果および考察(1)標的細胞での γH2AX お よ び pNBS1 の フ ォ ー カ ス
形 成：Ar 線マイクロビームの照射により、照射された細胞において γH2AX お よ び pNBS1 のフォーカ

ス形成が認められ、それらは同所局在していた。
(2) バ イ ス タ ン ダ ー 細 胞 に お け る γH2AX お よ び
pNBS1 の フ ォ ー カ ス 形 成 ： Ar 線マイクロビーム
照射により、バイスタンダー細胞においても γH2AX
お よ び pNBS1 のフォーカス形成が認められ、それらは同所局在していた。従って標的細胞から分泌された可溶性低分子物質（バイスタンダー因子）によりバイスタンダー細胞に DNA 二本鎖切断が誘発されていることが示唆された。またバイスタンダー細胞におけるこれらのフォーカス形成は標的細胞から離れるに従ってその頻度は減少した。
(3) バイスタンダー因子の種類に依存したバイスタンダ
ー効果の発現：Ar 線マイクロビーム照射により、バイスタンダー細胞における γH2AX お よ び pNBS1のフォーカス形成が Dimethylsulfoxide（DMSO, 0.1%）、
Lindane（40 µM）、Aminoguanidine（AG, 10µM） お
よび carboxy-PTIO（c-PTIO, 10 µM）によって抑制された。DMSO は ROS の消去剤、Lindane は細胞間のギャップ結合の阻害剤、AG は nitric oxide (NO)ラジカル合成酵素の阻害剤、c-PTIO は NO ラジカルの消去剤である。DMSO による抑制は、C および A において顕著であり、それ以外の部位では抑制効果は認められなかった。Lindane による抑制効果は C においてのみ顕著であった。AG および c-PTIO による抑制効果は、A、B および S において認められたが、特に S において最も顕著であった。
以上の結果よりギャップ結合を移行しているバイス
タンダー因子および標的細胞近隣の細胞に培地を介して作用しているバイスタンダー因子は活性酸素種（ROS）であることが示唆された。一方、遠隔的に作用しているバイスタンダー因子は活性窒素種（RNS）、
特に NO ラジカルであることが示唆された。
References
1) H. Matsumoto, et al., J. Radiat. Res., 48, 97 (2007)
2) T. Funayama, et al., Radiat. Res. 163, 241 (2005).
3) A. Takahashi, et al., Cancer Res. 64, 8839 (2004).

－ 99 －

JAEA-Review 2007-060

3-34 Exposure of Normal Human Diploid Fibroblasts to
Heavy Ions Facilitates Differentiation in Their Progeny
N. Hamadaa,b), T. Hara

a,b)

b)

, T. Funayama , T. Sakashitab)and Y. Kobayashi

a,b)

a)

Department of Quantum Biology, and The 21st Century COE Program, Gunma Universityb)
Graduate School of Medicine, Radiation-Applied Biology Division, QuBS, JAEA

Radiation-induced genomic instability encompasses a variety of delayed effects that occur in the progeny of survivors
multiple generations after the initial insult. LET dependence of these effects is incompletely characterized; however, we havepreviously found that delayed reductions in clonogenicity can be most pronounced at LET of 108 keV/µm. To gain insight
into potential cellular mechanisms underpinning LET-dependent delayed loss of clonogenicity, we investigatedmorphological changes in colonies arising from normal human diploid fibroblasts exposed to 60Co γ-rays (0.2 keV/µm) or
carbon ions (18.3 MeV/amu, 108 keV/µm). Carbon ions were fourfold more effective at inactivating cellular clonogenic
potential and produced more abortive colonies containing reduced number of cells per colony than γ-rays. Second, colonies
were assessed for clonal morphotypic heterogeneity. The yield of differentiated cells was elevated in a dose- and LETdependent fashion in clonogenic colonies, while differentiated cells dominated to a comparable extent irrespective of
irradiation in abortive colonies. The incidence of giant or multinucleated cells was also increased but much less frequent thanthat of differentiated cells. All together, our results indicate that carbon ions facilitate differentiation more effectively than γrays. Accelerated differentiation may account for dose- and LET-dependent delayed loss of clonogenicity in normal human
diploid cells, and could be a defensive mechanism that averts further expansion of aberrant cells.
重粒子は、線エネルギー付与(LET)の低い光子に比べ、生物学的効果比(RBE)が高く、線量分布の集中性にも優れていることから、がん治療に利用されている。
しかし、がん病巣の内部や周囲には正常細胞が混在しているため、放射線治療の際に正常細胞への照射は避けられない。このことから、重粒子がヒト正常細胞に及ぼす生物効果を詳細に解析する必要がある。長い間、放射線の生物効果は、核が照射された細胞にのみ認められると考えられてきたが、近年では、細胞質が照射された細胞、さらには、照射子孫細胞(遺伝的不安定性)や照射周囲の細胞(バイスタンダー効果)にまで及ぶ
ことが明らかになってきた 1) 。放射線照射子孫細胞には、照射後の分裂を経た後に、増殖死や染色体異常などが遅延的に誘発されることが知られている。我々は、これまでに、放射線誘発遅延的増殖死のLET依存性に関して、2次コロニー形成能(1個の照射細胞に由来して形成される1次コロニーを回収・再播種させた場合の細胞のコロニー形成能)の喪失を指標としたRBEが
108 keV/μmで最大になることを報告してきた2)。本研
究では、1次コロニーを構成する細胞の形態変化を解析することにより、照射子孫細胞に遅延的に誘発される応答と、LET依存的な2次コロニー形成能喪失の機序を細胞レベルで明らかにすることを目的とした。
細胞周期による感受性のばらつきを軽減させるため、
そして、細胞間相互作用はストレス応答に重要な役割を果たしている 3) ことから、ヒト正常二倍体線維芽細胞AG01522を1x104 cells/cm2の密度で播種後、4・7・9
日目に培地交換し、11日目に放射線照射実験に使用した。60Co γ線(0.2 keV/μm)、または、TIARAにて炭素線(18.3 MeV/amu、108 keV/μm)を照射後1時間以内に再播種し、13日間培養し、形成されたコロニーを固定・染色した。顕微鏡下で、コロニーあたりの細胞数を計数するとともに、細胞の形態を観察した。生存率は50細胞以上のコロニー数から算出した。

γ線の10% 生存線量に対する炭素線のRBEは3.9であった。線量とLETに依存して、コロニーあたりの細胞数は減少し、特に2-7細胞のコロニーの割合が著しく増加した。形態変化を起こした細胞の割合は、50細胞以上のコロニーでは線量とLETに依存して増加したが、50細胞未満のコロニーでは照射の有無に依らずほぼ一定であった。コロニー内には巨細胞や多核化細胞も認められたが、観察された形態変化の大半を占めたのは、分化が進行した細胞であった。分化した細胞、巨細胞、多核化細胞のいずれもコロニー形成能を喪失していると考えられるため、照射子孫細胞への形態変化の誘導は、2次コロニー形成能喪失の機序である可能性とともに、異常を蓄積した細胞の増殖を抑制するための防御機構である可能性が示唆された 4) 。また、分化した細胞の誘発頻度が線量依存的に増加したことから、DNA損傷が一因となり分化の誘導を促進することが考えられる。放射線照射後に観察されるクロマチ
ンの構造変化 5) などに由来して形成されるゲノム上の潜在的不安定領域が恒常的な酸化ストレスにより再活性化され、照射子孫細胞に遅延的にDNA損傷が誘発されると考えられている。このことから、照射細胞に誘発されるDNA損傷が起因となって子孫細胞に遅延的に誘発されるDNA損傷が、チェックポイントを活性化することにより遺伝的不安定性の形質が永続的に発現すると考えられる。今後は、重粒子線誘発遺伝的不安定性の分子機序を明らかにしていきたい。
References
1) N. Hamada et al., J. Radiat. Res. 48 (2007) 87.
2) N. Hamada et al., Radiat. Res. 166 (2006) 24.
3) N. Hamada et al., Carcinogenesis 24 (2003) 1723.
4) N. Hamada et al., Mutat. Res. (2007) in press.
5) N. Hamada et al., Radiat. Res. 166 (2006) 31.

－ 100 －

JAEA-Review 2007-060

3-35 Radiation Induced Apoptosis in Drosophila Cells
a)

b)

a)

b)

b)

b)

H. Kawamura , K. Tatei , T. Nonaka , H. Obinata , T. Hattori , A. Ogawa ,a)c, d)H. Kazama , N. Hamada, T. Funayama d), T. Sakashita d) Y. Kobayashi c, d),)b)T. Nakano a and T. Izumi
a)

b)

c)

Department of Radiation Oncology, Department of Molecular Biochemistry, Department ofd)Quantom Biology, Gunma University Graduate School of Medicine, Radiation-Applied Biology
Division, QuBS, JAEA
8000
7000

Caspase 3/7 activity (RLU)

6000
5000
4000
3000
2000
1000

A
RN
no

EG
ds

as
e
ds

aS

M

M

FP

3

1
as
e

e
aS
ds

nS

M

as

S1
ds

DE
ds

Ar
k

0
ds

Extracellular stresses including radiation were reported toincrease intracellular ceramide concentration in mammaliancells. Cell-permeable ceramide, such as C2 ceramide which
has shortened fatty-acyl chain, was able to induce apoptosis
in many cell lines. These results suggested that ceramide
acts as a signaling molecule in radiation-induced apoptosisof mammalian cells. Ceramide is generated either by denovo synthesis or sphingomyelin degradation catalyzed bysphingomyelinases. The sphingomyelin degradation
pathway was reported that the major source for generating
ceramide in radiation-induced apoptosis. There are threeclasses of sphingomyelinase based on their optimal pH, acid,neutral. Both acid sphingomyelinase (aSMase) and neutral
sphingomyelinase were reported to be activated during
apoptosis. The mechanisms that control radiation-induced
activation of SMases are not well defined. It has been shownthat key components in apoptotic pathway are wellconserved between Drosophila and mammals.
We examined whether ceramide level is regulated during
radiation-induced apoptosis in Drosophila Schneider line 2cell (SL2). Three-fold increase in ceramide was observed 5hours after UV-C irradiation. Addition of cell permeable
ceramide, C2 ceramide, to SL2 cells increased Caspase 3/7
activity. Furthermore, overexpression of ceramidase thathydrolyzes ceramide caused reduction of Caspase 3/7
activity.
We carried out RNA interference experiment to clarify
the ceramide-generating enzyme(s) during the apoptosis.
Caspase 3/7 activity was decreased only by adding the ds
RNA for neutral sphingomyelinase homolog. Other ds
RNAs including acid sphingomyelinase homolog, andsphingolipid Δ4-desaturase had no significant effect. (Fig1)
These results suggested that ceramide have an importantrole in radiation-induced apoptosis and neutral
sphingomyelinase homolog might affect the regulation ofceramide synthesis.

Fig 1. Effects of various dsRNAs for sphingomyeline-related
genes on the hea
Double strand (ds) RNA was added to SL2 and incubatedfor 3 days to allow for turnover of the protein. To induce
apoptosis cells were irradiated with heavy ion.
DEVD-luciferin and luciferase was added to the cell lysate
after 55 hours of irradiation, followed by measurement of
Caspase 3/7 activity
with luminometer. Filled bar:irradiated with 40 Gy of C5+ ion, Gray bar: no irradiation,
Ark: Apaf-1 related killer, DES: sphingolipid Δ4-desaturase,
aSMase1: acid sphingomyelinase homolog-1, aSMase3:
acid sphingomyelinase homolog-3, EGFP: enhanced green
fluorescent protein－ 101 －

JAEA-Review 2007-060

3-36 Pathological and Immunohistochemical Findings of a
Human Glioblastoma Cell Line (CGNH-89) after X-ray
and Heavy-ion Beam Exposure
T. Oishi
a)

a,e)

a)

b,e,f)e,f)b,e,f)c)d), A. Sasaki , N. Hamada, T. Funayama , Y. Kobayashi
a,e)
d,e)
Y. Nakazato and T. Nakanob), S. Ishiuchi

c,e)

,

Departments of Human Pathology, Quantum Biology, Neurosurgery, Radiation Oncology,e)and 21st Century COE program, Gunma University Graduate School of Medicine,f)Radiation-Applied Biology Division, QuBS, JAEA

PurposeIt has not been elucidated whether heavy-ion beamirradiation modulates the biology of glioblastoma at thecellular level. Our project is designed to investigate whether
heavy-ion beam exposure is effective against glioblastoma
cells. We examined a human glioblastoma cell line
(CGNH891)) by morphological and immunohistochemical
techniques after X-ray or heavy-ion beam exposure.
MethodFor X-ray and heavy-ion beam exposure, CGNH89 cells
were divided into 3 groups; control, 5 Gy and 10 Gy
exposure. For each group, cells were fixed at the sametime-points.
Hematoxylin-Eosin(HE)
andimmunohistochemical staining were done in formalin-fixed
cells. For electron microscopy, cells were fixed in fixative(1 % glutaraldehyde, 10% formaldehyde). These samples
were postfixed with osmium and embedded in Quetol 812.
Ultrathin sections were examined under a transmission
electron microscope.
Results and Discussion
After the exposure, both living cells and mitotic cells
decreased in cell number. In the HE staining, nuclear
condensation and apoptotic bodies increased after exposure.
MIB-1 labeling index decreased in the early stage after
exposure, but increased in later stages. It is suggested thatcell cycle arrest and induction of apoptosis was induced by
X-ray and heavy ion-beam exposure in CGNH89 cells.
Ultrastructurally, the nuclei and cytoplasm after exposure
showed a tendency to increase in size. Cellular swellingseems to depend on the swelling of mitochondria, increaseof cellular organelles, cytoskeleton, and secondary lysosome(Fig.1,2). However we did not find out either apoptotic bodyor necrotic change. We conclude that X-ray and heavy
ion-beam exposure might trigger the same morphologicalchanges in the surviving CGNH-89 cells.

Fig. 1 Electron micrograph of the cell after exposure
showing enlarged cytoplasm with vacuolar change.

Fig. 2 Ultrastructurally, the cell exhibits the swelling of
mitochondria and the increase of secondary lysosome.
Reference1)－ 102 －

Ishiuchi S et al, Nature medicine 8 (2002) 971.

JAEA-Review 2007-060

3-37 Bystander Killing of Human Lung Cancer Cells by
Heavy Charged Particle Irradiation
a)

a)

b,c)

c)

a)

c)

K. Harada , T. Nonaka , N. Hamada , T. Funayama , H. Sakurai , T. Sakashita ,
b,c)
c)
a,d)
b,c)
a)
and T. Nakano
S. Wada , T. Kakizaki , M. Hasegawa , Y. Kobayashia)b)

Department of Radiation Oncology, Department of Quantum Biology, Gunma Universityc)d)Graduate School of Medicine, Radiation-Applied Biology Division, QuBS, JAEA, Departmentof Radiation Oncology, Nara Medical University School of Medicine
We have here examined clonogenic survival of confluent human lung cancer A549 cells exposed to X-rays or 220 MeV
C5+ charged particles. Targeted exposure of 0.001-0.005 % of cells within the confluent population were resulted in 7-14 %reduction of surviving fraction. However, this reduction was diminished when cells were treated with the inhibitor of gap
junction. These results suggest that gap junctional intercellular communication plays an essential role in heavy charged
particle irradiation-induced bystander effects.
12

ディッシュ内の細胞を選択的に照射したときの細胞生残率は非照射の細胞と同様であった（データの提示なし）。コンフルエントに培養した細胞でギャップ結合を促進(＋cAMP)するとバイスタンダー効果が促進される傾向にあった(p=0.07)が、ギャップ結合を阻害(＋
lindane)するとバイスタンダー効果が有意に抑制された(P<0.05、Fig.1）。
本 実 験 で は デ ィ ッ シ ュ 全 体 の 細 胞 の う ち 0.0010.005 %という極少数の細胞を重イオンビームで照射した時、ディッシュ全体の細胞生存率が有意に低下する結果が得られたが、細胞間のコンタクトをなくした状態で照射するとこの現象は認められなかった。また
ギャップ結合阻害剤を細胞に接触させることにより照
射後の細胞生残率低下は抑制された。これらより重イ
オン照射による細胞死に照射細胞から非照射細胞へのバイスタンダー効果が関わっており、また、そのシグナル伝達経路にギャップ結合が深く関与していることが示唆された。
1.1

Relative surviving fraction

1． はじめに
これまでのわれわれの検討から、ブロードビームを用いた実験で12C5+の細胞生残曲線は直線的であったが、X線および12C5+のD0（37%生存線量）／D10（10 %生存線量）はそれぞれ1.59 Gy／4.00 Gy、1.23 Gy／2.39 Gyであった。この重イオンビーム照射による細胞死の機序にバイスタンダー効果が関与していることが知られているが、本研究では細胞間のギャップ結合に注目し、重イオンビーム照射後の細胞生残率について検討を行った。
2． 実験方法
細胞はヒト肺癌由来の細胞株A549を用いた（p53statusは野生型）。重イオン照射は原子力機構TIARAの マ イ ク ロ ビ ー ム に て 行 っ た （ 220 MeV 12C 、 108
keV/µm）。照射後の細胞生存率はコロニー形成法で検討した。細胞を高密度（コンフルエント）と低密度に培養した状態で照射するため、照射2日前に底面に固体飛跡検出材（CR-39）を貼付した35mmのグラスベー
スディッシュ上に細胞を準備した（高密度群では5x105個、低密度群では5x10４ 個）。標的細胞はディッシュ中の1-25個の細胞をランダムに選択し、照射するイオンの数はひとつの細胞あたり1-10個とした。照射後は60 mmのディッシュに至適個数の細胞をtriplicate
でまきなおし、14日後に細胞を固定・染色した後、コロニー数をカウントし、非照射細胞の生存率を対照とし細胞生存率を検討した。また、高密度に培養した細胞ではギャップ結合の促進剤（8-Br-cAMP：シグマ社
製：照射の48時間前に添加し1mMに調節）、および阻害剤（Lindane：シグマ社製：照射の2時間前に添加し0.1mMに調節）を加えて照射し細胞生残率を求め、ギャップ結合の関与について検討した。
3．結果および考察
コンフルエントな状態の細胞のうち選択的に1つの細胞にのみイオンを照射した際の細胞生存率は非照射細胞とほぼ同様であった。照射細胞数をディッシュ内の5-25個、また各細胞への照射イオン数を5-10個とすると照射していない細胞の生存率に比較し7-14 %低下
した（P<0.05：データの提示なし）。一方、低密度に細胞を培養し、細胞間のコンタクトをなくした状態でP<0.05

1

0.9

0.8

0.7

Non
irradiation Irradiation+cAMP+LindaneFig.1 Relative surviving fraction of confluent densityinhibited culture of A549 cells where 25cells were
irradiated with 5 carbon ions with or without treatment withlindane or cAMP. The surviving fraction of thenonirradiated A549 control was normalized as 1. The
plating efficiency of control was 46-57 %.

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JAEA-Review 2007-060

3-38 Effects of Heavy-ion Irradiation on the Expression of
Cellular and Viral Genes
a)

a)

a, b)

a, b)

b c)

N. Shimizu , A. Oue , T. Ohtsuki, T. Mori, S. Wada ,
b)
c)
b, c)
a, b)
and H. Hoshino
N. Hamada , T. Funayama , Y. Kobayashia)b)

Department of Virology and Preventive Medicine, and 21st Century COE Program, Gunmac)
University Graduate School of Medicine, Radiation-Applied Biology Division, QuBS, JAEA
Introduction
Heavy-ion irradiation, a new tool for cancer therapy andradiation biology, is expected to cause different responses
on human cells from those by X-rays. The expression ofsome cellular genes is possibly induced by heavy-ion
radiation. The aim of this study is to identify such genes
using the susceptibility of human cells to humanimmunodeficiency virus type-1 (HIV-1) as an indicator. We
have found that the susceptibility of human cells to HIV-1 isenhanced by heavy-ion irradiation. This enhancement was
not detected in cells irradiated with X-rays. The mRNA
expression of various cellular factors that are involved in
HIV-1 replication, DNA damage or DNA repair were
examined. Effects of various drugs on the mRNA
expression of cellular factors were determined.
1. Materials and Methods
Human glioma cells transduced with CD4 and CCR5 genes,
NP-2/CD4/CCR5 1), and NP-2/CD4/CCR5 cells transducedwith green fluorescence protein (GFP) gene driven by
HIV-1 LTR, NP-2/CD4/CCR5/LTR-GFP, were used in thisstudy. NP-2/CD4/CCR5 cells were irradiated with carbon(C) ion or X-ray at different doses (0.5, 1.0, 2.0, and 4.0 Gy).
Then, NP-2/CD4/CCR5 cells were exposed to a
CCR5-using (i.e. R5-tropic) HIV-1 strain, Ba-L, 48 hour
after irradiation. The susceptibility of NP-2/CD4/CCR5
cells to HIV-1 was determined by PCR to detect
reverse-transcribed env DNA 24 and 48 hour after infection.
Irradiated NP-2/CD4/CCR5 cells were exposed to HIV-1 at
4 ℃ for one hour and HIV-1 bound on the cells was
detected by RT-PCR. The mRNA expression of various
cellular factors was detected by RT-PCR using total RNA
isolated from NP-2/CD4/CCR5 cells 48 hour after
irradiation. Induction of GFP expression was detected in
NP-2/CD4/CCR5/LTR-GFP cells treated with drugs.
2. Results and discussion
An amount of the reverse-transcribed env DNA was
increased in NP-2/CD4/CCR5 cells infected with HIV-1
after heavy-ion irradiation at 0.5 and 1.0 Gy, suggesting thatthe susceptibility of the cells were enhanced by the radiation(Fig. 1). However, enhancement of the HIV-1 susceptibility
could not be detected in NP-2/CD4/CCR5 cells irradiatedwith heavy-ion at 2.0 and 4.0 Gy. An amount of HIV-1
bound on NP-2/CD4/CCR5 cells irradiated with heavy-ion
at different doses was similar, suggesting that the radiation
has little effect on the efficiency of HIV-1 binding on thecell surface. The enhancing effects of heavy-ion irradiationon the susceptibility of NP-2/CD4/CCR5 cells to HIV-1
may be caused by increased incorporation or genomic
reverse-transcription of HIV-1.
Expression of CD133 (Prominin-1) and NF-kB mRNA wasdetected to be increased in NP-2/CD4/CCR5 cells irradiatedwith heavyion. Expression of histon deacetylase, Ku80, andpoly-ADP ribose polymerase mRNA was decreased in
NP-2/CD4/CCR5 cells irradiated with heavyion. However, arelationship between the enhancing effect of heavy-ion
irradiation on the susceptibility of NP-2/CD4/CCR5 cells to
HIV-1 and the altered expression levels of these cellularfactors has not been elucidated well.
Not only inducers of apoptosis, G2/M arrest of cell cycle,
and acidic stress, but also inhibitors of HDAC andN-glycosylation failed to enhance the susceptibility of
NP-2/CD4/CCR5/LTR-GFP cells to HIV-1. Therefore, noneof these effects induced possibly by heavy-ion irradiation inhuman cells may be involved in the enhancement of HIV-1
susceptibility of NP-2/CD4/CCR5/LTR-GFP cells.
The susceptibility of NP-2/CD4/CCR5 cells to HIV-1 wasupregulated when the cells were pretreated with
5-azacytidine, neuraminidase or Wortmannin, suggestingthat chromosomal demethylation, inhibition of PI3-kinase,or modification of glycosylation of cell membrane factors
may have a role in the enhancing effects of heavy-ion
irradiation on the susceptibility of NP-2/CD4/CCR5 cells to
HIV-1.
Effects of heavy-ion irradiation on expression andactivities of other cellular factors should be analyzed toelucidate its biological effects on human cells.
AB(a) 24 hr after infection
C irradiation (Gy)0

1

2

C irradiation (Gy)

4

HIV-1
GAPDH
GAPDH
GAPDH
RT(-)

(b) 48 hr

after infection
C irradiation (Gy)

HIV-1
GAPDH

Fig. 1. The susceptibilities of NP-2/CD4/CCR5 cells to
HIV-1 after heavy-ion irradiation. (A) Effects of heavy-ion
irradiation on binding of HIV-1 to cells. NP-2/CD4/CCR5
cells were irradiated with heavyion at different doses andexposed to HIV-1 Ba-L strain for one hour at 4℃. HIV-1
bound on the cells was detected by RT-PCR. Expression of
GAPDH mRNA was detected by RT-PCR as controls. (B)Reverse-transcription
of
HIV-1
in
irradiatedNP-2/CD4/CCR5 cells. Reverse-transcribed HIV-1 DNA
was detected by PCR after 24 and 48 hour after viral
exposure.
Reference
1) Y. Soda et al., Biochem. Biophys. Res. Comm. 258(1999) 313.

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JAEA-Review 2007-060

3-39 Morphological Study on the Effects of Heavy Ion
Irradiations to the Isolated Muscle Fibers of SJL Mice
a,b)

a,b)

c)

a)

a)

H. Yorifuji , M. Hino , S. Wada , Y. Tajika , Y. Morimura , N. Hamadac)c)c)b,c,d)
T. Funayama , T. Sakashita , T. Kakizaki and Y. Kobayashia)b,c,d),b)

Department of Neuromuscular and Developmental Anatomy, and The 21st COE
c)Program, Gunma University Graduate School of Medicine, Radiation-Applied Biologyd)Division, QuBS, JAEA, Department of Quantum Biology, Gunma University Graduate
School of Medicine
Muscular dystrophy is a hereditary disease characterized
by progressive muscle wasting and degeneration.
Although many genes affected by the disease have been
elucidated, there remains a wide gap between the mutationsof the genes and the development of the disease. We aretrying to use irradiations of heavy ion beams to skeletal
muscle cells to understand the pathophysiology of thedisease.
In a major subgroup of muscular dystrophy, products of
the affected genes are localized in or around the plasma
membrane. Their absence is supposed to cause the fragilityof the membrane, which leads to the degeneration of themuscle fibers. In a previous study1,2), we found that theirradiation of heavy ion microbeams on isolated single
fibers of the skeletal muscle caused the damage of thesarcolemma, which induced irregular protrusions andinvaginations of the plasma membrane, in addition to thechanges of the cytoplasmic structures such as
disarrangement of the myofilaments, enlargement of thecisternae of sarcoplasmic reticula containing flocculent
matter and increase of autophagy.
Here, we report the results of heavy ion irradiation to theisolated single fibers of SJL mice, which have a mutation in
dysferlin gene and are the model animal of limb-girdle
muscular dystrophy type 2B and Miyoshi muscular
dystrophy.

Single fibers of SJL mice were isolated by collagenase
treatment and plated on CR-39 plastic cover slips.
Specimens were irradiated with either microbeam (40Ar:
11.2 MeV/amu or 20Ne: 12.8 MeV/amu) or broadbeam(40Ar: 460 MeV or 20Ne: 260 MeV, total 1-10 Gy). After
irradiation, the muscle fibers were fixed at various time
points and processed for electron microscopy.
The irradiated fibers of SJL mice showed the samechange as those found in control ICR mice (Fig. 1), namely
irregular protrusions and invaginations of plasma membrane,
disarrangement of thick filaments, distended cisternae ofendoplasmic reticula containing flocculent matter, andincrease of autophagy. In addition, vesicles of unknown
origin and autophagic vacuoles intermingled withdisarranged thick filaments were observed in some areas
under the sarcolemma (Fig. 2). These vesicles may beconcerned with the disturbed turnover of the membrane
system, as dysferlin, which is absent in SJL mice, is
proposed to be involved in the event.

1μm
Fig. 2 Isolated single fiber of SJL mouse irradiated with
Ne-broadbeam (1 Gy). Undulation of the sarcolemma anddisarranged thick filaments under the plasma membrane
were observed. Vesicles of unknown origin and autophagic
vacuoles intermingled with disarranged thick filaments.
20

１μm
Fig. 1 Isolated single fiber of SJL mouse irradiated with
20
Ne-microbeam. Irregular protrusions and invaginations ofsarcolemma, disarrangement of thick filaments, andenlargement of cisternae of endoplasmic reticula wereobserved. Some autophagic vacuoles were also seen.

References
1) M. Hino et al., Cell Struct. Funct. 32 (2007) 51-56.
2) H. Yorifuji et al., JAEA Takasaki Ann.Rep. 2006
(2007) 106.

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JAEA-Review 2007-060

3-40 Relative Biological Effectiveness of Carbon Beams on
Cell Neurons; Approach Using Growth Cone Collapse Assay
W. S. Al-Jahdari
a)

a,c)

a,c)

b,c,d)d)d), Y. Yoshida , N. Hamada, T. Funayama , T. Sakashita ,b,c,d)and T. Nakano a, c)
Y. Kobayashib)

Departments of Radiation Oncology and Quantum Biology, Gunma University Graduatec)School of Medicine, The 21st Century Center of Excellence Program for Biomedical Researchd)Using Accelerator Technology, Radiation-Applied Biology Division, QuBS, JAEA
The relative biological effectiveness (RBE) on neurons
are believed to be difficult to be evaluated due to thecomplexity for culturing them alone, which has meant that
their radio-sensitivity has not been well investigated. The
growth cone collapse (GCC) assay has been reported as a
useful means of quantifying the effects of various factors on
cultured explants of nervous tissue 1-2). Here, we used the
GCC assay to determine the RBE of carbon beams to X-rayson the cell neurons.
Dorsal root ganglia (DRG) and sympathetic ganglion
chains (SYMP) were isolated from day-16 (mature) andday-8 (immature) chick embryos and cultured for 20 h 3).
Thereafter, neurons were exposed to graded doses of X-rays,or high-LET 12C ions (18.3 MeV/amu, 108 keV/μm).
Morphological changes of the neurons were examined
quantitatively by GCC assay. Apoptosis induction was
examined using TUNEL assay (Fig. 1).
Carbon beams induced GCC and neurite destruction in atime and dose–dependent manner (Fig. 2). Day-8 neurons
were more radiosensitive than day-16 neurons (p=0.01). At
12 h post-irradiation, 20 Gy carbon beams and 30 Gy X-rays
induced about 65% and 25% apoptosis, respectively. The
simple regression analysis revealed that the carbon beams
RBE at day-8 DRG and SYMP using the GCC data were 4.6
and 4.2, respectively. Whilst, at day-16 DRG and SYMP
were 3.4 and 3.3, respectively. However, the RBE at day-8
DRG and SYMP for apoptosis induction was 4.1 and 3.7,
respectively, whereas that at day-16 DRG and SYMP was
4.2 and 3.7 respectively. The carbon beams were
3.3-4.6-fold more effective than X-rays for inducing GCC
and apoptosis on neurons. Our implication is that attention
should be considered when estimating the therapeutic
dosage of carbon beams clinically. GCC assay could be
beneficial in in vitro radiobiological investigations.

Fig. 1 Day-16 for both DRG and SYMP after exposure to 10
Gy. Some apoptotic cells (TUNEL-positive) were indicatedby arrow and has gleaming appearance, and non apoptotic
cells were shown as gloomy spots. Number of ganglia used
n = 16. Scale bar = 60 μm

Fig. 2 Growth cones and neurites’ morphologicalappearance. (0 h) before exposure, 12, 24 and 48 h after
exposure with 10 Gy carbon beams.
References
1) Raper et. al., Neuron; 4 (1990) 21.
2) Saito et al., Neurosci. Lett. 229 (1997) 73.
3) Bottenstein et al., Exp Cell Res 125 (1980) 183.

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JAEA-Review 2007-060

3-41 Cell-killing Effect in Bystander Cells Induced by
Carbon-ion Microbeams
a)

a)

b)

b,c)

a)

b)

M. Suzuki , Y. Furusawa , T. Funayama , N. Hamada , C. Tsuruoka , T. Sakashita ,
b)
b,c)
b)
b)
b,c)
T. Kakizaki , T. Hara , K. Fukamoto , Y. Yokota and Y. Kobayashia)b)Research Center for Charged Particle Therapy, NIRS, Radiation-Applied Biology Division,c)
QuBS, JAEA, Department of Quantum Biology, Gumma University Graduate School of Medicine.
A central paradigm in radiation biology has been that only
cells “hit” by a track of radiation would be affected toinduce radiobiological consequences, and cells “not hit”
should not be. This paradigm is the basis for the current
system for risk estimation of radiobiological effects. Also,
the risk of radiation-induced cancer after high and moderate
doses is relatively well known, based on the data fromdetailed epidemiological studies of the Japanese atomic
bomb survivors in Hiroshima and Nagasaki1). However, it
recently has been challenged by so called non-targeted
effects, such as genomic instability, adaptive response andbystander effect, and such radiation-induced non-targeted
effects may have important implications for risk evaluationof low dose / low dose rate radiations.
This year, we have begun to investigate cellular bystander
responses in normal human fibroblasts induced bycarbon-ion microbeams. Carbon-ion microbeams (12C5+, 220
MeV) were generated with the HZ1 port at TIARA.
Approximately 6 x 105 exponentially growing cells were
inoculated into each of microbeam dish, which wasconstructed with an aluminum ring of 36 mm diameter andattached 7.5 µm-thick polyimide film on the bottom of thering, 2 days before irradiation. One day after plating, half ofthe dishes were treated with a specific inhibitor of
gap-junction mediated cell-cell communication (40 µM ofγ-isomer of hexachloro-cyclohexane). At the irradiation
period, cultures were confluent. Cell cycle distribution of theconfluent cultures were analyzed using a flow cytometory
and around 95% of the cells were G1- or G0-phase.
Irradiation was carried out using a 256 (16 x 16)-cross-stripe
method (Fig.1). Microbeams of 20 µm in diameter were
irradiated in each point with 8 delivered ions.
Figure 2 showed cell-killing effect, which was detectedwith a colony-forming assay as a reproductive cell death, in
microbeam-irradiated dishes (IR) and microbeam-irradiateddishes with a specific inhibitor of gap-junction mediatedcell-cell communication (IR+L). The percent cell survival in
microbeam-irradiated dishes was ranging from 83% to 94%,
while from 97% to 100% in microbeam-irradiated disheswith a specific inhibitor of gap-junction mediated cell-cellcommunication. In our microbeam-irradiation method, we
estimated that the percent of C-ion direct hit cells was
ranging from 0.08% to 0.2% of all cells in the dish. The
results showed a higher cell-killing effect in the
microbeam-irradiated cell population than that with a
specific inhibitor of gap-junction mediated cell-cellcommunication. Our studies provide clear evidence thatmicrobeam-irradiated cells can induce a bystander lethal
response in neighboring cells, which are not directly hit by Cions and gap-junction mediated cell-cell communication
play an important role in the bystander effect.
Reference
1) D.A.Pierce and D.L.Preston, Radiat. Res., 154 (2000)
178.

cells

10/11/2006 MT

1/24/2007 MT
100

80

80

60

60

40

40

20

20

0

0

Cell survival (%)

100

30 mm
36 mm

IR

Fig.1 Microbeam-irradiation procedure of normal humanfibroblasts using a 256 (16 x 16)-cross-stripe method. A
microbeam dish was constructed with an aluminum ring of
36 mm diameter and attached 7.5 µm-thick polyimide filmon the bottom of the ring.

IR+L

IR

IR+L

Fig.2 Representative cell-killing effects in normal humanfibroblasts irradiated with C-ion microbeams treated with
(IR+L) / without (IR) a specific inhibitor of gap-junction
mediated cell-cell communication (40 µM ofγ-isomer ofhexachloro-cyclohexane) of 2 independent beam times.

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JAEA-Review 2007-060

3-42 Ion Beam Irradiation Has Different Influences on
Glutathione Peroxidase of Cultured Human Retinal
Vascular Endothelial Cells Exposed to L-dopa among20
Ne, 12C and 4He
K. Akeoa)a,b), N. Hamada

c,d)

c,d)

c)

c)

, Y. Kobayashi , T. Funayama , T. Sakashita ,a)a)K. Kawada and Y. Akeob)

Akeo Eye Clinic, Department of Ophthalmology, Keio University School of Medicine,
c)d)Radiation-Applied Biology Division, QuBS, JAEA, Department of Quantum Biology, Divisionof Bioregulatory Medicine, Gunma University Graduate School of Medicine
It is well-known that the damage of retinal endothelial (RE)cells is one of causes as pathogenesis in senile maculardegeneration and diabetic retinopathy.
Glutathione
peroxidase (GPX), a selenium-dependent and lipid
peroxide-scavenging enzyme that effectively reduces lipid
peroxides with the concomitant oxidation of glutathione is
distributed in mitochondria 1). Faucher et al. measured theexpression of two bcl-2 family members, bax and bcl-2, in ahuman endothelial like cell-line overexpressing the organichydroperoxide-scavenging enzyme GPX, in the absence of
any apoptotic/oxidant stimulus, and showed thatoverexpressing an antioxidant gene such as GPX in
endothelial cells is able to change the basal mRNA andprotein bax levels without affecting those of p53 and bcl-2.
This phenomenon could be useful to antiatherogenic
therapies which use antioxidants with the aim of protecting
the vascular wall against oxidative stress injury 2). The
irradiation is known to result in a dose-dependent decline in
the activities of GPX in the skin of mice 3). The gamma
ray (60Co) causes ionization uniformly in the whole
irradiated tissue. We found out that high dose of gamma
irradiation prevented programmed cell death regulated by
p53 and bcl-2 genes in the ciliary body dissected from living
body, and was useful for preservation of organ after culture
by the protective influence of inflammatory reaction 4).
Deficiency of L-dopa causes degeneration of the substantia
nigra in the brain and L-dopa is used in the treatment of
Parkinson’s disease. We proved that L-dopa produced NO
and superoxide, and had the cytotoxic effects on the retinal
pigment epithelial cells 5). L-dopa injected into thevitreous of the rats dilated the vena in the ciliary body 6).
We wondered if RE cells could be exposed to oxidative
stress by administrated L-dopa. We already reported thatoxidative stress such as hyperoxia 7) augmented thecytotoxicity of the aortic endothelial cells by L-dopa. We
investigated how L-dopa influenced GPX in mitochondria
and the cytoplasm of the RE cells that prevented fromdamage of phospholipid of cell membrane. We applied theion beams as the induction of the oxidative stress that
influenced GPX against in the RE cells, and measured theexpression GPX with LightCycler system as a real timereverse-transcriptase polymerase chain reaction (RT-PCR).

Established human RE cells in vitro incubated with L-dopa(250 µM) for 2 hrs were exposed to an ionization radiationthat is induced by acceleration of the ionizing atom of 350
MeV 20Ne, 220 MeV 12C, and 50 MeV 4He. We obtained
the RE cells after 0, 4, 8, 24 hr of the irradiation andextracted total cellular RNA and cDNA was synthesized.
We used the Primer3 website to design the primers for
RT-PCR amplification of the cDNA of GPX and 18S RNA.
The reactions were carried out at the following temperature:
95 ℃, for denaturation; 60 ºC, for annealing; and 72 ºC, forextension for 17–27 cycles. After mixing the cDNA,
primer, and SYBR green, the expression of 18S RNA andGPX was measured using the LightCycler system. The
technology of this system is extremely innovative andenables rapid and simultaneous evaluation PCR experiments.
Fluorometric analysis of the formed PCR products was
performed as a real-time measurement either continuously
or at specifically defined time points during each PCR
cycle.
Exposure to L-dopa inhibited the expression of GPX in RE
cells. Ion beam irradiations both of 4He and 12C decreased
more remarkably than 20Ne. The expression of GPX in RE
cells incubated with L-dopa decreased significantly after 8
hrs of exposure to 4He, and after 4 and 24 hrs of exposure to12
C. On the contrary, ion beam irradiation of 20Ne
increased the expression of GPX in RE cells incubated with
L-dopa after 4 hrs of the exposure of the irradiation
significantly. We considered the different accumulation of
the energy irradiated at a point by various ions could beconcerned with the effects on the expression GPX in RE
cells incubated with L-dopa.
References
1) K. Watanabe, Tran.Soc Pathology Jpn 76 (1986) 39.
2) K. Faucher et al., Mol Cell Biochem. 277 (2005) 81.
3) J.G. Chandra et al., Clin Chim Acta 332 (2003) 111.
4) K. Akeo et al., Exp. Animals. 55 (2006) 375.
5) K. Akeo et al., Pigment Cell Res. 13 (2000) 80.
6) S.A. Amaki et al., Pigment Cell Res. 14 (2001)256.
7) K.Akeo et al., Exp. Eye Res. 49 (1989) 335.

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3-43 Analysis of Lethal Effect Induced by Ion Beams in
Canine Spontaneous Tumor Cells
a)

a)

a)

b)

b)

S. Wada , T. Ito , T. Kakizaki , T. Funayama , T. Sakashita , Y. Kobayashia)b)

and N. Itoa)b)Department of Veterinary Medicine, Kitasato University, Radiation-Applied Biology Division,
QuBS, JAEA

Due to the recent understanding of animal diseases andpreventive medication including vaccination andpremedication, companion animals can live much longer
than before. These changes made it possible to reducesevere infectious diseases, and then made diseases ofcompanion animals shifts from infectious diseases to theaging-related metabolic disorders and neoplasm (cancer)
formation. Radiotherapy is considered to be one of the good
choices for the medical treatment against cancer. In human
medicine, new radiotherapy such as high-LET heavy-ion
beam radiotherapy has been introduced, because of its
higher lethal effect than that of low LET radiation such as
X- rays and γ-rays. However, in veterinarian medicine, there
is still limited data on X-ray and γ-ray radiotherapy to dogs
and cats, and needless to say, no study on ion beam
radiotherapy. Therefore, to establish a proper protocol forradiotherapy on the animals, we investigated thefundamental aspects of the radiation effects on cancer cellsof companion animals.
Even in the human medicine, the protocol for heavy ion
radiotherapy still cannot be say well optimized, and theinvestigation for its establishment is still undergone. Of
course, the dose per fraction of heavy ion therapy may
become lower than that of X-ray therapy, because of its
higher lethal effect. However the effects of low doseradiation has only been estimated by extrapolation from thedata obtained by the higher dose radiation and notconsidered a concept of low dose specific biologicalresponses such as adaptive response, radiation induced
bystander effects, and low dose radio-hypersensitivity.
Because the effect of those phenomenons cannot be
estimated by extrapolation from the data obtained by highdose exposure, we also investigated lethal effects induced
by low dose/dose-rate radiation that is considered to beimportant on heavy ion radiotherapy.
Cell lines used for this experiment were melanoma cellfrom spontaneously generated canine tumor. The cells were
irradiated with 20 MeV H+ ions (2.7 keV/μm), 220 MeV
12 5+
C ions (108 keV/μm) or X-rays at a dose rate of 0.8
Gy/min at a room temperature and replated on tissue culture
dishes at a given density to measure the rates of thesurviving cells. About 8 days after the irradiation, coloniesof the cells were stained and counted. The survival rates
against the given doses were plotted and fitted to alinear-quadratic model.
The survival curves of carbon ion irradiation showedalmost linear in logarithmic scale and had no shoulder, but
the curves of proton and X-ray irradiation showed to haveshoulders. The lethal effect was highest by carbon ion
irradiation among three types of radiation. The relative
biological effectiveness (RBE) of proton and carbon ionscalculated from the dose required to give 10 % of survival
rate was 1.32 and 2.82, respectively. These results indicatethat the lethal effect increase a with LET value of ion
beams.
The low dose survival rates measured by proton and X
ray irradiation showed good agreement to the extrapolated
curve from the data of high dose irradiation. On the other
hand, low dose survival rates by carbon ion irradiation wereless than the estimated value from extrapolated curve of thehigh dose irradiation (Fig. 1). This result indicates that thelethal effect by low dose carbon ion irradiation is higher
than estimated effect based on higher dose irradiation data.
Additionally, we observed the treatment with DMSO, a
radical scavenger, after low dose carbon ion irradiation
restored the rate of survival to the value that is extrapolated
from high dose irradiation (Fig. 2). This result indicates
there is some participation of radicals in killing effects of
low-dose carbon irradiation. In conclusion, the applicationof carbon ion radiotherapy to malignant melanoma therapy
on companion animals would lead high therapeutic effects.

Fig. 1 Rate of survival of canine melanoma cell lines after
low dose exposure. Lines of survival curves wereextrapolated from 1-8 Gy irradiation data.

Fig. 2 Comparison of lethal effect by treatment with orwithout DMSO after low dose carbon ion irradiation.
Dashed line was extrapolated from 1-4 Gy irradiation data.

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JAEA-Review 2007-060

3-44 Food-NaCl Associative Learning in Response of
C. elegans to Gamma-ray Irradiation
a)

a)

a)

a)

T. Sakashita , M. Suzuki , K. Fukamoto , T. Funayama ,
a, b)
a, b)
c)
d)
, Y. Kobayashi, D. D. Horikawa and A. Bolige
S. Wadaa)b)

Radiation-Applied Biology Division, QuBS, JAEA, Department of Quantum Biology, and The
c)
21st Century COE Program, Gunma University Graduate School of Medicine, Graduate Schoold)of Science, University of Tokyo, United Graduate School of Agricultural Science, Iwate
University

Learning impairments following ionizing irradiation as
well as DNA damages is an important potential risk forastronauts1). We used Caenorhabditis elegans as a neuronalmodel organism, and previously reported that ionizing
radiation affected food-NaCl associative learning behavior
only at the transition stage of learning conditioning, which
induced additional decreases in chemotaxis to NaCl
immediately after irradiation. In the present study, weinvestigated the effects of gamma-ray irradiation on thetime-course and chemotaxis to benzaldehyde.
We used well-fed adults grown on the plate containing 10
ml of the nematode growth medium agar3) and spread with
the E. coli at 20 ˚C in all experiments. Using the method of
Saeki et al.2) with some modifications, we evaluated thechemotaxis to NaCl. Animals move freely for 15 min on the
6-cm diameter assay plate with a gradient of NaCl
concentration. When animals reach to the test spot orcontrol spot, they were paralyzed by NaN3. The test spot is
the place with highest concentration (100 mM) of NaCl in
the plate. The control spot is 4 cm away from the test spot.
The chemotaxis index (CI) was calculated as the following
equation; CI = { (number of animals within 1.5 cm diameterof the test spot) – (number of animals within 1.5 cm
diameter of the control spot) } / (total number of animals on
the assay plate). For the benzaldehyde assay, we used the
10-cm plates, in which 1 µl of ethanol or 0.5 % vol/vol
benzaldehyde in ethanol was spotted at the control or test
spot, respectively. The test spot was 6 cm away from thecontrol spot, and NaN3 was spotted to the both.
To test the effects of gamma-rays on the time-course,
animals on the NaCl-conditioning plates (food-/NaCl+)
were exposed to gamma-rays from 60Co sources, Japan
Atomic Energy Agency (JAEA). We measured chemotaxis
at the time points of immediately after irradiation, 1, 3, 5 hafter irradiation. NaCl-conditioning was continued during
the post irradiation. As shown in Fig. 1, animals exposed to
gamma-rays showed significant decreases in chemotaxis
immediately after irradiation and complicated responses on
post-irradiation. Animals exposed to the dose of 118 or 332
Gy showed almost the same level in CI 5 h after irradiation,
whereas the CI of animals exposed to the highest dose
increased up to the about 0.4.
Gamma-ray irradiation during the stage of conditioning

for associative learning induced the significant decrease in
CI of C. elegans, and then did show the complicatedresponses. We had the question whether other functions of
the nervous system were also affected by gamma-ray
irradiation. Thus, we examined the chemotaxis tobenzaldehyde of animals with same conditioning andexposure as the previous result (Fig. 1). The CIs forchemotaxis to benzaldehyde were 0.84 ± 0.04 (0 Gy), 0.82
± 0.03 (481 ± 32 Gy) immediately after irradiation, and 0.81
± 0.02 (0 Gy), 0.81 ± 0.03 (481 ± 32 Gy) 5 h after
irradiation. There was no significant difference in CI. Thus,
animals exposed to gamma-rays did show the normal
chemotaxis to benzaldehyde, whereas chemotaxis to NaCl
was affected at the transition stage of associative learning.
These results may suggest the specific effects of gammarays on functions of the nervous system in C. elegans.

Figure 1. Time course of CI in NaCl-conditioned andexposed animals during the post irradiation. The error bars
indicate the standard error of mean (SEM) from 5 or moreexperiments.
References
1) Koike et al., Acta Astronautica 56 (2005) 367.
2) Saeki et al., J. Exp. Biol. 204 (2001) 1757.
3) Brenner, S., Genetics 77 (1974) 71.

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JAEA-Review 2007-060

3-45 Food-NaCl Associative Learning in Response of C.
elegans to High-LET Carbon Ion Beam Irradiation
a)

a)

a)

a)

T. Sakashita , M. Suzuki , T. Kakizaki , T. Funayama ,
a, b)
a, b)
a, b)
, S. Wadaand Y. Kobayashi
N. Hamadaa)b)Radiation-Applied Biology Division, QuBS, JAEA, Department of Quantum Biology, and The
21st Century COE Program, Gunma University Graduate School of Medicine.

Learning impairments following ionizing irradiation is an
important potential risk for astronauts as well as DNA
damages1). Using Caenorhabditis elegans as a neuronalmodel organism, we previously showed that ionizing
radiation affected food-NaCl associative learning behavior
only at the transition stage of learning conditioning, which
induced additional decreases in chemotaxis to NaCl
immediately after irradiation. In the present study, weinvestigated the effects of high-LET carbon ion beamirradiation on the ability of associative learning andchemotaxis to benzaldehyde.
Well-fed adults grown on the plate containing 10 ml of
the nematode growth medium agar2) and spread with the E.
coli at 20 ˚C were used in all experiments. Chemotaxis to
NaCl was measured by the method of Saeki et al. 3) withsome modifications. Animals (C. elegans) move freely for
15 min on the 6 cm diameter assay plate with a gradient of
NaCl concentration. When they reach to the test spot orcontrol spot, they were paralyzed by NaN3. The test spot is
the place with highest concentration (100 mM) of NaCl in
the plate, and the control spot is 4 cm away from the test
spot. The chemotaxis index (CI) was calculated as thefollowing equation; CI = { (number of animals within 1.5
cm diameter of the test spot) – (number of animals within
1.5 cm diameter of the control spot) } / (total number ofanimals on the assay plate). For the benzaldehyde assay, weused the 10 cm plates. 1 µl of ethanol or 0.5 % vol/vol
benzaldehyde in ethanol was spotted at the control and test
spots, respectively. The test spot was 6 cm away from thecontrol spot, and NaN3 was spotted to the both.
To test the effects of carbon ions on the ability of
associative learning, animals on the mock-conditioning
plates (food-/NaCl-) were exposed to 12C (220 MeV, 113.3
keV/µm) delivered from the azimuthally-varying-field
cyclotron installed in the Takasaki Ion Accelerators for
Advanced Radiation Application (TIARA) facility, Japan
Atomic Energy Agency (JAEA). Immediately after
irradiation, animals were transferred to the NaClconditioning plates (food-/NaCl+) and placed for 4 hours to
perform the conditioning for the food-NaCl associative
learning. Subsequently, the chemotaxis assays were carriedout. As shown in Fig. 1, there was no significant differencein CI between exposed and non-exposed animals. Thus, theresult suggests that exposure to carbon ions dose not induce
the decrease of the ability of food NaCl associative learningin C. elegans. This result is in accordance with that ofanimals exposed to 60Co gamma rays.

Fig. 1. Dose response of the ability of associative learning.
The error bars indicate the standard error of mean (SEM)from 4 experiments.
We have been reported that carbon ion irradiation during
the stage of conditioning for associative learning induce thesignificant decrease in CI of C. elegans. The finding raises
the question whether other functions of the nervous system
are also affected by carbon irradiation. Thus, we examinedthe chemotaxis to benzaldehyde of animals with same
conditioning and exposure as the previous report. There wasno significant difference in CI (Fig. 2). Thus, animals
exposed to carbon-ions showed the normal chemotaxis tobenzaldehyde, whereas chemotaxis to NaCl was affected at
the transition stage of associative learning. These results
suggest that the carbon ion irradiation did not affect allfunctions of the nervous system in C. elegans.

Fig. 2. Dose response of chemotaxis to benzaldehyde. The
error bars indicate the standard error of mean (SEM) from 4
experiments.
References
1) Koike et al., Acta Astronautica 56 (2005) 367.
2) Brenner, S., Genetics 77 (1974) 71.
3) Saeki et al., J. Exp. Biol. 204 (2001) 1757.

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JAEA-Review 2007-060

3-46 Effect of Energetic Heavy-ion Irradiation on Gene
Expression in Caenorhabdits elegans
a)

a)

a)

a)

a)

b)

A. Higashitani , C. Mori , T. Kimura , T. Ikenaga , T. Takanami , T. Sakashita ,
b,c)
b,c)
b,c)
and Y. Kobayashi
S. Wada , N. Hamadaa)b)Graduate School of Life Sciences, Tohoku University, Radiation-Applied Biology Division,c)
QuBS, JAEA, Department of Quantum Biology, and The 21st Century Center of Excellence
Program, Gunma University Graduate School of Medicine

Heavy ion irradiation, which is more effective than γ
irradiation in inducing DNA damage and gene mutation, hasbeen used for cancer therapy to kill tumor cells. Masumura
et al.1) reported that carbon particles induce deletions,generally greater than 1,000 base pairs in size, whereas
γ-rays induce base substitutions and deletions of less than
100 base pairs. Other different effects of heavy ion
irradiation are not well understood. We, therefore, study theeffect of heavy ion and γ irradiation on gene expression with
DNA microarray analysis of entire genome in
Caenorhabditis elegans.
As a model organism C. elegans is easy to handle andgenetically well-characterized, and its development and life
cycle are well understood. In addition, the transcriptional
profiles of individual cells or tissues at different
developmental stages have been previously reported2). Here,we compared the transcriptional profiles of nematodes thatwere exposed to either 12C5+ ion broad beam (220 MeV)
delivered from the AVF cyclotron or 60Co γ-rays using thewhole genome C. elegans GeneChip array (Affymetrix,
Santa Clara, CA).
To prepare the RNA for microarray analysis, N2 bristol

A: Upregulated
Response to
ER stress

136

51

246

egl-1, ced-13
60Co

12C5+

B: down regulated

304
60Co

54

334
12C5+

Fig.1 Alterations of gene expression by irradiation of either
heavy ion particles or γ-ray radiations.

wild-type hermaphrodites were synchronously cultured on
Escherichia coli OP-50 NGM plates at 20 ℃. Young adult
hermaphrodites (24 h after the L4 larval stage) were
exposed to 100 Gy of 12C5+ ion beam and γ-rays, and werecollected 4 h later. Total RNA in each 103 worms was
isolated with the TRIzol Reagent (Invitrogen Corporation,
Carlsbad, CA) and was used as a template for generatingprobes using the One-Cycle Target Labeling and Control
Reagents package (Affymetrix, Santa Clara, CA).
Transcriptional alterations between heavy ion irradiatedsamples, 100 Gy γ-irradiated samples and non-irradiatedcontrols were measured. Following heavy ion irradiation,
297 transcripts (approximately 1.3 % of the totaltranscriptome) were upregulated 2 fold or greater (Fig. 1).
388 transcripts were reduced at least 2 fold (Fig. 1). On thecontrary, 187 transcripts were upregulated 2 fold or greaterand 358 transcripts were down regulated at least 2 fold after
γ-ray irradiation (Fig. 1). Interestingly, there were only 51(upregulated) and 54 (down regulated) transcripts that weresimilarly affected by both irradiations (Fig. 1).
We further characterized the transcripts which wereupregulated following treatment according to gene function.
The expression levels of genes related to apoptotic inducer
containing BH3 domain, egl-1 and ced-13, and glutathione
S-transferase genes, cdr-2, cdr-3, gst-5 and gst-6, weresignificantly upregulated by either irradiation. It suggeststhat apoptosis and oxidative stress are similarly induced by
100 Gy of 12C5+ ions and γ-rays.
In contrast to γ-rirradiated worms, certain genes
mediating response to endoplasmic reticulum (ER) stresswere significantly and specifically induced in heavy
ion-irradiated worms. These results suggest that the heavy
ion irradiation may efficiently cause both DNA damage and
ER stress. It has been known that heavy ion particle
irradiation efficiently causes apoptotic cell death3, 4). All
together, ER stress induced by heavy ion particle irradiation
may be a direct trigger of apoptotic induction.
References
1) K-I. Masumura et al., Environ. Mol. Mutagen. 40(2002) 207
2) SJ. McKay et al., Cold Spring Harb. Symp. Quant. Biol.
68 (2003) 159
3) A. Takahashi et al., Int. J. Radiat. Oncol. Biol. Phys. 60(2004) 591.
4) M. Aoki et al., J. Radiat. Res. 41 (2000) 16.

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JAEA-Review 2007-060

3-47 Radiation Tolerance Linked to Anhydrobiosis in
Polypedilum vanderplanki
a)

a)

a)

a)

a,b,d)a)Y. Nakahara , M. Watanabe , T. Kikawada , A. Fujita , D.D. Horikawa, T. Okuda ,
b)
b)
b,c)
b,c)
b,c)
and Y. Kobayashi
T. Sakashita , T. Funayama , N. Hamada , S. Wadaa)Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences,c)
Radiation-Applied Biology Division, QuBS, JAEA, Department of Quantum Biology, Gunmad)
University Graduate School of Medicine, Graduate School of Science, The University of Tokyob)glutation peroxidase, and DNA repair enzymes such as
DNA photolyase and TFIIH, increased during dehydration.
Full-length cDNA cloning awaits further studies.
Damage from radiation shares common traits withdesiccation damage: e.g. oxidative stress and DNA break.
Many anhydrobionts seem to cope with that challenge by
antioxidative defense and DNA repair systems. Prompt
repair of DNA upon rehydration can be achieved byprovision of efficient repair systems during entry into
anhydrobiosis. Therefore, the increased radiation tolerance
in P. vanderplanki presented here is probably due tocross-protective effects caused by anhydrobiosis6).
References
1) Hinton, Proc. Zool. Soc. Lond. 121 (1951) 371.
2) Keilin, Proc. R. Soc. Lond. 150B (1959) 149.
3) Watanabe et al., Int. J. Radiat. Biol. 82 (2006) 587.
4) Watanabe et al., Int. J. Radiat. Biol. 82 (2006) 835.
5) Kikawada et al., Biochem. Biophys. Res. Commun.
348 (2006) 56.
6) Watanabe et al., J. Insect Physiol. 53 (2007) 573.
Desiccation
100% RH

Rehydration

76% RH

5% RH

In water

Water
(%)

80
40

W-low

D-highW-highW-mid

Trehalose(% dw)

0
20
10
0

0

24

48
Time (h)72024Fig. 1 Preparation of larvae with different physiologicalconditions. Intact larvae (W-low) were incubated at 100%
relative humidity (RH) for 24 h (W-mid), and further 76%
RH, and 5% RH, each for a day (D-high). D-high larvae
were rehydrated in distilled water for 1 h (W-high).
Larval survival (%)

The larvae of the sleeping chironomid, Polypedilum
vanderplanki, are able to withstand almost complete
desiccation during which they enter a state of suspended
animation1), this phenomenon is known as anhydrobiosis2).
The anhydrobiotic larva can tolerate various extreme
conditions including high doses of radiation3,4). Since
physiological status is drastically changed during entry into
anhydrobiosis5), it is of great interest to know how thedesiccating larvae gain radiation tolerance.
We first examined effects of high-LET radiation on 4
kinds of larvae (Fig. 1): normal hydrated larva (W-low),intermediates between the anhydrobiotic and normal
hydrated state (W-mid), almost completely dehydrated(anhydrobiotic)
larvae(D-high),andimmediately-rehydrated larvae that are assumed to have asimilar molecular profile to anhydrobiotic larvae (W-high)6).
These samples were exposed to 1 to 4500 Gy of 50 MeV
4
He (LET ∞=16.2 keV/µm) ion beam delivered from theazimuthally- varying-field cyclotron at TIARA. Irradiatedlarvae were supplied with distilled water and diet. Larvaethat moved their pharyngeal plunger were considered to be
survivors.
At doses between 3500 and 4500 Gy, differences inradiation effects became pronounced, depending on thephysiological state of the larvae (Fig. 2). For all doses
studied, survival period after radiation was greatest in
D-high, followed by W-high, W-mid, and finally W-low.
This result indicated that radiation tolerance increased as
anhydrobiosis progresses. We previously thought thattolerance against various stresses in P. vanderplanki larvae
is achieved by a complete desiccation. However, radiation
tolerance was increased even in hydrated larvae as well,suggesting the protection mechanisms different from what
we have speculated in desiccated state.
It is possible that trehalose itself has radioprotective
effects in hydrated larvae of P. vanderplanki3). However,high-LET radiation mainly causes harmful damage to DNA
by direct action, which is not reduced by protective agents.
Therefore, it could not be determined whether trehalose
inhibits a direct action of high-LET radiation in P.
vanderplanki. Alternatively, we assume that DNA repair
capacity is increased in desiccating larvae4). We reexamined
the EST (expresses sequence tag) database from desiccating
P. vanderplanki5) and found that fragments annotated as
antioxidation enzymes such as thioredoxin reductase and100

3500 Gy

100

4000 Gy

100

80

80

80

60

60

60

40

40

40

20

20

20

0

0

0

0 2 4 68 10

0 2 4 6 8 10
Days after irradiation

4500 Gy

0 2 4 6 8 10

Fig. 2 Temporal changes in survival after high-LET
radiation in P. vanderplanki larvae. Closed circle: W-low,triangle: W-mid, diamond: W-high, open circle: D-high.

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JAEA-Review 2007-060

3-48 Study on Regeneration Mechanism of the Heavy-ion
Irradiated Hemopoietic Organ of the Silkworm,
Bombyx mori -Timing of Degradation and Regeneration of
the Irradiated Organ a)

a)

a)

a)

b)

b)

K. Shirai , T. Sakata , S. Tsuchiya , K. Kiguchi , K. Fukamoto , T. Sakashita ,
b)
b)
b)
b)
T. Kakizaki , T. Funayama , Y. Yokota and Y. Kobayashia)Faculty of Textile Science and Technology, Shinshu University, b) Radiation-Applied Biology
Division, QuBS, JAEA

Our previous studies elucidated that, in Bombyx mori, the hemopoietic organ disrupted by the heavy-ion irradiation, would
regenerate at wandering stage. This observation is a interesting phenomenon to investigate the hemopoietic stem cells in B.
mori. However, the detailed mechanisms for degradation or regeneration on the irradiated organs have been obscured. In thisstudy, the morphological changes of the hemopoietic organs after irradiation with 100Gy of carbon-ions at day 0 of 4th instar
were observed. In addition, the stage-specific marker proteins were also identified by 2-D electrophoresis followed bypeptide-mass fingerprinting (PMF).
The timings of degradation and regeneration of the organ irradiated at day 0 of 4th instar occurred at almost identicalstages to those of the organs irradiated at day 3 of 4th instar. These results predict that the developmental condition in larva,
including the hormonal condition, might influence the timing for the degradation and regeneration of the irradiated organ.
Two prominent protein spots were detected in the sample from the organs being disrupted (at day 2 of 5th instar) by 2D
electrophoresis. Those two proteins, estimated as soluble alkaline phosphatase and eIF 2 alfa kinase by PMF, would be
involved in the degradation process of the organ.
ほ乳類の細胞と比較して、一般に昆虫細胞は放射線照射に極めて耐性である。例えばカイコ幼虫の真皮細胞では表面線量400 Gyで炭素イオンを照射しても細胞死は認められない。その中で造血器官中の血球前駆細胞は、線量100 Gyで同じ炭素イオンを照射するとほとんど全ての細胞が致死・崩壊する比較的感受性の細胞である。ところが著者らは、炭素イオン照射により崩壊した造血器官が、その後、再生することを発見した。
本研究は重イオン照射されたカイコ幼虫造血器官の崩壊と再生の分子メカニズムを明らかにすることを目的にしている。これまでの研究では、重イオン照射後の造血器官の崩壊と再生の過程を調査し、さらにこの過程に体液中の循環血球が関与することを明らかにしてきた。平成 18 年度は、さらに詳細な分子メカニズ
ムを明らかにするため、今後の研究に必須となる造血器官再生のタイムテーブルの作製とステージ特異的な分子マーカーの探索を行った。
実験には著者らの研究室で継代飼育している着色非休眠系統のカイコ幼虫を供試した。重イオン照射は原子力機構TIARAで行った。照射に用いたイオン種および線量は、炭素イオン(12C5+、18.3 MeV/u、水中飛程：
約1.1 ㎜)で、線量は100 Gyである。照射はカイコ幼虫の造血器官に局部照射した。
照射後、一定時間ごとに造血器官を採取し、電子顕微鏡試料を作製し内部の細胞を観察した。また、採取した造血器官中のタンパク質成分を調査するため、一部の器官からタンパク質成分を抽出し成分を2次元電気泳動で分離・分析した。特に顕著に変化が認められた成分については、トリプシンで消化後、MALDITOF/MSを利用したpeptide-mass fingerprintingにより同定を試みた。
まず4齢day0の幼虫造血器官に重イオンを照射し、その後の造血器官の再生過程を経時的に観察した。その結果、以前報告した4齢催眠期（day3）幼虫に照射した場合とほぼ同じ過程が確認された。すなわち、照射を受けた造血器官は、一旦崩壊し、その後再生した。
当初、本実験は照射する幼虫の発育ステージを3日間早め、造血器官再生に十分な時間を確保することで、再生造血器官から産出される血球種を追究する予定であった。しかし、予想に反し、照射造血器官の崩壊・再生は大きく遅延し、照射時期を3日間早めたにも関わらず、4齢day3幼虫に照射した場合とほとんど同時期であった。この結果は、造血器官の再生が照射後の経過時間ではなく、幼虫の発育ステージに影響される
ことを示唆する。
次に、造血器官の再生過程をさらに詳細に研究する上で、必須と思われる各ステージ特異的な分子マーカーを得るため、重イオン照射造血器官のタンパク質
成分の経時的変化を2次元電気泳動で分析した。その結果、血球前駆細胞が致死・崩壊するステージである
5齢day 2幼虫から得た試料中で照射サンプルのみ大きくその量が増大する2つの成分が認め、peptide-massfingerprintingによる同定を試みた。その結果、これらの成分は可溶型のアルカリフォスファターゼおよび
eIF2αキナーゼと推定された。
現在、得られた結果をもとに、さらに詳細な重イオ
ン照射造血器官の崩壊と再生のタイムテーブルを作製中である。また、得られたステージ特異的マーカーについて、その関与を確認するとともに、造血器官崩壊期における役割について追究する予定である。

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JAEA-Review 2007-060

3-49 Influence of Local Irradiation with Heavy-ion
Microbeam on the Incidence of Somatic Mutation
Arising on the Larvae in Embryo and Yolk in the Egg of
the Silkworm, Bombyx mori
a)

a)

b)

c, d)

d, e)

T. Furusawa , E.Suzuki , S. Nagaoka , H. Suzuki , N. S. Ishioka, N. Hamada
f, g)
f, g)
f)
f)
f)
S. Wada , Y. Kobayashi , T. Sakashita , T. Kakizaki , T. Funayamaf)and K. Fukamoto
a)

f, g)

,

b)

Center for Bioresource Field Science, Kyoto Institute of Technology, Fujita Healthc)d)University, Japan Space Forum, Graduate School of Med. And Dental Sci, Kagoshimae)f)
University, Japan Aerospace Exploration Agency, Radiation-Applied Biology Division,g)
QuBS, JAEA, Department of Quantum Biology, and The 21st Century Center of
Excellence Program, Gunma University Graduate School of MedicineP

result in the significant incidence of mutation between
Kyoto and TIARA (Fig. 1).
In contrast, irradiation of 3 or 6 Gy to abodomen nearcaudal portion of embryo induced 63 % and 80 % ofsomatic mutation, respectively (Fig. 1).
In addition, irradiation of carbon beam to head had thealmost same level in the incidence of somatic mutation as
the control (non-irradiation), but the irradiation of 5 Gy toabdomen of embryo
induced 80 % of the incidence (Fig. 1). The white spots
appeared near the location which was hit by ion-beam.
From these results, it is not said that somatic mutation was
resulted by bystander effect.
90
Incidence of somatic mutation (%)

Irradiation of diapause eggs (heterozygote) with heavy
ion beam induces somatic mutation appearing as white spots
on the black integument during larval stage. The incidenceof the somatic mutation was clearly estimated as individuallevel dependently on both dose and LET1). The sensitivity
was the highest level during the first 2 days after resumptionof embryonic developments in the eggs, which terminateddiapause status. Low dose irradiation with 2 mGy could
induce the mutation 2).
It remains unclear whether the somatic mutation would
be induced by direct hit of the heavy particles to embryo, or
indirect hit to yolk surrounding the embryo by bystandareffect. This leads us to examine the incidence of the somatic
mutation by local hit of heavy ion particles to embryo or
yolk in Bombyx eggs.
The eggs (PS/p) were kept at 25 ℃ for first 10 days after
oviposition, and then at 5 ℃ for 70 days to terminate
diapasuse. These diapause-terminated eggs were transferredagain to 25 ℃ for resumption of embryonic development.
Carbon ion beam (3.0 Gy and 6.0 Gy) was irradiated to the
3-day old eggs after the resumption, and locally to 20μm2 of
the center (yolk) of the egg at 112 keV/μm and embryo at
119 keV/μm. After irradiation, the newly hatched larvae
were reared on an artificial diet throughout all stages, andwe counted the number of larvae with white spots on theblack integument to examine the incidence of the somatic
mutation.
For local irradiation, 10 eggs were lined up on verticaland horizontal line in 1 cm length each, namely 98 eggs
were placed on 1 cm2 of plastic film. But we did not place
eggs at left corner on the first upper line and at right corneron the 10th lowest line to set fix points on the coordinate.
The location of abdominal and caudal portion of embryo ineach egg was determined under microscope, and was input
in PC. According to this data, carbon ion-beam was hit on
the definite location on each egg.
We set up two controls, one is placed at Kyoto and theother is carried to TIARA to check the influence oftransport.
The incidence of the somatic mutation was 5 % in controlof Kyoto, and 12 % in TIARA (Fig. 1). However, theirradiations of 3 Gy and 6 Gy to the center of egg did not

80

a)

b)

c)

70
60
50
40
30
20
10
0
0
Kyoto

0
3
6
TIARA Center

3
6
AbdomenDose(Gy) and ir ar ia ted por tion

Fig. 1. Local irradiation of carbon beam to the silkworm
egg and the incidence of somatic mutation. a)
non-irradiated control of Kyoto(left) and TIARA(right), b) Center of egg, c) abdomen near caudal
portion of embryo.
References
1) E. Kotani et al., J. Radiat. Res. 43, (2002) S193.
2) T. Furusawa et al., Proceeding of the 48th Annual
Meeting of the Japan Radiat Res. Society, The 1st Asia
Cong. of Radiat. Res.(2005) 145.

－ 115 －

JAEA-Review 2007-060

3-50 Functional Analysis of Root Elongation Zone in
Hydrotropism in Arabidopsis Using Heavy-ion Microbeam
a)

b)

a)

a)

a)

a)

Y. Miyazawa , T. Sakashita , H. Negishi , A. Kobayashi , T. Kaneyasu , A. Ooba ,
a)
b)
b)
b, c)
b, c)
K. Morohashi , T. Kakizaki , T. Funayama , N. Hamada, S. Wada
,
b, c)
a)
a)
Y. Kobayashi, N. Fujii and H. Takahashia)b)Graduate School of Life Sciences, Tohoku University, Radiation-Applied Biology Division,c)
QuBS, JAEA, Department of Quantum Biology, and The 21st Century Center of Excellence
Program, Graduate School of Medicine, Gumma University

Previous studies on root hydrotropism suggest theimportance of auxin response at elongation zone, however,there has been no functional confirmation of thesenecessities in this response. To determine the responsible
tissue for root hydrotropism, it is necessary to inactivate thecell at desired position. Laser ablation of a specific cell canbe used for similar purpose, and in fact, it has been used todissect the functional role of root cap cells in gravitropism1.
Although this cell ablation is a powerful technique forunderstanding the function of certain cells, it is still difficult
to determine the role of elongation zone, since application ofthis method to this tissue leads the root to be snapped andbecome unsuitable to monitor the root curvature. To solve
this problem, we used heavy-ion microbeam irradiation for
nondestructive cell inactivation method. Although
irradiation with charged particles induce activation of
specific genes in mammalian cells, irradiation of heavycharged-particles with relatively high linear energy transfer
is thought to cause cell inactivation through induction of
DNA double strand breaks2. Recently, a device forheavy-ion microbeam irradiation with high precision has
been established, and used to determine the effect ofirradiation on root gravitropism3. However, theinterpretation of the effect of irradiation had been
ambiguous, because, to the best of our knowledge, no report
has demonstrated that irradiation of heavy-ion beaminactivates cellular processes by monitoring gene expressionof interest in plant cells. In this study, we investigated thepositional effect of cell inactivation by heavy-ion
microbeam irradiation with root hydrotropism, together withthe confirmation whether irradiation of heavy-ion beam
suppresses auxin-inducible gene expression in plant species.
First, we tested whether heavy-ion beam irradiation could
inactivate the cell, by investigating the alteration of
auxin-responsive gene expression by exogenously applied
auxin. In the following experiments, we used cold-run
seedlings (seedlings without irradiation) as control samples
to exclude the possibility that the experimental procedure
itself affects the gene expression levels and the phenomenon.
When control Arabidopsis seedlings were treated with 10-6
M indole acetic acid (IAA), 43.3-fold increase in theabundance of mRNA for auxin-responsive gene, namely
IAA5, was observed as compared with mock cultures. On theother hand, when Arabidopsis seedlings were systemically
irradiated by 220 MeV 12C5+ ion at a dose of 500 Gy, only

8.3-fold induction in the abundance of mRNA for IAA5 wasobserved, which is far less than control. This indicates thatthe heavy-ion beam irradiation causes the dull
responsiveness to exogenously applied auxin.
Next, we monitored the positional effect of heavy-ion
beam irradiation on root hydrotropic response by irradiatingwith 220 MeV 12C5+ ion at a dose of 500 Gy. We chose 180
μm aperture for irradiation so as to irradiate the whole partof elongation zone proximal to root tip. Control Arabidopsis
seedling roots responded to water potential gradient anddeveloped orthotropic curvature. When cells at elongation
zone proximal to root tip were exposed to heavy-ion
microbeam irradiation, hydrotropic response is significantly
repressed especially at the early phase of the hydrotropic
response (data not shown). Our present results indicatethat elongation zone profoundly affects the development ofhydrotropic curvature, probably involving de novo
auxin-responsible gene expression.

Figure 1. Effect of heavy-ion beam irradiation on auxin
responsiveness.
Total RNA extracted from either 12C5+-irradiated or
non-irradadiated samples was subjected to quantitative
reverse transcription PCR. The amount of IAA5 transcript
was normalized with ACT2 transcript level, and expressed as
relative value where the normalized IAA5 transcript level inauxin omitted samples was set as one. Open bars indicate
non-irradiated samples, whereas grey bars indicate irradiatedsamples. Data are the means of three independent
experiments ± SD. Note that statistically significant
difference was observed between two samples as calculatedusing Student’s two-tailed t-test (P < 0.05).
References
1) Blancaflor et al. Plant Physiol. 116 (1998): 213
2) Blakely Radiat. Environ. Biophys. 31 (1992) 181
3) Tanaka et al. J. Exp. Bot. 53 (2002) 683－ 116 －

JAEA-Review 2007-060

3-51 Differences in Circadian Rhythms of Resistance toγ-rays and Heavy-ion Beam in Euglena
a)

b)

b)

b)

A. Bolige , T. Sakashita , T. Kakizaki , T. Funayama ,
b, c)
b, c)
b, c)
d)
, S. Wada, Y. Kobayashi
and K. Goto
N. Hamadaa)b)United Graduate School of Agricultural Science, Iwate University, Radiation-Applied Biologyc)Division, QuBS, JAEA, Department of Quantum Biology, and The 21st Century Center ofd)Excellence Program, Gunma University Graduate School of Medicine, Laboratory of Biological
Rhythms, Obihiro University of Agriculture and Veterinary Medicine
The algal flagellate Euglena gracilis (Klebs Z) displays circadian rhythms in resistance to γ-rays and heavy-ion beams:
they persist for several days under continuous darkness at a constant temperature, and the most resistant phases occur 2-4 h
before subjective mid-days, at which circadian rhythms in UV resistance and anti-oxidative capacities become maximal. We
report here how these rhythms are related to each other. First, irradiation temperatures influenced neither survival after
exposure to UV, γ-rays, nor C ions, whereas the incubation at high temperatures (25˚C) after irradiation considerably
lowered the survival particularly after γ irradiation, but not after UV irradiation at all. Secondly, although the antioxidants βcarotene and dimethylsulfoxide (DMSO) increased the survival of the alga at the least resistant phase after UV-C and UV-B
irradiation, respectively, to the level of the most resistant alga, none of these were not so effective for γ- or C-ion-irradiation.
Instead, GSH, GSH-ethylester, l-cysteine and l-histidine increased the resistance to γ-irradiation, while the other set ofantioxidants did so for the resistance to C-ions. Particularly interesting was that the antioxidants l-ascorbate, N-acetyl-lcysteine, rutin, trolox increased the latter but not the former resistance. Finally, FITC-dextran was incorporated into the alga
only after C-ion irradiation but not γ irradiation, suggesting that C-ions may perforate cell membranes to kill the alga.
概日リズムは恒常環境の下ではその生物に固有な周期性（約２４時間；ユーグレナで２６時間）を表すとともに、昼夜の周期環境に同調して環境適応する。
ユーグレナ（Euglena gracilis Z）では、UVC耐性やUVB耐性、及び抗酸化能の全般（脂溶性and/or水溶性の一重項酸素消去能・ヒドロキシルラジカル消去能）が主観的真昼に最大となるよう概日リズムによって制御され、真昼に最大化する光酸化ストレスに対する予知的な防衛機能を果たしている。γ線や220 MeV 12Ｃ
イオン（以下Ｃイオン）に対してもユーグレナは同様の概日リズムを示すが、その最大耐性は主観的真昼にはなく、2～4時間ほど先行した形をとる。この放射線耐性リズムと同一位相で走る抗酸化能リズムも振幅は小さいながら認められる。
実験にはユーグレナを6～8万細胞/mL になるまで
25 ℃、6 klx 恒明（白色蛍光灯）で培養し、恒暗に移す。恒暗中の様々な時点でγ線や220 MeV 12Ｃイオン（以下Ｃイオン）を照射し、中性赤を用いて生死判別を行った。その生存率をもって耐性の基準とした（Ｃ
イオンは照射直後、γ線は一日後）。
γ線とＣイオン照射を行う温度（0、25 ℃）は生存率に影響しない。これはＵＶ照射の場合も同様である。
これに対し、照射後に低温（4 ℃）放置した場合には、25℃で保存した場合より10～60 ％ほど高い生存率を示し、温度依存的な生命活動が死を促進する可能性が示された。このことは、γ線照射の場合により顕著に認められる。ＵＶ照射の場合は細胞死はすべて照射中及び直後にのみ生起するので、この点については比較対照外である。γ線耐性増強には還元型グルタチオン、GSH－エチルエステル、システイン、ヒスチジンなどが有効であった。また、β―カロテンやリコピンも少なからず有効であった。
Ｃイオン耐性増強に有効であったのはシステイン、N－アセチルシステイン、ルチン、アスコルビン酸、還元型グルタチオン、GSH－エチルエステル、トロ
ロックス、β―カロテンやリコピンなどの抗酸化剤である。したがって、γ線耐性やＣイオン耐性には水溶性や脂溶性のラジカル消去能と一重項酸素消去能が総合的に関与しているものと考えられる。ただし、両耐性は互いに異なる抗酸化機作も関係している。例えば、
γ線耐性増強に有効な抗酸化剤はＣイオン耐性増強にも有効であったが、逆にＣイオン耐性増強に有効なア
スコルビン酸、N－アセチルシステイン、ルチン、トロロックスなどはγ線耐性増強には殆ど無効だからである。また、還元型グルタチオン、システインやβ―カロテンを含む抗酸化剤の組み合わせ投与により、600 Gy程度の低線量照射の場合、γ線耐性もＣイオン耐性も非酵素的な抗酸化能だけで説明できるが、高線量照射の場合には、抗酸化能以外の要因も関係している可能性が示された。更に、分子量の異なるFITC－デキストランを用い、放射線によるユーグレナの死滅に細胞膜の物理的損傷の有無を調べたところ、γ線照射の場合には高線量でもFITC－デキストランを透過させるほどの損傷は生じないことが明らかになった。これに対し、Ｃイオン照射の場合には1,500 Gy 以上の線量でFITC-デキストランの取り込みが顕著に確認された： 10 kDのもので50 %のユーグレナに, 20 kDで1015 %のユーグレナに取り込まれる。したがって、Ｃイオン照射による致死作用には物理的生体膜損傷が関与していると考えられる。この致死作用に抗酸化剤は殆ど無効である点も、高線量Ｃイオン耐性には抗酸化能は無縁であるという上記事実と符合している。

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JAEA-Review 2007-060

3-52 Detection of Damage Using ESR Method to IrradiatedWheat Flour
a)

a)

a)

b)

c)

c)

M. Ukai , M. Matsuura , S. Ogawa , T. Kume , M. Kikuchi , T. Sakashita ,c)c)T. Funayama and Y. Kobayashi
a)

b)

c)

Hokkaido University of Education, TARRI, JAEA, Radiation-Applied Biology Division,
QuBS, JAEA

Irradiation of food is a non-thermal treatment and amethod of cold pasteurization. This pasteurization techniqueretains the quality of foods as prepared and harvested.
Recently, the use of this sterilization technology by
irradiation through various electromagnetic waves or rays ofelementary particles is gaining wide applications. Since
irradiation induces free radicals, consumer believes that
irradiated foods can be the threatening of public health.
Electron spin resonance (ESR) spectroscopy has been
applied for the evaluation of irradiation on the wide variety
of foods. We have reported on a new ESR protocol for the
analysis for irradiated foods1).
In the present study, we will report on theradiation-induced radicals containing in wheat flour using
ESR spectroscopy. We shall describe new radical species in
the irradiated wheat flour by comparison with non-irradiatedwheat flour. Attempts have been made on the irradiation
damage of radicals.
The flour sample of wheat was the products of Gumma,
Japan. The nutritional contents of the wheat flour consist of
starch (70 wt %) and protein (14 wt %). In order to avoid theanisotropic EPR spectral dependence by the microcrystallineof grain in wheat flour, we employed a separation method of
powder sizes of less than the 200 meshes. Thereby, theidentical ESR signals were detectable irrespective of thesample tube rotation. The specimens were irradiated at the
JAEA Takasaki at room temperature (ca. 20 ºC). The dosage
level of the gamma ray was controlled by the irradiation
period. We selected the three dose levels, i.e., 10, 30 and 50
kGy.

ESR measurements were carried out using an ESR
spectrometer (Jeol, JES-FE1XG and JFS-FA200). All the
ESR spectra were recorded at the X-band (9.3 GHz). In
order to detect full view of all the radical species of wheat
flour, we employed two kinds of field sweep, 250 ± 250 mT
and 320 ± 100 mT.
The ESR spectrum of wheat flour before irradiationconsists of a sextet centered at g = 2.0 and a singlet signal at
the same g-value position (Fig.1). The first one is
attributable to a signal with hyperfine (hf) interactions of
Mn2+ ion (hf constant: 7.4 mT). The second is originatedfrom carbon-centered radical.
Upon gamma ray irradiation, however, a new signal with
two triplet lines at the low and high field ends was detected
in wheat flour on top of the Mn2+ sextet lines (Fig.2). We
analyzed the triplet ESR lines as powder spectra (rhombic
g-tensor symmetry) with nitrogen (14N) hyperfine
interactions. This indicates that a new organic radical was
induced in the conjugated protein portion of wheat flour by
the gamma ray irradiation. Intensity of the organic free
radical at g = 2.0 detected in irradiated wheat flour increased
with the degree of irradiation.
Reference
1) M. Ukai, et al. Appl. Magn. Reson., 24 (2003) 1.

1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8

Fig.1 Anisotropic ESR spectra from wheat flour before
irradiation. Different signals were observed by the

-1
2900

3400

Fig.2 ESR signal of irradiated wheat flour (50k Gy).

rotation of ESR sample tube containing wheat flour.

－ 118 －3900

JAEA-Review 2007-060

3-53 Preparation of Acellular Arteries by Gamma Irradiation
a)

b)

b)

b)

b)

c)

T. Fujisato , M. Kikuchi , T. Sakashita , T. Funayama , Y. Kobayashi , S. Funamoto ,c)c)d)T. Kimura , A. Kishida and T. Yamaokaa)Department of Biomedical Engineering, Osaka Institute of Technology,b)
Radiation-Applied Biology Division, QuBS, JAEA,
c)
Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University,d)Department of Biomedical Engineering, National Cardiovascular Center Research Institute
Synthetic materials, such as ePTFE or Dacron are not suitable for reconstructing the small-diameter arteries. In contrast,
tissue engineering (TE) graft has been attracting great attention recently. One of the promising approaches of TE grafts isusing acellular tissues. The acellular scaffold may have the same structure and characteristics as the natural tissue and can be
replaced with the host tissues. In this study, we prepared the acellular scaffold using gamma irradiation, which is expected
to induce the apoptosis of the cells.
現在、我が国において人工心臓弁は年間１万個、人工血管は５万本が使用されている。屍体から提供されるヒト心臓弁や血管も組織バンクを通じて臨床使用されているが、年間数十件程度に過ぎない。米国では商業利用によって、年間数千件のヒト組織が使用されている。人工素材から作製される移植用組織は生体にとっては異物であり、自己組織と置き換わることはな
い。また、小児患者においては体の生育に伴った成長性が欠如しているという欠点もある。近年、移植後の拒絶反応を避けるために、自己組織と置換される素材を用いた組織再建が臨床応用され始め、東京女子医大グループによる生体内分解吸収性材料を用いた再生型
血管や、ドイツ・フンボルト大学グループによるブタ
脱細胞化組織を用いた再生型心臓弁が報告されている。
我々は、放射線照射によって細胞を除去した生体組織をバイオスキャホールド（細胞足場材料）として用いた再生型移植用組織の開発を行っている。
移植組織片は以下のようにして作製した。生後４ヶ月、体重約10 kgのクラウン系ミニブタ（㈱ジャパン
ファーム、鹿児島）から清潔下にて下行大動脈を採取した。PBSによる洗浄後、PBSを満たした滅菌容器に封入し、10，30，100，300，あるいは1000 Gyのガンマ線を高崎量子応用研究所のCo-60照射施設を用いて照射した。吸収線量率は、それぞれ100，300，100，300，
1000 Gy/hである。照射後、PBSをベースとする洗浄液
にて２週間洗浄した。洗浄液は、適宜交換した。
Wisterラット（７週令）の皮下部位に上記脱細胞化ミ
ニブタ大動脈を埋入し、２週間後に取り出し、ヘマト
キシリン－エオジン（HE）染色、マクロファージに対するCD68免疫染色にて組織学的検討を行った。
種々のガンマ線量による組織脱細胞化の基礎的検討
を残存DNA定量試験、力学試験にて行った結果、残存DNA定量試験では、100あるいは300 Gy以上の照射では大幅なDNA減少傾向が見られた。また、力学特性は、破断強度並びに弾性率とも大きな影響は見られなかった。すなわち、300 Gy以上のガンマ線を照射後、洗浄処理することによって、循環器系組織内の細胞はほぼ完全に除去できると思われた。
次に、ガンマ線照射によって作製した脱細胞化ミニ
ブタ大動脈の有効性を、ラット皮下への埋入試験により、組織学的、免疫組織学的検討を行った。ガンマ線
未照射ミニブタ大動脈の場合、ラット由来の血管の流入が認められた。一方、1000 Gyのガンマ線照射脱細胞化ミニブタ大動脈では、血管の流入は確認されなかった。HE組織染色結果からは、ガンマ線未照射ミニ
ブタ大動脈では、組織反応による細胞の浸潤が見られたが、1000 Gyのガンマ線照射脱細胞化ミニブタ大動
脈では、細胞浸潤は認められなかった。
また、移植片を免疫染色によって評価した結果、未処理血管では、マクロファージ陽性を示すCD68陽性部
位が多く見られるのに対して、ガンマ線照射脱細胞化
血管では、炎症部位の減少が示された。これら染色画像について画像解析ソフトを用いてCD68陽性細胞面積を計測した。その結果、未処理血管では、炎症細胞が多く存在していたが、ガンマ線照射の組織では炎症細胞が有意に減少していた。

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JAEA-Review 2007-060

3-54 Molecular Imaging by Using Positron Emitting Tracer
Imaging System (PETIS) to Study Plant Physiology;
Parametric Imaging of Photosynthesis
N. Kawachi, S. Fujimaki, S. Ishii, N. Suzui, N. S. Ishioka and S. Matsuhashi
Radiation-Applied Biology Division, QuBS, JAEA
Radionuclide-based imaging techniques enable us toobtain images of the kinetics of the transport of water andnutrients in plants, and hence determine plant physiology. In
particular, by using the positron-emitting tracer imaging
system (PETIS), which was designed for studying plant
physiology and agriculture, many experiments have been
performed for the imaging of the distribution andtranslocation of the nutrients using positron emitting tracers.
The kinetics of 11C make it a potential candidate for
estimating the physiological function parameters ofphotosynthesis. By using 11CO2, the kinetics ofphotoassimilation and of the flow of sucrose, which issynthesized as a photosynthate, through sieve tubes havebeen obtained as movies comprising serial images. We haveanalyzed the exchange of carbon compounds inside andoutside a test leaf, based on the 11C-labeled tracer kinetics inthe compartmental model. An analytical solution of the
carbon tracer balance was obtained by the following
equation; as follow;

L(t ) = K1 • Ci (t ) ⊗ e − ( k 3+λ ) t(Eq. 1)

where, L(t) is the leaf response time-activity curve, whichindicates the time variation of 11C concentration in leaf;
Ci(t), the input time-activity curve; λ, the physical decay of
11
C; and ⊗ , the convolution integral. Further,photoassimilation (K1) and the sucrose export (k3) rate
constant were estimated by kinetic analysis1).
In order to produce parametric images of photosynthetic
functions from the PETIS movie data, we performed apixel-by-pixel analysis by the present compartmental

method.
To
construct
theimagesdepictingphotoassimilation and the sucrose-export images from theestimated values of the parameters K1 and k3,
approximately 10,000 pairs of time-activity curves werefitted to the Eq. 1 by the nonlinear least squares method. By
this analytical method, 2 bioactive distribution images were
produced from a single movie data.
Shown in Fig. 1 are the parametric images of 2
photosynthetic processes namely, photo-assimilation andsucrose export. The K1 image indicates thatphotoassimilation was distributed uniformly over the entire
leaf. In contrast, the k3 image indicates that sucrose export
was not distributed uniformly. The sucrose export ability at
the tip was greater than that at the base. This seems
attributed to the well-known fact that the base of the leaf isthe region of growth. It implies that sucrose produced at thebase of the leaf was probably consumed there itself for thegrowth, and that produced at the tip was mainly transported
to the other parts of the plant.
In summary, we have performed imaging using PETIS
and kinetic analysis for studying the processes of plant
physiology, such as photosynthesis in living systems mainly
in response to the environment, and processes involved in
the anisotropic maturation of leaf tissues 2).
References
1) N. Kawachi et al., IEEE Trans. Nucl. Sci., 53 (2006)
2991.
2) N. Kawachi et al., IEEE Nucl. Sci. Symp. C. R., 5 (2006)
151.

Fig. 1 Parametric images of photosynthetic functions. The left image on the left indicates the distribution of photoassimilation (K1) and the image on the right indicates the distribution of sucrose export in different regions of the leaf
(k3).

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JAEA-Review 2007-060

3-55 Non-invasive Estimation of Phloem Flow Velocity underCadmium Stress Using the Positron Emitting Tracer
Imaging System
a)

a)

a)

b)

a)

N. Suzui , N. Kawachi , S. Ishii , S. Nakamura , S. Matsuhashi and S. Fujimakia)a)Radiation-Applied Biology Division, QuBS, JAEA,
Faculty of Bioresource Sciences, Akita Prefectural Universityb)

Cadmium (Cd) is a major environmental pollutant,which accumulates in agricultural soils, and is a toxic
element to all organisms. In plant, the most sensitive
symptom of Cd toxicity is stomata closure, followed by the
inhibition of photosynthesis. However, it has been reported
that Cd treatment increases carbohydrate content of source
organ. This contradictory result could be due to theinhibition of translocation of photoassimilates by Cd.
However, direct evidence has not been reported.
In this study, we estimated a phloem flow under Cdstress using the positron emitting tracer imaging system(PETIS), quantitatively and non-invasively. In an
experiment, 11CO2 was supplied to leaves of rice plants andthe translocations of 11C- photoassimilates were monitored.
Rice plants (Oryza sativa L. cv Nipponbare) were
germinated and grown hydroponically in nutrient solution(without Cd) for 4 weeks. Plants were transferred to thenutrient solution containing 0 (control), 1, 10 and 100 μ
M of Cd, and cultured for 1 day before PETIS experiment.
Five to six of Cd-treated plants were placed between a
set of PETIS detectors in a growth chamber. The upper
half of the largest expanded leaf of each plants wasinserted into a "gas-cell", a clear acrylic box for feeding
11
CO2 (100 MBq) gas (Fig.1). Time course of11
C-radioactivity (Time-Activity Curve) in the basal region
was generated from the serial images of each rice plant(Fig.1). The value of the x-axis intercept of approximatedline was defined as 11C-arrival time to basal region.
We performed 6 sets of PETIS experiments using 5 ~ 6
different rice plants treated with 0, 1, 10, 100 µM of Cd.
The arrival times of 11C-photoassimilates to the basal
region of each plant were analyzed (Fig. 2). Phloem flow
velocities were also estimated using the 11C-arrival time
and the distance from the bottom of gas-cell to the basal
region.
Arrival time of 100 µM Cd-treated plants was
significantly different from that of control and 10 µM
Cd-treated plants (p < 0.05). This result indicates that Cd
exposure for 1 day causes the decrease of phloem flow
velocity in rice plant. Now we are also examining the rateof photoassimilation in source leaf and the concentration ofphotoassimilates in phloem sap under Cd stress. These data
will provide the basis of Cd toxicity to plant.
This study indicates the utility of estimation of phloem
flow velocity using PETIS and simple data analysis. Thismethod can be applied for studying influences on phloem
transport against other environmental conditions.

Fig.1 Time-Activity Curve for accumulation of 11Cphotoassimilates in the basal region of rice plants
treated with 0, 1, 10, 100 µM of Cd. The figure on theleft shows the image of 11C-radioactivity captured by
PETIS and the picture of tested plants.

Fig.2 Effect of Cd stress on 11C-arrival time to basal region.
Means with the same letter are not significantly different(p < 0.05). n=7~8－ 121 －

JAEA-Review 2007-060

3-56 The Imaging of Translocation of Major Nutrition Using
the Positron Emitting Tracer Imaging System
S. Ishii, N. Kawachi, N. Suzui, S. Fujimaki and S. Matsuhashi
Radiation-Applied Biology Division, QuBS, JAEA
Nitric acid and ammonium absorbed by the roots, andcarbon dioxide fixed on the leaves, are metabolized,
distributed and accumulated into the plant organs.
Correlation between carbon assimilation and nitrogenassimilation is one of the important factors regulating plant
growth 1, 2).The Positron-Emitting Tracer Imaging System(PETIS) and tracers of major nutrition have been an
available system to obtain movies of tracer in short-term
distribution non-invasively. Therefore, we tried to visualize
the movement of carbon and nitrogen nutrition in a wholeplant.
Soybean (Glycine max [L.] Merr. cv. Enrei) plant
inoculated with rhizobium had been hydroponically cultured
with MS medium for 25 days, and was used for the PETIS
experiment (Fig.1). Three tracers, 11CO2, 13NO3- and 13NH4+
were produced by bombarding targets (11CO2: nitrogen gas,
13
NO3-: pure water, 13NH4+: pure water with a small amountof ethanol) with proton beam delivered from the TIARA
AVF cyclotron. Soon after approximately 30 MBq of 11CO2
was fed to the leaves, PETIS images were acquired for 2
hours. After first imaging, 100 MBq of 13NO3- was fed to
the roots and PETIS images were acquired for 90 min.
Subsequently, 16 MBq of 13NH4+ was fed to the roots anda)images were acquired for 90 min. The interval of each
imaging was about 30 min to allow radioactivity to decay atthe background level.
As a result, a movie of distribution of 11C-labeled
photoassimilates in the plant organs and nodules, andmovies of translocations with 13NO3- and 13NH4+ wereacquired (Fig.2). In other words, the real time imaging oftranslocation of 11C labeled carbon source and 13N labelednitrogen in an intact nodulated soybean plant wasdemonstrated.
Furthermore, nitrogen fixed by nodule was importantfactor regulating plant growth in soybean plant. An imaging
experiment on N2 fixation of nodule and fixed nitrogentranslocation in soybean is currently in progress by using
PETIS and 13N2 gas.
References
1) H. Fujikake et al. J Exp Bot. 2003 May; 54 (386) 1379
2) S. Ito, N. Ohtake, K. Sueyoshi and T. Ohyama
Soil Science and Plant Nutrition 52 (2006) 438

b)

c)

11

CO2

13

Fig.1

NO3-,13NH４+

Setting of PETIS
experiment.
Soybean plant was fixed onacrylic plate. 11CO2 was fed toleaves covered with acrylic
gas cell. The roots were
soaked in hydroponic solution
in plastic bag. 13NO3- 13NH4+,
were mixed with hydroponicsolution.

Fig.2 The Serial images from the PETIS experiments.11C scan sequence was 7.5 min
and 13N scan sequence was 4.5 min. All images were corrected for the radioactive
decay of each tracer. Images were arranged sequentially from left to right and top tobottom. a) 11CO2 exposure to leaves. b) 13NO3- absorption by root. c) 13NH4+
absorption by root.

－ 122 －

JAEA-Review 2007-060

3-57 Non-invasive Imaging of Cadmium Long-distanceTransport in Higher Plants
a)

b)

b)

b)

a)

S. Nakamura , N. Suzui , N.S. Ishioka , N. Kawachi , M. Chino , S. Matsuhashib)and S. Fujimakib)a)Faculty of Bioresource Sciences, Akita Prefectural University,b)
Radiation-Applied Biology Division, QuBS, JAEA

Cadmium (Cd) is a harmful heavy metal element. It
causes various obstacles in the human body when it is taken
in via the food. Cd is also famous as a causative substanceof the itai-itai disease. Recently, there is the international
movement which makes the reference level of cadmium
content in the food harsh. It has become national urgent
business to establish the agricultural technology which
decreases the cadmium content in the farm products.
In order to decrease the cadmium content in the farm
products, two technologies are focused recently. One iscalled “phytoremediation” which cleans up the cultivationsoil using absorption by special plants. The other is tomodify the crop plants not to accumulate cadmium in theiredible parts. However, these technologies are not practicalyet. For realization of these technologies, it is necessary to
elucidate the mechanism of transport of Cd in the plantbody.
In this research, we visualized Cd transport in the plant
body by using Positron Emitting Tracer Imaging System(PETIS). We tried to elucidate the mechanism of Cd
transport in the whole plants by analyzing the experimental
data which is obtained by PETIS.
107
Cd which is positron-emitting nuclide was used for
PETIS experiment. Production method of 107Cd wasestablished by Ishioka et al.1). Sorghum plants (Sorghum
vulgare L.) and oilseed rape plants (Brassica napus L.) weregrown hydroponically for two weeks after sowing. PETIS
experiment was performed inside the growth chamber where
we can control growth conditions of plants completely.

Fig. 1 Accumulation of 107Cd signals in sorghum plants.
This image is integration of 15 original frames,
corresponding to 1 hour (From 23 hour to 24 hour
after the start of the experiment).

After setting plants inside the chamber, PETIS experiment
was started by adding purified 107Cd in hydroponic solutions.
Time-series images of the 107Cd distribution in the aerialpart and upper part of the roots of plants were obtained with
the PETIS apparatus. Time courses of the absorption ofwater and the tracer (107Cd) by plants were also monitored.
Time-activity curves, temporal changes of the tracer amountin specific regions of interest (leaves, stems, and so on)were generated from PETIS data. These data were combined
and analyzed.
We succeeded to obtain fine serial images of Cd transport
in sorghum plants (Fig. 1) and oilseed rape plants (Fig. 2).
We could observe that 107Cd signals arrive in the aerial partsof both plants in a few hours after the start of the experiment.
Patterns of accumulation of 107Cd signals in sorghum plants
were similar to those in rice plants2). Strong signals of107
Cd were seen in the basal region of the shoot, which
consists of a short stem, nodes and meristems. Interestingly,
107
Cd also accumulated in the node strongly in oilseed rape
plants although these two plants have different structure as a
monocot and a dicot. The analysis of time-activity curves
revealed that pattern of accumulation of 107Cd changes indevelopment in the oilseed rape plants.
References
1) N. S. Ishioka et al., JAEA Takasaki Ann.Rep. 2005
(2006) 162.
2) S. Fujimaki et al., JAEA Takasaki Ann.Rep. 2005
(2006) 127.

Fig. 2 Accumulation of 107Cd signals in oilseed rape
plants. This image is integration of 15 originalframes, corresponding to 1 hour (From 23 hour to 24
hour after the start of the experiment).

－ 123 －

JAEA-Review 2007-060

3-58 Imaging of Translocation and Spatial Distribution of theAssimilated Carbon and Nitrogen in the Host–root
Parasite System by PETIS
a)

b)

a)

a)

a)

a)

H. Sekimoto , N. Kawachi , S.Honda , Y. Yamaguchi , S. Kato , K. Yoneyama ,
b)
b)
b)
b)
b)
b)
S.Fujimaki , N. Suzui , S. Ishii , S. Watanabe , N. S. Ishioka , H. Sutohb)and S. Matsuhashia)Faculty of Agriculture, Utsunomiya University
Radiation-Applied Biology Division, QuBS, JAEA

b)

Translocation and distribution of 11CO2, 13N-nitrate or
N-ammonium in the red clover (Trifolium pratense L.)parasitized by small broomrape (Orobanche minor Sm.) was
examined by PETIS. The PETIS images acquired
periodically after 11CO2 exposure indicate that Orobanche isa big ‘sink’ of the assimilated 11CO2 by host plant.
Accumulation of 13N applied as 13NH4+ in Orobanche
tubercles was higher than that applied as 13NO3–, indicatingthat 13NH4+ stay longer in Orobanche tubercles than 13NO3-.
The differences in the accumulation may be due to the rapid
metabolism of ammonium to amino acids.
Sharing
photoassimilates
andabsorbed
nitrogen-compounds with host plants is of primary
importance for the survival of root parasites. Direct
imaging of translocation and spatial distribution of theassimilated carbon and nitrogen in the host–parasite systemis the most convincing approach for the study ofhost–parasite interactions. However, each host-parasite
system is unique and may be different from others, andtherefore, it is quite difficult to obtain reproducible results.
Consequently, a noninvasive and repeatable imaging systemusing the radioactive nuclides having short half-lives isneeded. The positron-emitting tracer imaging system(PETIS), designed for the use in plant science to study thetranslocation and distribution of nutrients by using
radioisotope tracers (11C, 13N, etc), allows us to performnoninvasive, repeatable, and quantitative analyses ofnutritional sharing between host plants and root parasites. In
the present study, translocation and distribution of 11CO2,
13
N-nitrate or 13N-ammonium in the red clover (Trifolium
pratense L.) parasitized by small broomrape (Orobanche
minor Sm.) was examined by PETIS.
The PETIS images acquired periodically after 11CO2
exposure indicate that Orobanche is a big ‘sink’ of theassimilated 11CO2 by host plant (Fig.1). Based on theimage analysis of the 11C radioactivity in the host–parasite
system, 15% of the carbon assimilated by host plant
accumulated in Orobanche 30 to 40 min after the 11CO2
exposure. In addition, It seemed that Orobanche tubercles
absorbed 13NH4+ more strongly than 13NO3–, indicating that13
NH4+ stay longer in Orobanche tubercles than 13NO3(Fig.2). However, relative ratios of radioactivity in
Orobanche tubercles to that in the root area were very
similar in both the 13NO3–- and 13NH4+-fed host–parasite
13

systems, suggesting that Orobanche tubercles absorb 13NH4+
and 13NO3– with similar affinities. The differences in theaccumulation may be due to the rapid metabolism ofammonium to amino acids.

120 min.
Orobanche

Fig.1 11CO2 translocation and distribution in the Orobanche
infected plants

Orobancheno-infected
infected
13

NO3–

13

NH4+

Basal shoot

90min
Orobanche
Fig.2. 13NO3- (above) and 13NH4+ (below) translocation anddistribution in the Orobanche infected plant－ 124 －

JAEA-Review 2007-060

3-59 52Fe and 62Zn Translocation from the Roots to the
Shoots of Rice Monitored by Positron Emitting Tracer
Imaging System (PETIS)a)

H. Nakanishi , T. Tsukamotob), c)

c)c), S. Watanabe , S. Matsuhashi , N. K. Nishizawa
a)and S. Mori

a)

b)

b)

Department of Applied Biological Chemistry, The University of Tokyo, Department ofc)Global Agricultural Sciences, The University of Tokyo, Radiation-Applied Biology
Division, QuBS, JAEA,

1. Introduction
Iron (Fe) and zinc (Zn) are essential nutrients for plants.
However, little is known how Fe and Zn are translocated inrice plants especially to the ear after absorption from roots.
In addition, the real-time measurement of translocation of
Fe and Zn has not been documented in plants. To study thepathway of Fe and Zn to the ear, we traced 52Fe and 62Zn inrice plants (Oryza sativa L. cv. Nipponbare) of 3 weeks
after flowering by positron emitting tracer imaging system(PETIS).
2. Experimental procedure
Rice (Oriza sativa L. cv. Nipponbare) werehydroponically cultured in a growth chamber under amixture of incandescent and fluorescent lamps with a 14 h
light (30 °C)/10 h dark (25 °C) regime and a photon flux
density of 320 μmol m-2 s-1. The nutrient solution was
renewed once a week. The absorption experiments were
performed about 3 months after germination and 3 weeks
after flowering. A rice plant was supplied with 20 mL ofculture solution in polyethylene bags. The plants and thebags were fixed an acrylic board and placed between a pairof PETIS detectors in a chamber at 30 °C under 65 %humidity and a light density of 320 µmol m-2 s-1.
Fe3+-deoxymugineic acid (DMA) (about 2 MBq) or 62Zn2+(about 20 MBq) were added to culture solution. The shoots
were monitored by PETIS for 14 h.
52

3. Results and discussion
In order to clarify the pathway of Fe and Zn from theroots to the ear of rice, 52Fe3+-DMA or 62Zn2+ was fed toroots of a rice plant, and translocation of 52Fe or 62Zn wasmonitored using PETIS method. 52Fe and 62Zn wastranslocated to shoots within 14 h (Fig. 1, Fig. 2). In
particular, the nodes were strongly labeled. Both 52Fe and62
Zn were preferentially accumulated in the lower node until
2 h and 5 h after absorption, respectively. However, theradioactivity of upper node was higher than that of lower
node in the last results. It was reported that the nodes
contained the elliptical, diffuse and anastomosing vascularbundles, and the xylem transfer cells were found in theelliptical bundles1). Therefore, 52Fe and 62Zn might betransferred from xylem to phloem in the nodes.
Reference
1) S. Y. Zee et al., Aust. J. Bot. 20 (1972) 41.

Fig. 1 52Fe translocation to the shoots of rice. (A)Accumulative PETIS image. (B) Gross image of rice
plant. (C) Time course of radioactivity of 52Fe in thenodes.

－ 125 －

Fig. 2 62Zn translocation to the shoots of rice. (A)Accumulative PETIS image. (B) Gross image of rice
plant. (C) Time course of radioactivity of 62Zn in thenodes.

JAEA-Review 2007-060

3-60 Impact of Aluminum on the Photosynthesis andTranslocation of Photoassimilats in Rice Seedling.
-Imaging-based Analysis by PETISa)

b)

b)

b)

b)

b)

T. Furuichi , S. Fujimaki , N. Kawachi , N. Suzui , S. Ishii , N. S. Ishioka ,
b)
b)
a)
c)
H. Sutoh , S. Matsuhashi , M. Sokabe and Y. Yamamotoa)

Graduate School of Medicine, Nagoya University
Radiation-Applied Biology Division, QuBS, JAEA
c)
Research Institute for Bioresources, Okayama Universityb)

Accumulation, translocation and distribution of
C-labeled photoassimilates in the rice (Oriza sativa. cv.
Nipponbare) seedling treated with or without aluminum (Al)was examined by PETIS. The PETIS images acquired
periodically after 11CO2 exposure indicate that the long-term
exposure promote the accumulation of 11C-labeled
photoassimilates and its translocation toward roots. In
contrast, the short-term exposure attenuate both. Similar
results were observed in the seedlings of tobacco, suggestthat Al-dependent modulation on the rate of photosynthesis
and thefollowing translocationof 11C-labeled
photoassimilates is the common feature of land plants.
Thirty to 40 % of arable land in the world has been
estimated to be acidic soils. In addition global
industrialization has triggered huge exhaustion of acidic
compounds into the atmosphere, which expanded the area ofacidic soils in all over the world. In the regions where acidic
soils are prominent, most of the crops or pastures are
disturbed their growth and development. Aluminum (Al), themost abundant metal element in soils, is solubilized as freeions under acidic conditions and exhibits toxicity to plants. A
variety of plants can grow in acidic soils by secretion oforganic acids from root apices, which excludes and/or
detoxifies Al ion in the apoplast. To support the efflux oforganic acid from root apecies under al stress, sugars shouldbe transported to the root apecies, but how the rate andamount of sugar-translocation are regulated is still obscure.
To understand that, 11CO2 was applied to the entire seedlings
which settled in a air-tight clear-acrylic box (inside
dimensions: 8 cm in length, 5 cm in width, 1 cm in depth),
and the box was positioned in the middle of the PETIS
detectors. In rice seedlings, a major crop of monocots, werepre-treated with Al, 11CO2 fixation and sugar translocation
toward roots were enhanced by the long-term exposure (31.5h) to AlCl3 (100 µM) in acidic condition. In contrast,
relatively short-term exposure (25.5 h) attenuate those andthose were recovered in transition state (28.5 h), as observedin tobacco seedlings (reported in the previous report)(Fig.1).
These results suggest that the stimulation of photosynthesis
in leaves by Al exposure to roots and subsequenttranslocation of photoassimilates toward root part is acommon feature of both dicots and monocots.
11

25 .5 Hrs

28 .5 Hrs

31 .5 Hrs

Fig.1
Aluminum-dependent
modulationofphotoassimilates-distributioninriceseedlings.
Hydropotonically-grown rice seedlings (20-day old)
were treated without (control, right two in each panel)or with 100 µM AlCl3 (+Al, left two in each panel) in
modified Ruakura medium (pH 4.3) for the indicateddulations. Then the entire seedlings were expose to
11
11
CO2,
and
the
distributionofC-labeledphotoassimilates was monitored for 120 min. The
radioactive counts integrated for every 12 min from astart till 120 min are shown.

－ 126 －

JAEA-Review 2007-060

3-61 Cyclotron Production of PET Radionuclide:
No-carrier-added Bromine-76 with Protons on Natural
SeO2 and KBr Targetsa)a)b), c)

a)N.S. Ishioka , Sh. Watanabe , Y. Iida
, H. Suto , H. Hanaokaa)c), d)
a)and S. Matsuhashi
N. Suzui , K. Endoa)b), c), H. Yoshiokac), d),b)

Radiation-Applied Biology Division, QuBS, JAEA, Bioimaging Information Analysis, Gunmac)
University Graduate School of Medicine, The 21st Century COE Program for Biomedicald)Research Using Accelerator Technology, Diagnostic Radiology and Nuclear Medicine, Gunma
University Graduate School of Medicine

In recent years Positron Emission Tomography (PET) has
become established as particularly attractive tracer forcancer detection using positron-emitter. The increasing useof PET for clinical diagnosis, drug development andbiological research has prompted many chemists to develop
new labeling and purification methods. The PET
radionuclides such as 11C, 13N, 15O and 18F have been used
for imaging agent, which are short half-lives; 18F with thelongest half - life is 110 minutes. On the other hand, thepositron-emitter with a longer half-life that can be applied to
the PET diagnosis based on a nuclear characteristic is
proposed besides above-mentioned nuclides. 76Br is ofpotential interest in nuclear medicine: 76Br has beensuggested as a halogen label with a convenient half-life (T1/2= 16.1 h) and a sufficient β-branching ratio (57.2 %) in PET.
Here we present the development of a direct and an indirect
production methods for 76Br.
76
Br was produced from the direct and indirect nuclear
reactions (76Se(p,n)76Br, 79Br(p,4n)76Kr (T1/2: 4.6 h)→76Br).
In the direct method, 6 ml of SeO2 solution with the natural
isotope composition was irradiated for 20-30 minutes with
proton beams (20 MeV) of 1μA. The generated 76Br was
separated from the irradiated solution by anion exchange
method. In the indirect technique, 1.2 g of NaBr pellet (10mmφ) with the natural isotope composition was irradiatedfor 5-10 minutes with proton beams (65 MeV) of 0.5-1μA.
The irradiated pellet was dissolved in 10 ml of H2O. Afterdissolving the pellet 5 ml of 10 % H2SO4 was added in thesolution. The resulting 76Kr was transported to the uppervial with H2 carrier gas and trapped in the 5 ml of H2O (Fig.
1). After the decay of 76Kr the generated 76Br was collected.
The 76Br produced by both methods was measured with thehigh-pure Ge detector in each solution.

The production of 76Br with proton induced reactions on
natural SeO2 and NaBr targets can be accomplished. These76
Br yields are summarized in Table 1. The production
yields were found to be 21-24 kBq/μA･min with SeO2
target and 126 MBq/μA･min with NaBr target (EOB). In
addition, the maximum production yield was calculatedusing the value of maximum beam current and irradiation
time at TIARA AVF cyclotron. It was estimated that theamount of 76Br was about 240 MBq in the use of SeO2
target, and was about 360 MBq in the use of NaBr. In thecomparison of production yields, an indirect method is moreadvantageous.
In a clinical application of 76Br, it is necessary to be
sufficient radioactivity for subsequent labeling. Further
research into the development of the production method
using enriched 76Se target is currently underway.

Fig. 1 Separation of Kr from NaBr. (a) Evacuation of the closed
system containing target + 0.2 g Zn powder. (b) Target dissolved inwater. (c) Hydrogen gas is evolved and carriers the Kr gases to thecollection vial containing 5 ml of ultra-pure water.

Table 1
Recovery yields of 76Br with SeO2 and NaBr targets and maximum activity using TIARA AVF cyclotron
Nucler reaction
76Se(p,n)76Br(direct method)
79Br(p,4n)76Kr-76Br(indirect method)

Beam energy
20 MeV
65 MeV

Target76Br yield

0.1% SeO2(kBq/μA･min)
21

10% SeO2

24

NaBr

126

－ 127 －

Irradiation
condition

76Br Activity

5μA×16 h

120 MBq
120MBq

3μA×16 h

360MBq360 MBq(calculated)

JAEA-Review 2007-060

3-62 Production of Radioisotopes for Nuclear Medicine Using
Ion-beam Technology and Its Utilization for Both
Therapeutic and Diagnostic Application in Cancer
a)

a)

b,d)

b,d)

d)

Y. Iida , H. Hanaoka , T. Katabuchi , S. Watanabe , N. S. Ishioka ,
d)
d)
c)
c)
c)
S. Watanabe S. Matsuhashi , T. Higuchi , N. Oriuchi and K. Endoa)b)

Department of Bioimaging Information Analysis, 21st Century COE Program and
Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate Schoold)of Medicine, Radiation-Applied Biology Division, QuBS, JAEAc)

PET is superior in quantitative measurement, so 18F-FDG-PET is most valuable tool for tumor diagnosis. Although several
positron emitters have been used for PET, their uses are limited for their short half-lives. Compared with these radionuclides,
64
Cu and 76Br have appropriate properties (76Br: T1/2 = 16.1hr, 64Cu: T1/2 = 12.7hr) and they may have great potentials for
PET utility. In this study, we synthesized monoclonal antibody (mAb) labeled with 64Cu or 76Br and evaluated their potential
for tumor diagnosis with PET. The results of tumor localization studies show that 64Cu or 76Br labeled mAb were highly
accumulated to tumor. From these data, the use of 64Cu and 76Br has great advantage for PET utility.

A.

B.

40

30

Blood
Liver
KidneyMuscle
Tumor

20

Blood
Liver
KidneyMuscleTumor

25
20%dose/g30%dose/g

15
10

10
5

50

40

30

20

10

50

40

30

20

10

0

0

0
0

PET（ポジトロン断層画像撮像法）はSPECT（シングルフォトン断層画像撮像法）、シンチカメラに比べ定量性、解像度の点で優れており、有用な画像診断法として注目されてきた。しかしながらPETに用いられる放射性核種（RI）はいずれも半減期が短く（18F：
110分、15O：2分、13N：10分、11C：20分）、その利用にはサイクロトロンの設置が必要になるなど費用がかかるため、普及が制限されていた。近年、がん診断における 18F標識グルコース（18F-FDG）の有用性が明らかになるとともに1)製薬企業による18F-FDGの供給が開始され、PETの普及は大きく進展したが、一方でやはり18F標識薬剤では安定したPET用製剤の供給に限界がある。そこで本研究では製薬企業からの供給が可能な程度の半減期（現在臨床で広く用いられている 123Iの半減期は約13時間）を有するPET用RIを利用し、がん診断を目的とした放射性薬剤の開発を行うことを計画した。
新しいPET診断用RIとして半減期：12.7時間の 64Cu
および半減期：16.1時間の76Brの製造を計画した。64Cu
は金属RIであることから化合物への導入にキレート結合部位を必要とするが、比較的安定な放射性薬剤を得ることが可能である。64Cuの製造は64Ni(p,n)64Cu反応に
よ り 行 っ た 。 得 ら れ た 64Cu を モ ノ ク ロ ー ナ ル 抗 体（NuB2）に標識し、マウスを用いてそのがん診断薬と し て の 有 効 性 を 評 価 し た 。 抗 体 と RI の 結 合 に は
1,4,8,11-tetraazacyclotetradecan-1,4,8,11-tetraacetic
acid(TETA)を用いた。
一方76Brは18Fや123Iと同じハロゲンであり、これまでに開発されたがん診断、脳機能診断などに有効な18Fあるいは 123I標識放射性薬剤をベースとした放射性薬剤の開発に適したRIであると考えられる。76Brの製造は
76
Se(p,n)76Brあるいは 79Br(p,4n)76Kr→76Brにより行った。
分離精製後、76BrをNuB2に直接標識し、64Cuと同様の方法により動物体内動態を評価した。
64
Cu-TETA-NuB2の標識率は約90%、精製後の放射化学的純度は99%以上であった。がんを移植したマウスに 64Cu-TETA-NuB2（約1µCi/匹）を投与したところ、Time after administration (hr)Fig.1 Biodistribution of (A) 67Cu- TETA-NuB2 and (B)76
Br-NuB2 in SCID mice bearing B-cell lymphoma
RPMI1788 tumor xenografts. For each time point, data
were acquired from five animals.
腫 瘍 へ の 高 い RI 集 積 を 認 め た 2) （ 投 与 ２ 日 後 で 約
13%dose/g 、 Fig.1A ） 。 一 方 76Br-NuB2 の 標 識 率 は 約10%と低く、精製後の放射化学的純度は約95 %であった。 64Cu同様、担がんマウスに 76Br-NuB2（1～4µCi/匹 ） を 投 与 し 、 そ の 体 内 動 態 を 調 べ た 結 果 、 76BrNuB2も腫瘍へ高く移行することを認めた3)（投与２日後で約10%dose/g、Fig.1B）。
以上の結果より、新規PET用RIを用いたがん診断薬剤の有効性が示された。
References
1) Endo K, et al., Int. J. Clin. Oncol. 11, 286 (2006).
2) IIDA Y., et al., Proc. Mol. Imaging 5, 361(2006), The
Big Island of Hawaii, USA.
3) IIDA Y., et al., Proc. World Journal of Nuclear Medicine
5, suppl1 S189(2006), Seoul, Korea.

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JAEA-Review 2007-060

3-63 Incident Energy Effect of the Production Yield ofEndohedral 133Xe-Fullerene by Ion Implantation
S. Watanabe, N. S. Ishioka and S. Matsuhashi
Radiation-Applied Biology Division, QuBS, JAEA

0.8

Radioactivity:133Xe

0.6

UV absorption: C60

between the C60 and 133Xe peaks corroborates the formationof 133Xe@C60. HPLC data obtained from the other samples
also corroborate the formation of 133Xe@C60. In order toevaluate the efficiency of the formation of 133Xe@C60, theyield of 133Xe@C60 was defined as a percentage of theradioactivity of 133Xe@C60 to that of 133Xe implanted into
the target. The radioactivity of 133Xe@C60 was obtained
from the sum of the 133Xe radioactivities in the fractions
from 3 to 10 min. The yields of 133Xe@C60, each of which isderived from one experiment, were plotted as a function of133
Xe dose in Fig. 2. The solid and broken straight lines inthose figures, which were fitted by the method ofleast-squares
onlog-logscales,arey=(10.18±0.09)-(0.842±0.007)xand
y=(9.6±0.8)-(0.80±0.06)x on 15 and 30 keV, respectively.
For both dose studied, the yields of 133Xe@C60 were foundto decrease with increasing dose. Because an increase of thedose leads to an increase of the number of damaged
fullerene molecules as reported by Kastner et al.2) from their
Raman spectra measurements of fullerene targets
bombarded with energetic-ions, those dose dependences ofthe production yields can be ascribed to amorphization of133
Xe@C60.
From comparison between both lines one can note thatthe yield of 15 keV is about 25% larger than that of 30 keV
for the same dose in the rage of 1x1012 to 1x1014 cm-2.
Those energy dependences of the production yields can bealso ascribed to the amorphization of 133Xe@C60. The yieldsof the 133Xe@C60 should be more increased by decreasing
incident energy.
References
1) S. Watanabe et al., J. Radioanal. Nucl. Chem., 255(2003) 495.
2) J. Kastner et al., Appl. Phys. Lett. 65 (1994) 54.

Production yield (%)

Intensity (arb. units)

Endohedral fullerenes encapsulating a radioisotope within
a fullerene cage have a possibility of being new
radiopharmaceuticals. We have prepared endohedral
133
Xe-fullerenes by ion implantation1). Xenon-133 (T1/2 =5.243 d) would be useful for cancer therapy because it emits
0.346-MeV β– rays (maximum range in water: 1.0 mm)
followed by 81-keV γ rays and conversion electrons
associated with the γ transition. However, we could not
obtain efficient production of endohedral 133Xe-fullerene.
To achieve more efficient production, conditions of the ion
implantation, especially incident energy, has to be studied.
In the present paper, we describe incident energy effect on
the production yield of endohedral 133Xe-fullerene.
Fullerene targets for ion implantation were made byvacuum evaporation of C60 on Ni foils. Implantation of
133
Xe+ ions into the targets was carried out with an isotope
separator at acceleration energies of 30 keV. For retardationof incident energy, the high voltage of 15kV was supplied
from a retardation power supply to the fullerene targets:incident energy became 15 keV. Doses were in the rage of
1x1012 to 1x1014 cm-2. After ion implantation, the fullerenepart on the target was dissolved in o-dichlorobenzene. The
solution was filtered through a membrane filter to remove
insoluble materials. The filtrate was analyzed by highperformance liquid chromatography (HPLC) with a
Cosmosil Buckyprep column. Elution was done witho-dichlorobenzene at a flow rate of 1 ml/min. The
concentration of fullerene in the effluent was continuously
monitored by a UV detector. The effluent after UVmeasurement was collected in glass vials each for 1 min
until 20 min and the 133Xe radioactivity in each vial wasmeasured by γ-ray spectrometry.
Figure 1 shows elution curves of 133Xe and C60 obtained
from the sample bombarded with 133Xe ions of 15 keV at adose of 2.0x1012 cm-2. The strong correlation observed

0.4
0.2
0.0

0

5
10
15
Retention time / min

100

10-1
15 keV
30 keV
10-2 1210

20

Fig.1 HPLC elution curves of 133Xe and C60.

1013
Dose / cm-2

1014

Fig.2 The yield of 133Xe@C60 as a function of 133Xe
dose.

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JAEA-Review 2007-060

3-64 Analysis of Elements in Tumors and Normal Tissues
following Irradiation by Micro-PIXE
a,c,d)

a,c)

b,c)

d)

d)

M. Hasegawa, H. Sakurai , S. Ishiuchi , T. Tamamoto , I. Asakawa , M. Shin
c,e)
e)
c,e)
c,e)
a,c)
and T. Nakano
M. Oikawa , T. Satoh , T. Kamiya , K. Arakawa
a)

b)

a,c)

,

c)

Departments of Radiation Oncology and Neurosurgery, and 21st Century COE Program,d)Gunma University Graduate School of Medicine, Department of Radiation Oncology, Narae)
Medical University, and Department of Advanced Radiation Technology, TARRI, JAEA
The distribution of elements at the cellular level can beimaged by an in-air micro-particle-induced X-ray emission(micro-PIXE), but its application at the tissue level has beenvery limited. We compared the distribution of elements intumors and normal tissues examined by the micro-PIXE withlight-microscopic findings 1). Furthermore, we analyzed thechanges in the distribution of elements caused by cell death
before and after irradiation.
Human ependymoblastoma, glioblastoma, and small cell lungcancer (SCLC) subcutaneously transplanted into male nude
mice and normal organs (spleens, livers, kidneys, and testes) ofmice were examined. X-ray irradiation (10 or 20 Gy) was
administered, and the tumors or normal tissues were excised 3,
4.5, 6, 24, and 72 hours after irradiation. Frozen sections
produced with a thickness of 5 and 10 micrometers were fixedby rapid drying and examined using an in-air micro-PIXE.
After the examination, the samples were stained byhematoxylin-eosin, and observed by light microscopy tocompare the distribution of elements and histological findings.
In the control (non-irradiation) groups, phosphorus (P),potassium (K), chlorine (Cl), and sulfur (S) were observed in theregions, corresponding to viable cells of the 3 tumors andnormal tissues, and these elements seemed to be distributed in
the nuclei and cytoplasm. In homogeneous areas of cells, theseelements were homogeneously distributed, agreeing well withthe morphological findings by light microscopy. But, theresolution of light microscopy was clearly higher than that of the
micro-PIXE method. There were no significant correlations
between the distribution of calcium (Ca), silicon (Si), or iron(Fe) and morphological findings. In the control groups ofglioblastoma and SCLC, small necrotic areas were observed,
and P, K, Cl, and S were significantly decreased in these lesions.
In the irradiation groups, a high incidence of TUNEL-positive
apoptosis was detected in the ependymoblastoma and spleen 3-6
hours after 10 or 20 Gy irradiation by light microscopy. The
incidence peaked 6 hours after, and decreased 24 hours after
irradiation. In all ependymoblastoma and spleen samples witha thickness of 5, 10, or 20 micrometers, no significant
differences between the irradiation and control groups weredetected by the micro-PIXE, and the findings were almost thesame as those in the control group or slightly inhomogenous insome samples (Fig.1).
In the irradiation groups ofglioblastoma and SCLC, small necrotic areas were detected at
all excision times, and marked decreases in P, K, Cl, and S wereobserved in the regions, corresponding to the necrosed lesions
and tissue defects. But, there was no significant difference inthis change observed in the necrosed lesions between theirradiation and non-irradiation groups. No significant changes of
elements were observed in the kidneys, livers and testes by the
micro-PIXE, though a few apoptotic spermatogonia were foundin the testes. There were no significant changes in the
distribution of Ca, Si, and Fe in all tumors and normal tissues.
The light-microscopic morphology of the 3 different types oftumors and 4 organs examined in this study markedly differed,but examination by the micro-PIXE demonstrated almost no
differences among the tumors and organs if they do not havenecrotic areas. The resolution of light microscopy was clearlyhigher than that of the micro-PIXE.
In this study, we evaluated the applicability of an in-air
micro-PIXE method to analyze of the distribution of elements atthe tumor and normal tissue levels, and found that necrotic
lesions could be imaged, suggesting the usefulness of thismethod in biological and medical fields. However, since theresolution of this method is much lower than that of lightmicroscopy and apoptotic cell death was not detected, its
improvement is required for evaluating the involvement ofelements in microscopic changes.

P

K

S

Fig.1 Spleen; 6hours after 20Gy irradiation.
Reference1)Hasegawa M, Sakurai H, Ishiuchi S, Tamamoto T,Asakawa I,
Shin M, Oikawa M, Satoh T, Kamiya T, Arakawa K,
Nakano T. Analysis of radiation-induced cell death in vivo
by micro particle-induced X-ray emission (micro PIXE).
JAEA-Review 2006-42, 168 (2007).

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JAEA-Review 2007-060

3-65 Investigation of Cisplatin Sensitivity in Esophageal
Squamous Cancer Cell Lines and the Localization of
Pt Using In-air Micro-PIXE
a)

a)

a)

a)

b)

b)

N. Tanaka , H. Kimura , T. Asao , H. Kuwano , T. Sakai , M. Oikawa , T. Satohb)b)
and T. Kamiyaa)

The 21st Century program, Graduate School of Medicine, Gunma Universityb)
Department of Advanced Radiation Technology, TARRI, JAEA

The purpose of this study was to elucidate the involvement of CDDP(cis-diammine dichloroplatium) in
ESCC(esophageal squamous cell carcinoma) using in air-micro PIXE (Particle Induced X-ray Emission). Two human
ESCC cell lines–TE-2 and TE-13–were examined for their response to CDDP. TE-2 cells were more highly sensitive to
CDDP than TE-13 cells in MTT assay. Dynamic state of element and intracellular metabolism were measured in CDDP
treated cancer cells using air PIXE. Using air PIXE, we observed distribution of P and K were localized at cytoplasm,
and Br was localized at nuclear site. Air PIXE may be one of the new methods to measure CDDP combined withexisting methods. Intracellular concentration of Pt was measured using air PIXE, unfortunately we cannot confirm thedifference of distribution of intranuclear Pt in two cells at this moment. Air PIXE may have role in application to predict
CDDP sensitivity in cancer cells. Our results using air PIXE has limitation, since it only can be presented by theimaging semi quantitative data. Future study will be needed to establish a new method for precise quantitative data.
プルにて、比較的短時間の照射でPt分布の安定した
近年 、 様 々 な 癌に お い て 数 多く の 遺 伝 子 の研 究
検 出が 可 能 で あ った 。 ま た 、 シス プ ラ チ ン は核 内
が 行わ れ て い る が、 い ま だ に 不明 な 点 が 多 く、 特に作用 する こ とに着 目し 、 細胞培 養の 段 階でBrdUに 元素 動 態 や 分 布な ど の レ ベ ルに お い て は 殆ど 知られて いな い 。そこ で我 々 は、大 気マ イ クロPIXE
を 用い て 、 食 道 扁平 上 皮 癌 に おけ る シ ス プ ラチ ン
(Pt)の取り込みの検討を行った。食道癌は独特な生物学的特徴を有する癌である 1) 。化学放射線療法が効 果 的 な 癌 の 一 つ で あ り 、 そ の responder と nonBr
P
Br
P
responderを 選 別 す る こ と は 、 個 別 化 治 療 に お い て重 要な 課 題 に な って い る 。 我 々は 分 子 生 物 学的 ア
TE-2
プ ロー チ に よ る 食道 癌 患 者 に おけ る 化 学 放 射線 療
2)法の感受性評価法を検討し報告している 。我々は既存の 感受 性 評価法 にPIXEの技術 を融 合 させる こ
Fig. 1. Cell lines (TE-2) was cultured in mediumと によ り 、 さ ら に精 度 の 高 い 感受 性 評 価 法 を開 発
including BrdU for 24 hours. The cellular configuration
で きな い か と 考 えた 。 我 々 は これ ま で の 検 討で 、
was identified by phosphorus (P). The nuclear
シ ス プ ラ チ ン 処 理 し た 食 道 癌 細 胞 株 を 試 料とし て、 localization in cell was identified by bromine (Br). The
PIXEを用い た 測定に より 、 細胞内 プラ チ ナ元素 のT/N ratio shows a marked tendency to high.
検 出が 可 能 で あ るこ と を 見 出 した 。 続 い て 、感 受
を 用い る こ と で 、細 胞 内 に お ける 核 の 局 在 を確 認
性 の相 違 に よ る シス プ ラ チ ン 投与 後 の 細 胞 内元 素した。PIXEの実験では、カリウム(K)とリン(P)の分
動 態を 比 較 す る ため 、 基 礎 実 験と し て シ ス プラ チ
布より細胞質の形態の確認を行った。Fig. 1に細胞ン 感受 性 試 験 食 道癌 細 胞 株 を 用い て シ ス プ ラチ ンの形態を表す Pと核の局在を表す Brの 2次元分布画
感 受 性 試 験 (MTT assay)を行 い 、 高 感 受 性 株 (TE-2)
像と、 それ を 合成し たカ ラ ー画像 を示 す 。PIXE分と低感 受性 株(TE-13)を見出 した。 この 差 異につ き析の結果、高感受性株(TE-2)において細胞内のPtカ
細胞周期およびアポトーシスの面からも、FACSやウントが2488、核内が894であった。現在は、高感DNA fragmentation assayを行い確認している。様々
受性株のみ核内のPt分布の半定量化を行ったところな シス プ ラ チ ン 投与 濃 度 と 時 間を 組 み 合 わ せ、 試である が、 今 後はシ スプ ラ チン低 感受 性 株(TE-13)
料作成 を行 い 、PIXEを用い たシス プラ チ ン感受 性に おい て も 同 様 の検 討 を 行 い 、両 者 の 比 較 検討 を
評 価に お け る 試 料の 最 適 化 を 目指 し た 。 シ スプ ラ
行っていく予定である。
チンを細胞内のPt分布として評価するには、感受性
評 価 に 用 い ら れ る IC50よ り 、 か な り 高 濃 度 で の 投
References
与 が必 要 で あ っ た。 た だ し 、 この 濃 度 で の 長時 間
1) Kuwano H., et al., Ann Thorac Cardiovasc Surg.
投与ではほとんど全ての細胞がviabilityを失うため、2003 Feb; 9(1): 6-13.
高 濃度 短 時 間 投 与、 具 体 的 に は、 マ イ ラ ー 膜上 に
2) Sohda M., et al., Int J Cancer, 2004. 110(6): 838-44.
細 胞 を 生 着 さ せ 、 2.0 mM の シ ス プ ラ チ ン 含 有 メ
ディウムで1時間培養し、洗浄後凍結乾燥したサン－ 131 －

JAEA-Review 2007-060

3-66 Direct Visualization and Quantification of Cis-platinum
in a Human Lung Cancer Cell Using Micro-PIXE
Analysis
a)

a)

b)

c)

c)

H. Sakurai , M. Okamoto , M. Hasegawa , T. Satoh c), M. Oikawa , T. Kamiya ,c)a)K. Arakawa and T. Nakano
a)Department of Radiation Oncology, Gunma University Graduate School of Medicine,c)
Department of Radiology, Nara Medical University, Department of Advanced Radiation
Technology, TARRI, JAEAb)

We established an imaging method of intracellular CDDP, and also established the method of quantification of
intracellular CDDP in a human lung cancer cell line using air micro-PIXE. For the purpose of nuclear labeling, the cells wereincubated with 10 μM BrdU. After the pulse labeling of BrdU, the cells were exposed to CDDP at a concentration of 1 mM
for 30 min to 24 hr. Analyses were performed with an in-air micro-PIXE system at the division of Takasaki ion accelerator
for advanced radiation (TIARA). For 24 hr exposure of CDDP, there was unclear Pt signal detected at dose of 1-100 μM.
However, significant Pt signals were seen dose at 1 mM. The Pt image quality by micro-PIXE was considered adequate if
both the nucleus and cytoplasm could be visualized well enough to allow performance of the procedure. The stronger signals
were detected in the intracellular nucleus rather than in the cytoplasm. For time course study, longer exposure time of CDDP
shows more uptake of the drug in the cells. The elemental analysis using air micro-PIXE can be applied for biomedical
samples. Intracellular distribution of CDDP can be visualized with very fine resolution, and individual intracellularconcentration of CDDP can be measured using our system.
胞に取り込まれたPtが検出可能であった．シスプラチ
シスプラチンは現在，頭頸部腫瘍から肺癌，消化器
ン接触時間の延長とともに，細胞内Ptおよび核内Ptの癌，婦人科癌にまで幅広い領域でkey drugとなっていカウントの増加が観察された（Fig２）が，生物実験る．また，シスプラチンはこれらの腫瘍に対し，放射に応用可能なPt濃度での検出は困難であった．
線治療と併用して，有効な増感効果をもたらすとされている．しかし，臨床ではシスプラチンによる治療効大気マイクロPIXEによるPtの細胞内可視化，定量化
果には，患者ごとに明らかな感受性の差がある．もし， が可能であった．生物試料に応用可能であるが，検出個々の癌細胞の取り込んだシスプラチンが画像化，定感度をあげる工夫が必要と考えられた．
量化できれば，シスプラチン感受性やシスプラチン耐
100Count/nC性機構の解析のために，重要な情報をもたらすと考え
ら れ る ． 一 方 ， 大 気 マ イ ク ロ PIXE （ Particle
10
Induced Ｘ-Ray Emission）は数MeVに加速したプロトンを試料に照射し，放出される特性X線を検出する
1
ことにより，試料中に含まれる多くの元素を1 μmの分解能で解析できる装置である．個々の癌細胞の取り1
込んだシスプラチンを画像化，定量化できれば，シス
プラチン感受性やシスプラチン耐性機構の解析において，重要な情報をもたらすと考えられる．
0.
1
1
10
100
大気マイクロPIXEによるPtの定量性を確認するため
CDDP concentrate (x10-18 mol/μm2)に，標準試料（Pt濃度を変化させた寒天を20 μmに薄Fig.1. Three standard samples with different CDDP
切し凍結乾燥したもの）を作成し，測定を行った．細concentration was analyzed by in-air micro-PIXE
胞はヒト肺腺癌細胞であるA549を用いて，10 μM の (Pt count / nC)
BrdUでパルスラベルした対数増殖期の細胞を5 μm厚の80
マイラーフィルム上で培養し，生着したことを確認し60た後，1 mMのシスプラチンを接触させた．接触時間は30分から24時間とした．薬剤に接触後，THAMバッ
40
ファーで６回洗浄した後，急速凍結乾燥した．解析はIntracellular
日本原子力研究開発機構高崎量子応用研究所の大気マ
20
イクロPIXE測定装置を用いた．
nuclear
標準試料を用いた解析では，試料内のシスプラチン
0
0
3
6
9
12
1
18
2
24 (hours)
濃度と測定されたPtの間に直線性が明らかであった（Fig.１）．培養細胞試料では，P，K，Clなどの細胞
Fig.2. Intracellular and nuclear platinum count / nCの局在を示す元素，BrdUでラベルした核内Brおよび細according to CDDP exposure time

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JAEA-Review 2007-060

3-67 Analysis of Trace Metal of HCV Replicon by
In-air Micro- PIXE and ICP-MS
K. Yuasa, H. Takagi, E. Saito, D. Takizawa, T. Ichikawa, S. Kakizaki, K. Sato,and M. Mori
Department of Medicine and Molecular Science, Gunma University Graduate School of
Medicine
We had reported that zinc was a negative regulator of HCV replication. The distribution of trace metal in HCV
replicon (HCV-O) using in-air micro-PIXE and ICP-MS was analyzed. In-air micro-PIXE revealed more zinc in
nucleus than in cytoplasm and no significant difference was observed in HCV-O and control (Huh7). On the contrary,
ICP-MS proved that zinc bound-metallothionein was higher in HCV-O than in be needed to elucidate thisdiscrepancy.
1. はじめに
我々は微量金属の亜鉛が C 型肝炎ウイルス(HCV)に対して一定の抗ウイルス効果を有する事を報告してきた 1,2,) .しかし、亜鉛の HCV に対する作用は十分解明されてはいない。今回我々は in vitro HCV
産生細胞である HCV replicon を用い、micro PIXE
及びその他の定量系により HCV と微量金属、特に亜鉛の関係を調べた。
2. 実験方法
HCV replicon(HCV-O)は 岡 山 大学 加 藤 宣 之 教授 より供与された。本細胞は人肝癌細胞株 Huh7 に fulllength の HCV を感染させて樹立された。Huh7 をコントロールとして、無刺激、Zn、interferon (IFN)、
両者の併用による影響をみた。1) micro PIXE を用
い細胞内微量金属を測定した。2) ICP-MS により細胞内 Zn、Cu、メタロチオネインの濃度を測定した。3) メタロチオネインは免疫染色、CdHem assay
によっても測定した。
3. 結果
1) micro PIXE によって得た P と Br の分布から、細胞、核の contour を同定し得た。さらにそれに基づき細胞の Zn の分布を HCV-O と Huh7 で比較したところ差は無く、Zn、IFN, 両者の併用でも著明な差は見られなかった（Fig 1）。2) ICP-MS による測定では、無刺激状態では HCV-O は Huh7 に比しZn は少ないが、Zn 刺激によって Huh7 より高まり、
それは metallothionein (MT)結合型であった（datanot shown）。3) MT の染色では、いずれも亜鉛添加に よ り コ ン ト ロ ー ル に 比 し MT は 増 加 し た が、
HCV-O でより強く増加した（Fig 2）。IFN と亜鉛併用でその傾向はより強くなった。
4. 考察
micro PIXE に よ る細 胞 個 々 の 微量 元 素 の 分布を
HCV-O にお いて 測定 し た のは 今回 が 始 めてであり、Zn の核への局在は確認された。しかし、Huh7との違い、刺激による変化を見出すことはできなかった。微量定量系である ICP-MS では Zn 刺激に
より HCV-O は MT 結合型の Zn をより多く、細胞内に取り込むことが判明し、MT 染色でも確認された。定量的には HCV は明らかに Zn の動態に影響を与えているが、micro PIXE ではその違いを捉え ら れ な い と い う 結 果 で あ っ た 。 今 後 は micro
PIXE での定量の可能性と、Zn 変化のメカニズムについて検討したい。
Huh7
P

Br/P

HCV-O
Zn/P

Zn/Br

P

Br/P

Zn/P

Zn/Br

Drug(-)

Zn
IFN
IFN
+Zn

Fig 1．P, Br and Zn distribution map of Huh7 and
HCV-O. Both cells were stimulated with Zn, IFN andboth. P map represents whole cell figure and Br does
nucleus as a background of Zn map. Zn and Br exist in
the same area.

Fig 2. Huh7 and HCV-O are immunostained formetallothionein. Each cell was stimulated with Zn, and
HCV-O showed higher expression of metallothionein
than Huh7.

References1).Takagi H, et al. J Viral Hepatitis.
8:367-371(2001)
2).Yuasa K, et al. Liver Int. 26:1111-8, (2006)－ 133 －

JAEA-Review 2007-060

3-68 Improved Radiosensitive Liquid-core Microcapsules forTargeting of Chemotherapeutic Agents
a)

a)

b)

b)

b)

S. Harada , S. Ehara , K. Ishii , H. Yamazaki , S. Matsuyamac)c)c)T. Satoh , M. Oikawa , T. Kamiya , K. Arakawa c) and K. Sera d)a)

Department of Radiology, Iwate Medical University
Department of Quantum Science and Energy Engineering, Tohoku Universityc)
Department of Advanced Radiation Technology, TARRI, JAEAd)Cyclotron Center of Iwate Medical Universityb)

We have reported that microcapsules consisting of alginate
and hyaluronic acid can decomposed by irradiation, andreleases their core contents. These microcapsules havebeen generated by spraying a mixture of alginate andhyaluronic acid into CaCl2 solution for more than 30 min.
However, the use of Ca results in the hardening of thealginate, and the long polymerization time of more than 30
min results in the formation of microcapsules with thickouter shells. These factors prevent the efficient release ofcore contents from microcapsules1).
During microcapsule development, we observed thatyttrium (Y) prevents the regular polymerization of alginate
by calcium (Ca), thereby allowing easy rupture of the
microcapsules. Moreover, sonication of a mixture ofalginate and hyaluronic acid results in shorter
polymerization time that in turn results in the formation of
microcapsules with thin outer shells2). In this study, theeffect of Ca-Y polymerization and sonication of materials
were tested, using micro-PIXE camera.
A 0.2% (w/v) alginate solution and 0.1% (w/v) hyaluronic
acid were mixed in an agar pestle; these percentages were
determined in our previous experiment1, 2. To this mixture,
0.2 mmol carboplatin (a platinum (Pt)-containing anticancerdrug) was added. A droplet of this mixture was sonicatedusing an ultrasound disintegrator and atomized to yield a
4.34% solution of CaCl2 that was supplemented with Y atconcentrations ranging from 0% to 0.01%. Resulting
microcapsules was irradiated with single doses of 0.5, 1.0,
1.5, or 2 Gy 60Co γ-radiation. Then a frequency of
microcapsules’ rupturing were tested by micro PIXE

camera.
The distribution of the microcapsular core contents(carboplatin) was imaged using a micro PIXE camera that
detected platinum (Pt) signals (Fig. 1 a–h). The contoursof the microcapsules were identified by detecting the
distribution of Ca and ion beam-induced charge (IBIC) (Fig.
1(b), (d), (f), and (h)).
Prior to irradiation, themicrocapsule contours were clearly detected, and Pt wasobserved to be distributed within the capsules (Fig. 1(a), (b),and (d)). After irradiation, microcapsules with unclear Ca
or Y distribution and with heterogeneous distribution of Pt(Fig. 1 (a)–(c) and (e)–(g)) were observed. We determinedthat these types of microcapsules had released their corecontents upon irradiation. The frequency of microcapsules’
rupturing were shown Fig.-2. The increment in thefrequencies of microcapsule decomposition was dependent
on the final concentrations of the added Y (Fig. 2). Whenthe concentration of the added Y exceeded 3.0 × 10–3%, thefrequency of decomposition increased significantly (Fig.2).
Significant increases in these frequencies were also
observed when the radiation dose exceeded 1.0 Gy (Fig. 2).
The maximum decomposition frequency was observed
when the final concentration of the added Y was 5.5 ×
10–3% with 2.0-Gy irradiation. 2.0-Gy is the dose that isused in the conventional fractionated radiotherapy.
Therefore, our microcapsules have a great possibility to be
used in combination with clinical radiotherapy.
References
1) S. Harada Nucl. Instrum. Methods. B In press.
2) S. Harada IJ PIXE In press.

100

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Yttrium(×10Finalconcentration
concentration ofofadded
Yttrium(x 10-3%)

Fig.-1

Fig.-2－ 134 －

JAEA-Review 2007-060

3-69 Fluorine Uptake into Enamel around
Fluoride-containing Materials during pH-cycling
a)

a)

b)

b)

b)

c)

H. Komatsu , Y. Matsuda , H. Yamamoto , Y. Iwami , S. Ebisu , M. Nomachi ,
c)
d)
e)
e)
e)
Y. Sugaya , K. Yasuda , T. Satoh , M. Oikawa and T. Kamiyaa)Department of Oral Health Science, Hokkaido University Graduate School of Dentalb)c)Medicine, Osaka University Graduate School of Dentistry, Osaka University Graduated)e)School of Science, The Wakasa Wan Energy Research Center, Department of Advanced
Radiation Technology, TARRI, JAEA
Introduction
It is well established that the fluorine (F) is a possible
agent for caries prevention. Also, the fluoride that containedsome restorative material was demonstrated as a great
benefit for preventing dental caries. The purpose of thisstudy was to determine fluorine (F) uptake into enamelaround fluoride-containing materials during pH-cycling1)
using proton induced gamma-ray emission or PIGE
technique2).
Material and Methods
Class I cavities in the buccal surfaces of 6 extracted
human teeth were drilled and filled with fluoride-containing
materials; “Fuji IX (GC)” (FN) and “UniFil flow (GC)”with“MEGA bond
(KURARAY)”
(UF),
and
nonfluoride-containing material; “SOLARE (GC)” (SO).
Four 300-µm sections through the material were obtained
from each tooth. All specimens were polished to a thicknessof 120 µm. All tooth surfaces, except outer surface ofenamel, were coated with a wax. In order to simulate dailyacid challenges occurring in the oral cavity, the pH-cycling(pH 7.0-pH 4.5) was carried out for 0, 1, 3 and 5 weeks,
separately1). After pH-cycling, F distribution of the outer
lesion in each specimen was evaluated using PIGE
technique2). The amount of F in the outer 125 µm of thelesion was calculated. Two-way ANOVA and Bonferroni
test were used for the analysis (p<.05).
Results
F distribution of the specimens clearly showed the F
uptake from FN into only enamel adjacent to the material,
while the F uptake from UF and SO were not detected. The
enamel adjacent to only FN remained the area as caries
inhibition zone in wall lesion. For FN, the amount of F
uptake into the outer lesion increased during pH-cycling(Fig. 1). The amount of F uptake in 5-week pH-cycling hadsignificantly higher value comparing to those in 1- and3-week pH-cycling. For UF and SO, there were no
significant differences among the duration of pH-cycling(Fig. 2 and 3).
Discussion
For fluoride-containing UF, the F uptake into cavity wall
was not detected. This indicated the bonding layer between
the tooth and fluoride-containing material interfered with
the F absorption into the tooth. Therefore, there was not thearea as caries inhibition zone in wall lesion. It was

confirmed that the amount of F uptake from FN increased
during pH cycling. In a pH of 5.5-4.5, hydroxyapatite
dissolves and, by supplying fluorine, precipitation offluorapatite (FA) occurs because of the continuing
supersaturation of FA. This suggests that FN operated as aresource for supplying fluorine when the pH was in the low
range.

Fig. 1 Fluorine uptake from FN into the outer lesion
during pH-cycling.

Fig. 2 Fluorine uptake from UF into the outer lesion
during pH-cycling.

Fig. 3 Fluorine uptake from SO into the outer lesion
during pH-cycling.
Conclusion
Among fluoride-containing materials, there existed somedifferences in the F uptake with increasing pH cycling.
References
1) Y. Matsuda et al., Dent. Mater. J. 24 (2006) 280.
2) H.Yamamoto et al., Nucl. Instr. Meth. B 210 (2003) 388.

－ 135 －

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JAEA-Review 2007-060

4-01 SiC-based Membrane for Gas Separation
Synthesized by EB Curing of Precursor Polymers
R.A. Wach, S. Yamamoto, M. Sugimoto and M. Yoshikawa
Environment and Industrial Materials Research Division, QuBS, JAEA
Introduction

SiC thin layer ceramics are expected to surpass theperformance of polymeric, silica and carbon membranes.
Beside superior mechanical behavior, they exhibit highoxidation resistance. Production of SiC coatings usually
includes techniques where the substrate component is an
inorganic SiC. However employment of organometallic
polymer precursor, such as polycarbosilane (PCS) depositedfrom solution followed by pyrolysis is a simple andconvenient method for SiC production. Recently we applied
PCS and/or polyvinylsilane (PVS) derived SiC-basecoatings on γ-Al2O3 substrate, as membranes for gas
separation. Nevertheless, thermal stability of the substrate
limits pyrolysis temperature to relatively low, 850oC1).
Present report describes combination of two deposition
methods, i.e. pulsed laser deposition (PLD) and polymer
derived coating.

2.

References
1) R.A. Wach, M. Sugimoto, M. Yoshikawa, J. Am. Ceram.
Soc. 90, 275 (2007).

Experimental Procedure

α-Al2O3 was used as a substrate. Initially, PLD system
was used with a SiC target at argon atmosphere and 500oC.
Subsequently, a blend of PCS (Mn 2600) and PVS (Mw
2800, Mn 960) in cyclohexane solution was spin coated onto
PLD surface. Samples were cured (or not) by EB, typicallyto dose of 1.2 MGy at a dose rate of 1.2 kGy/s, under dry air
atmosphere. In order to transform the polymeric coating into
an inorganic SiC-based one, samples were pyrolyzed in Ar
atmosphere up to 850 oC using controlled heating ramp.
Nitrogen and hydrogen gas permeation tests were conductedwith samples of effective permeation area of 1.0 cm2 by avacuum method.

3.

Accordingly, H2/N2 perm- selectivity was usually better thanthat characteristic for Knudsen diffusion. As an example,
H2/N2 separation is presented in Fig.2. It was found nearly
independent of PLD time, but strongly dependent on thepolymer derived film. Here, one and two coating, irradiation,
firing sequence is shown. Separation ratio is better, about 20,
for twice coated substrate. So far, this separation ratio issmaller than that measured for membranes fabricated byfour times polymer deposition1). Therefore the combination
technique presented here should be further developed.

Fig.1. Surface of (a) PLD and (b) Polymer derived SiC.

Results and Discussion

While considering fabrication methods of membranes forselective gas permeation, controlling of pore diameter is the
crucial issue. Surface of PLD and PCS/PVS (80/20wt%)
derived SiC deposited on alumina substrate is presented inFig. 1. A rough surface resulted from PLD deposition (5h)does not provide satisfying membrane parameters: N2
permeance was measured as 2.5x10-7 mol⋅sec-1m-2pa-1 andH2/N2 separation of 3.7 (Knudsen diffusion).
However, it provides proper support for polymer
deposition. γ-alumina substrates with PLD originated SiC
coated by preceramic polymer after pyrolysis shows
relatively smooth surface. Thus we expect that such
two-step technology of membrane preparation will bebeneficial for its performance. Permeance of hydrogen andnitrogen was measured, and it was in the range 10-10 - 10-8mol⋅sec-1⋅m-2⋅pa-1 depending on fabrication parameters.

H2/N2 selectivity

1.

10

3h + 1x polymer
2h + 2x polymer
1h + 2x polymer
Li et al.

1

0

50

100

150

200

250

300

Temperaure (℃)
Fig.2. Perm-selectivity of N2 and H2. PLD followed bypolymer deposition: PCS 80/20 PVS, 3% cyclohexane,
spin coated at 1000rpm, irradiated at 1.2 MGy, fired at
850oC in Ar.

－ 143 －

JAEA-Review 2007-060

4-02 Effect of Ion Beam Irradiation on SiC Thin
Film for Gas Separation
M. Sugimoto, R. A. Wach, S. Yamamoto, A. Inoue and M. Yoshikawa
Environment and Industrial Materials Research Division, QuBS, JAEA

2.

Experimental Procedure

The polycarbosilane (PCS) concentration of 2.5% in
cyclohexane solution was spin coated at 1000 rpm onto porousalumina substrates, and the coated substrates were cured bythermal oxidation at 453K, and then fired in Ar at 1023K totransform the polymeric film into an inorganic SiC
ceramic-based one. The SiC thin film with 0.5μm thickness
was synthesized by repeating these process five times.
Subsequently, the hydrogen and nitrogen permeation of thesamples at 373 and 473K were measured by differential pressure
method. The samples exhibiting the gas separation function by
the molecular sieving mechanism were irradiated with several
kinds of ions with energies enough to pass through the SiC thinfilm. After irradiation, nitrogen and hydrogen gas permeation
tests were conducted with samples exhibiting effective
permeation. Moreover, the SiC thin films of 0.2 and 0.4 μm inthickness were formed on the silicon substrate using similar
process, and the change in the film thickness by the ion beamirradiation was examined.

3.

fired at low temperatures compared with ceramic structural
materials such as SiC fiber, and thus it has shrunk easily by ion
beam irradiation as well as shrinkage of the amorphous silica
film 2). The size of the nano-hole in which only hydrogen
penetrates by the molecular sieve mechanism is about 0.3nm,
and the number of the holes depends on the density of the SiC
films. Therefore, the number of holes decreases by shrinkage,leading to a decrease in the amount of the gas permeation.
In the case of 0.5 MeV Pt irradiation, the projected range wasestimated to be 0.14 μm below the SiC film thickness, andtherefore the shrunk part was less than those of the other samples
irradiated by high energy ions. However, the Pr irradiated film
showed the smallest values of hydrogen and nitrogen
permeation. According to the results of Rutherford
Backscattering Spectrometry, the thin layer containing Pt wasformed in the SiC film. It suggests that the formation of suchthin layer reduces the number of nano holes, leading to thedecrease of hydrogen and nitrogen permeation. Further
investigations are necessary to clarify the mechanisms behind Pt
irradiation.
References
1) R.A. Wach, et.al. J. Am. Ceram. Soc. 90, 275 (2007).
2) E. Snoeks, et.al. Appl. Phys. Lett., 65, 19, 7 (1994).
1.4
1.2

H2

N2

1
Pa/Pb

Introduction

SiC thin film synthesized from Si-based polymer as a ceramic
precursor by firing has an excellent thermal and corrosion
resistance, and the structure is amorphous with nano-hole which
has gas permeability 1). Therefore, the SiC thin film is expected
as a hydrogen separation filter that can be used in the severe
environment. However, the improvement of the amount of thehydrogen penetration and the separation ratio is required. In
this research, the possibility of controlling the gas penetration of
the SiC thin film was examined by the methods of ion
implantation to form the hydrogen catalyst layer in the SiC film
and of making nano-hole structure by passing high energy ions.

0.8
0.6
0.4
0.2
0

Results and Discussion

Pt 0.5M eV

H 1M eVHe 3M eVC 6M eVNi 388M eV Kr 520M eV

Pa: Permeation after irradiation, Pb: Permeation before irradiation

Figure 1 shows the permeation ratios of hydrogen andnitrogen at 573K before and after irradiation of various ions at
1x1012ion/cm2. The permeation of nitrogen was not changed
significantly by ion irradiation, but that of hydrogen decreased in
0.8 or less compared with that before irradiation, and theseparation ratio of hydrogen/nitrogen became small. Moreover,when the ion fluence was increased up to 1x1014ion/cm2, thenitrogen permeation also decreased to 0.9 compared with
un-irradiated samples.
Figure 2 shows the thickness change of the SiC thin film
according to the ion irradiation of Ni 15 MeV. The thickness
decreased over 20% at 1x1015 ion/cm2. It is likely that thedecrement of the film thickness was in proportion to the initial
thickness. Therefore the surface of the film was not reduced byion sputtering, but by the shrinking of the film in the thickness
direction. The SiC thin film has amorphous ceramic structure

Fig. 1. Change in the hydrogen and nitrogen permeation ratios at
573K after irradiation of a variety of ions at 1x1012ion/cm2.
Decrease of thickness (nm)1.

50Initial Thickness of SiC thin film
100nm

40

200nm
30
20
10
0
10 12

10 13
10 14
2
Fluence (Ions/cm )10 15

Fig. 2. Thickness change of the SiC thin film according toirradiation of Ni 15MeV.

－ 144 －

JAEA-Review 2007-060

4-03 Formation of Si Nano-crystals and Control of the Spatial
Distribution in Si-thermal Oxides
a)

a)

b)

b)

c)

H. Aiba , Y. Ohki , M. Nakamura , H. Nishikawa , T. Iwayama , Y. Ishiid)and T. Kamiya
a)

b)

d)

c)

d)

Waseda University, Shibaura Institute of Technology, Aichi University of Education, JAEA

Si nano-crystals attract much interest because of their unique electrical and optical properties. The formation of Si nanocrystals and control of spatial distribution are important in industrial devices. In this work, Si nano-crystals are fabricated in
Si –thermal oxide film by ion implantation and thermal annealing. We have measured the dependence of the size andphotoluminescence (PL) spectra of Si nano-crystals on the implantation doses. With increasing Si doses, the size of Si nanocrystals and the intensity of PL are increased, and the peak energy of PL is red shifted. This result indicates that size and PL
of Si nano-crystals are controllable by Si implantation dose.
リコンイオン注入にて作製した。熱処理により凝集したシリコンナノ結晶をAFM及びPL測定により観測し、作製した試料がシード層として利用可能であることを確認した。シリコンナノ結晶の大きさとPLスペクトルの強度は注入量の増加と共に増大し、ピーク波長はレッドシフトした。この結果から、注入量を制御することでシリコンナノ結晶の大きさと発光を制御できることが確認できた。今後は、本シード基板に対して電子線や高エネルギープロトンビームの照射を行い、局所的にシリコンナノ結晶を析出させる予定である。
Reference
1) T. Shimizu-Iwayama, et al., Nucl. Instrum. Methods B
230, 203 (2005).
40

80

30

60

20

40

10

20

0
2

3

4
5
6
16
2
dose [x10 ions/cm ]7

Width [nm]Height [nm]HeightWidth0
8

Fig.1 Height and Width of Si nano-crystals observed by
AFM. Solid lines and dashed lines are height and widthof Si nano-crystals, respectively.
7.0× 10 16 [ions/cm 2 ]350
PL intensity [ARB.UNITS]

半導体ナノ結晶は量子サイズ効果による特異な電気的特性や光学的特性を持つため、多くの注目を集め、
光･電子デバイスへの適用が検討されている。特に、その発光性や電荷蓄積機能を利用したエレクトロルミ
ネッセンス(EL)素子およびメモリ機能への適用は多くの注目を集めている。また、自然界に大量に存在するため環境負荷が小さく、半導体や集積回路において広く利用されているシリコンのナノ結晶は産業用途においても重要である。本研究の目的は、シリコンナノ結晶の形成と、その空間的な配置制御である。そのため、シリコン熱酸化膜(膜厚600 nm)に対してシリコンイオ
ン 注 入 (Si+, エ ネ ル ギ ー 200 keV, 照 射 量 :3-7×1016
ions/cm2)を行い、シリコンナノ結晶形成のためのイオン注入条件を検討した。さらに空間的配置制御のため、
電子あるいはイオンビーム照射によるシリコン結晶析
出が可能なシード基板の作成条件についても検討した。
実験では、窒素雰囲気中、1050 oCにおいて1時間の熱処理を行い、熱酸化膜中にシリコンナノ結晶を凝集させた 1) 。その後HFエッチングにより試料の表層300nm程度のSiO2を除去した後、原子間力顕微鏡(AFM)による表面観察を行った。また、顕微フォトルミネッセン
ス(PL)による光学特性評価(室温、488 nm励起)を行った。
イオン注入後のシリコン熱酸化膜を熱処理後にエッチングし、AFMにて表面状態を観察した。イオン注入
していない試料では、表面に析出物は観測されなかったのに対し、イオン注入した試料では、エッチング後の試料表面にシリコンナノ結晶の析出が観測された。
イオン注入量に対するシリコンナノ結晶の高さ及び幅をFig.1に示す。注入量が増加するにつれて析出する
シリコンナノ結晶の高さと幅が共に増大した。Fig.2にイオン注入及び熱処理後の試料のPLスペクトルを示す。イオン注入量の増加と共に、PL強度が増大し、ピーク波長は600 nmから690 nmにレッドシフトした。
発光強度の増大はFig.1に示すシリコンナノ結晶の粒径の増大と共に、発光種が増加したためと考えられる。
それと共に、量子サイズ効果あるいは界面の変化が生じ、発光種が変化することで、ピーク波長がシフトしたと考えられる。
電子ビームあるいはMeVイオンビーム照射効果を利用したシリコンナノ結晶析出のためのシード基板をシ

5.0× 10 16 [ions/cm 2 ]3.0× 10 16 [ions/cm 2 ]

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W avelength [nm ]

750

800

Fig.2 Photoluminescence spectra of Si nano-crystals
induced by ion implantation and thermal annealing.

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JAEA-Review 2007-060

4-04 Radiation Oxidation of Silicon-based Polymer Blends
A. Idesaki, R. A Wach, M. Sugimoto and M. Yoshikawa
Environment and Industrial Materials Research Division, QuBS, JAEA

H

H

C Si
H

H

CH3

C Si

CH3 m HCH3 1-m

Polycarbosilane

H

H

H

H

H

C

C Si

C

C

H

H

H

SiH 3 1-n

H n

Polyvinylsilane

Fig.1 Chemical structure of polycarbosilane (PCS) andpolyvinylsilane (PVS).

Radical concentration (1019 spins/g)

the irradiation at room temperature in air. Furthermore, atendency that the radical concentrations in PCS-PVS
polymer blends were below the straight line that links thepoints of 0 % PVS and 100 % PVS was shown.
The decay of radicals in case of the irradiation in air isconsidered to be attributed by the recombination of theradicals (partly crosslinking) and production of peroxides(-OOH). So, the radicals in the PCS-PVS polymer blends
may decay easily due to characteristics of the PVS such as
liquid, low molecular weight, and rich Si-H bonds, that is,high mobility of molecules and high reactivity of Si-H
bonds with oxygen. However, we can not distinguishclearly the recombination of radicals or the production ofperoxides as a reason to cause the decay of radicals for the
moment. Further investigation is necessary to know theradiation effects on the PCS-PVS polymer blends in detail.
3.5
3
2.5
2
1.5
1
0.5
0

0

20

40
60
80
PVS content (wt%)

100

Fig.2 The relationship between the radical concentrationsin PCS-PVS polymer blends and the PVS content after
the irradiation of gamma rays at 77 K in vacuum.

Radical concentration (1017 spins/g)

We have developed silicon carbide (SiC) coating forhydrogen gas separation membrane from a polymer blendof polycarbosilane (PCS) and polyvinylsilane (PVS). As
one of the processes for synthesis of SiC coating, the
PCS-PVS polymer blend is coated on the substrate, cured
by irradiation in air, and pyrolyzed in an inert gas
atmosphere. It has been found that the PCS-PVS polymer
blend can be cured by the irradiation in air with dose as
half as pure PCS. However, the mechanism of radiationoxidation curing of the PCS-PVS polymer blend has notbeen cleared. In order to clear the mechanism, it is useful
to investigate the radical behavior of the PCS-PVS
polymer blend because the radicals cause the oxidation
and/or crosslinking of the molecules. In this work, theradical behavior of the PCS-PVS polymer blends wasinvestigated.
Figure 1 shows the chemical structure of PCS and PVS.
The PCS is a solid polymer at room temperature and its
number average molecular weight is 2000. The PVS is aviscous liquid polymer at room temperature and its number
average molecular weight is 960.
The PCS-PVS polymer blends were irradiated by
gamma rays with dose of 0.2 MGy at liquid nitrogentemperature (77 K) in vacuum, and then the radicals in
PCS-PVS polymer blends were measured by an electron
spin resonance (ESR). The ESR measurements were also
conducted for the PCS-PVS polymer blends irradiated by
gamma rays with dose of 3 MGy at room temperature in
air.
Figure 2 shows the relationship between the radical
concentrations in PCS-PVS polymer blends and the PVS
content after the irradiation of gamma rays at 77 K in
vacuum. The radical concentration decreased linearly withincrease in the PVS content. This suggests that the PVS
does not affect on the production of the radicals in
PCS-PVS polymer blends. Figure 3 shows the relationshipbetween the radical concentration in PCS-PVS polymer
blends and the PVS content after the irradiation of gamma
rays at room temperature in air. Comparing with the resultin Fig. 2, the radical concentration in the PCS-PVS
polymer blends irradiated in air was low by a factor of 102.
This means that the produced radicals were decayed during

2.5
2
1.5
1
0.5
0

0

20

40
60
80
PVS content (wt%)

100

Fig.3 The relationship between the radical concentrationin PCS-PVS polymer blends and the PVS content after
the irradiation of gamma rays at room temperature inair.

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JAEA-Review 2007-060

4-05 Possibility of Silicon Carbide Micro-tube Synthesis from
Polycarbosilane-silicone Oil Blend Precursors
a)

a)

a)

b)

c)

K. Kita , M. Narisawa , H. Mabuchi , M. Itoh , M. Sugimoto and M. Yoshikawac)a)Division of Materials Science, Graduate School of Engineering, Osaka Prefecture Universityb)
Fukushima National College of Technologyc)Environment and Industrial Materials Research Division, QuBS, JAEA

A blend polymer of 85 mass% polycarbosilane (PCS) and 15 mass% poly-hydro methylsiloxane (H-oil) was prepared as
ceramic fiber precursor. Viscosity measurements on the blend polymer indicated that the blend polymer was sufficiently
melt-spinnable at temperatures of 543 and 573 K. Optical microscope observation indicated that the fiber spun at 543 K
was turbid, while the fiber spun at 573 K was transparent. IR spectra revealed that HS Low fiber (PCS – H-oil blend fiber
melt spun at 543 K) maintained original H-oil content during melt spinning process, while the H-oil content in HS High fiber(PCS – H-oil blend fiber melt spun at 573 K)decreased. After thermal oxidation or radiation curing and pyrolysis at 1273 K,
fibers with continuous pore structures were obtained. Continuous pore structure depends on spinning and curing conditions.
当研究グループではポリカルボシラン（PCS）と異種のポリマーをブレンド紡糸、放射線照射不融化、焼成することにより、より細い直径を有するSiC系繊維の合成などを行ってきた。この場合、PCSにブレンドされる前駆体は、PCSに良好な相溶性を示す一方、極めて高価、稀少であることが多い。近年、我々は、より低廉であり、一般的に入手しやすいシリコーンオイ
ルについてPCSとのブレンド時の挙動、繊維化について検討を開始した。
シリコーンオイル、シリコーン樹脂には極めて多くの種類があるが、一次元的な構造を有する通常のシリコーンは、セラミックス収率が極めて低い。繊維原料としてPCSに混合し、分散状態や不融化過程を制御することにより、繊維内部にナノレベルの細孔を形成できる可能性がある。
しかし、今までにこのような組み合わせについて、
相溶性、紡糸性、不融化法の適否、微細構造変化の傾向について、系統的な検討を行った例は無い。当研究ではこのようなテーマの追求を主体に、電子線照射、ガンマ線照射、および不融化時の雰囲気制御を組み合
わせて、研究を遂行中である。
PCS Polymer
HS15 Polymer

100
Relative Viscosity

Fig. 1に一例として、PCSに対して、Si-H基を側鎖に有するタイプのシリコーンオイルをブレンドし、加熱時の溶融粘度測定を行った結果を示す。粘度は単純に下方にシフトするのではなく、粘度が減少を始める
温度自体が低温側に移動していることが分かる。これはシリコーンオイルがPCSに対して、一部は相溶し、軟化剤として働いていることを示している。しかし543Kでの紡糸では、繊維は不透明な白色の外観を呈し、全てのオイルが相溶しているわけではないことも示された。相溶の限界はおおよそ10mass％程度と見積もられた。
低温紡糸により、わずかにオイルリッチなドメインを残した状態で電子線照射による不融化を行い、焼成後に繊維断面の観察を行った結果をFig.2に示す。オイルリッチ成分とPCSリッチな部位との間に三日月状の孔としてサブマイクロレベルの細孔が存在していることが分かる。ただし、放射線照射不融化がオイル自体にも働いてしまうため、細孔の形成が見られないケースもあり、良好な線量を選定する必要性を示して
いる。

80
60
40
20
0

533

553

573
593
Temperature / K

613

Fig. 1
Relative viscosity of PCS-H-oil
polymer blend with temperature rising.

Fig.2 Small crescent pores observed on the
cross section of HS15 Low fiber cured withelectron beam curing for 1.5h.

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JAEA-Review 2007-060

4-06 Effects of Ion Irradiation on Microstructural Change of
SiC Nanotubes
a)

a)

a)

b)

T. Taguchi , Y. Yamada , K. Kodama , S. Yamamoto , H. Yamamotoa)and S. Shamoto
a)

a)

b)

Neutoron Material Research Center, QuBS, JAEA, Environment and Industrial Materials
Research Division, QuBS, JAEA

Since the discovery of carbon nanotubes (CNTs) in 1991,
significant numbers of researches have prepared new
one-dimensional nanostructured materials such as nanotubes,
Si-C
C-C
SiCNT as recieved
SiCNTsirradiation
as receivedat 300C
nanorods and nanowhiskers for potential applications. Some
SiCNT
SiCNT
900C
SiCNTsirradiation
irradiation atat300ºCof them report that many nanomaterials such as TiC, NbC,
SiCNTs irradiation at 900 ºC
BN, C/C/N, SiO2 and GaN nanostructures are synthesizedfrom CNTs as the template materials. We reported that the
C-SiC coaxial nanotubes, which were CNTs sheathed with
SiC, were formed. Furthermore, the single-phase SiC
nanotubes were successfully synthesized by heating the
C-SiC coaxial nanotubes in air. SiC is the most important
semiconductor and has the excellent mechanical properties
at high temperature. These SiC nanotubes are expected to be
290
288
286
284
282
280
electrical devices and reinforcement materials used inradiation environments due to their excellent stability
against radiations. Until now, there have been many Fig.1 XPS of C 1s in the SiC nanotubes before and after 3.0
MeV Si2+ ion irradiation at 300 and 900 ºC.
researches about the effects of irradiation on the
microstructural change of SiC bulk materials. However, theeffects of irradiation on the microstructural change of theenergy difference between the peaks representing Si-C and
SiC nanostructure materials with peculiar shape such as SiC
C-C decreased with increasing the irradiation temperature.
nanotubes in this study have not been investigated. The
This result indicates that the binding state of SiC nanotubes
purpose of this study is, therefore, to investigate the effects
changed by the ion irradiation at higher temperature.
of ion irradiation on the microstructural change of SiC
Similarly, the results of XPS measurements of the Si 2p
nanotubes.
bands for the SiC nanotubes before and after ion irradiation
CNTs (GSI Creos Corporation, Tokyo, Japan) as theindicated that the peak representing Si-C existed in all
template materials and Si powder (The Nilaco Corporation,
specimens. The peak representing Si-O2 also existed in theTokyo, Japan) were used. The C-SiC coaxial nanotubes
specimen before ion irradiation. However, the peaks
were synthesized by the reaction CNTs with Si powder at
representing Si-O and Si-O2 disappeared by the ion
1200 ºC for 100h in a vacuum. Single-phase SiC nantoubes
irradiation.
were formed by the heat treatment of C-SiC coaxial
The TEM observation revealed that the SiC nanotubes
nanotubes at 600 º C for 2h in air. Thin films of
before ion irradiation were composed of the SiC grains withsingle-phase SiC nanotubes were prepared by embrocating
the size of a few nm to a few ten nm. Several single
with the single-phase SiC nanotubes dispersed in ethanol on
crystalline SiC nanotubes were formed by the ion irradiation
the alumina plates. These thin films of single-phase SiC
at 900 ºC. The result can be explained by the assertion that
nanotubes were irradiated by 3.0-MeV Si2+ ions at 300 ºC
the grain growth of SiC nanotubes was enhanced by the ion
and 900 ºC. The irradiation dose was 6.4x1020 ions/m2.
irradiation at such high temperature.
The results of X-ray diffraction measurements revealed
Referencesthat no change was observed by the ion irradiation at 300 º
1) T. Taguchi, N. Igawa, H. Yamamoto, S. Jitsukawa, J. Am.
C and 900 ºC .
Ceram. Soc. 88 [2] (2005) 459-461.
The XPS spectra of the C 1s bands for the SiC nanotubes
2) T. Taguchi, N. Igawa, H. Yamamoto, S. Shamoto, S.
before and after ion irradiation at 300 and 900 ºC are
Jitsukawa, Physica E 28[4] (2005) 431-438.
shown in Fig.1. There are two peaks representing Si-C and
C-C in all specimens before and after ion irradiation. The－ 148 －

JAEA-Review 2007-060

4-07 Fabrication of Blue-light Emitting Fused-silica Substrates
by Using Si-ion Implantation
a)

a)

a)

b)

b)

K. Miura , T. Tanemura , O. Hanaizumi , S. Yamamoto , K. Takano , M. Sugimotob)and M. Yoshikawa
a)

b)

b)

Faculty of Engineering, Gunma University, Environment and Industrial Materials Research Division,
QuBS, JAEA

Fabrication and Evaluation
Si ions were implanted into a fused-silica substrate (10mm x 10 mm x 1 mmt) at room temperature in TIARA. The
implantation energy was 80 keV, and the implantation
amount was 1 x 1017 ions/cm2 4). The Si implanted
substrate was cut into four pieces (0.5 mm x 0.5 mm x 1mmt) using a diamond-wire saw and they were annealed in
air for 25 min at 1100, 1150, 1200, and 1250oC by using asiliconit furnace. PL spectra were measured at room
temperature with excitation using a He-Cd laser (λ=325 nm).
A monochromator, a photomultiplier, and a lock-in
amplifier were used in our measurements. Figure 1 presents
the PL spectra of the four samples generated at room
temperature. Blue PL spectra having peaks around a
wavelength of 400 nm were observed from all the samples.
The peak wavelengths of the blue PL spectra of the samples
are almost the same in spite of the varying annealing
temperature. In our experiments, the blue PL peak had amaximum intensity after annealing at 1200 oC, and theintensity was 4.2 times higher than that of the peak of thelonger wavelength band of the sample annealed at 1100 oC.
Discussion
Liao et al. reported that a blue PL having a peakwavelength of 470 nm was observed from Si-ion-implanted
SiO2 films and stated that the blue-light emission may haveoriginated from an oxygen-defect level in SiO2 5). However,

the emission origin seems to differ from that of our samples
owing to the difference of the PL peak wavelengths. In
addition to a blue PL peak, a PL peak around a wavelengthof 800 nm in a wavelength range from red to infrared wasobserved for the sample annealed at 1100oC. In our
experiments, the Si-ion-implant conditions were almost thesame as those reported in ref. 4 and the annealing
temperature of 1100 oC is common to ref. 4, therefore it
seems that Si-ncs are also formed in this sample. There may
be a common origin of blue-light emission in these samples
and Si:SiO2 co-sputtered films 1). The SiOx layer located at
the interfacial region of Si nanoclusters and surrounding
SiO2 medium may contribute to such emission.
Blue-light-emitting materials are expected to be useful aslight sources for optical pick-up systems. Therefore, we aretrying to optimize the conditions of Si-ion implantation andannealing to improve the emission intensity and evaluate
optical gains of the Si-implanted samples.
References
1) O. Hanaizumi et al., Appl. Phys. Lett. 82 (2003) 538.
2) O. Hanaizumi et al., Jpn. J. Appl. Phys. 41 (2002) L1084.
3) Y. Yamada et al., Jpn. J. Appl. Phys. 35 (1996) 1361.
4) L. Pavesi et al., Nature 408 (2000) 440.
5) L. S. Liao et al., Appl. Phys. Lett. 68 (1996) 850.

PL Intensity(a.b.u.)PL Intensity[arb.
units]

Introduction
Various works on silicon (Si) based luminescentmaterials utilizing the quantum confinement effect, such as
Si nanocrystal (Si-nc), have been reported. Typicalfabrication methods of Si-ncs are co-sputtering of Si and
SiO2 1,2), laser ablation 3), and Si-ion implantation into SiO2
plates or thermal oxidized Si wafers 4,5). Pavesi et al.
reported that their samples including Si-ncs formed by using
Si ion implantation exhibited photoluminescence (PL) and alarge optical gain of 100cm-1 in a wavelength range from red
to infrared after annealing at 1100 oC 4). The optical gain isnearly equal to that of III-V semiconductors. Therefore, it
has recently been anticipated that light emission devices
composed of Si-nc-containing materials could be realized.
In this work, we fabricated Si-nc including fused-silica
substrates by using the Si-ion implantation method andannealing, and evaluated their PL properties.

* Annealing time: 25 min.
* Excited by using He-Cd laser (λ=325 nm)

0.12
1.2

Annealing Temperature

0.10
1.0

1200oC0.08
0.8

1250oC0.06
0.6

1150oC0.04
0.4

1100oC

0.2
0.02
0
0.00

300
300

400
400

500
500

600
600

700
700

800
800

Wavelength[nm]
Wavelength (nm)

900
900

Fig.1 Measured PL spectra. PL peaks around a wavelengthof 400 nm were observed from all the samples. The
longer-wavelength peak was reduced after annealing
above 1150 oC.

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JAEA-Review 2007-060

4-08 Effect of Impurity Co-implantation on Hydrogen
Surface Exfoliation
H. Iwataa,c), M. Takagi

b,c)and Y. Tokuda

a)

a)

b)

Department of Electronics, Aichi Institute of Technology, Department of Mechanicalc)Engineering, Aichi Institute of Technology, Research Institute for Industrial Technology, Aichi
Institute of Technology
SOI (silicon on insulator) fabrication has become an
attractive technology for low power, low voltage andhigh-speed electronics. Much attention has been given to thehydrogen exfoliation method introduced by Bruel 1) incomparison with other SOI fabrication techniques. Thismethod involves the micro slicing process of silicon by
high-dose hydrogen implantation and has advantages ofgreater uniformity of thickness and higher crystal quality ofthe silicon layer than other processes 1,2). Although thisunique and useful process has been extensively developed inindustrial applications during the past few years, thefundamental phenomenon and the underlying mechanism
are still not completely understood 3). Behaviors of
exfoliation on the surface were mainly examined by in-situ
microscopic experience. From these results, we attempt to
explain the relation between the defects distributions and theexfoliation phenomena, and report the effects of impurities(boron or fluorine) co-implantation.
Hydrogen ion implantation was performed in p-type
Cz-grown (100) oriented silicon. The implantation energy
was 80keV and hydrogen dose was 8×1016 H/cm2. After thehydrogen implantation, boron ion was implanted with
140keV. The projection rang (Rp) of boron is same depthwith the Rp of hydrogen.
These specimens were annealed at in-situ heating optical
microscopy (OM) experience. Annealing was carried out till
700° C. Defects distribution was estimated using crosssectional transmission electron microscopy (XTEM).
Exfoliated area of surface were evaluated by scanningelectron microscopy (SEM) and OM, and the depth of
exfoliation was obtained with scanning prove microscopy(SPM). The damaged layer caused by hydrogen ion
implantation is located in the region from 600nm to 800nm
depth from the surface. Increasing the doses of boron bellow
3×1014 B/cm2, the thickness of the damaged layer became
narrower. Bellow 3×1014 B/cm2 dosage, the number of
exfoliated pieces was proportional to the boron dose, andaverage exfoliated diameter was proportional to thehydrogen dose. The total exfoliated area was maximized at
3×1014 B/cm2 dosage. Over the 3×1014 B/cm2 dosage, thenumber of exfoliated pieces was inverse proportional to theboron dose, and average exfoliated diameter was inverse
proportional to the hydrogen dose. The total exfoliated area
was maximized at 3×1013 B/cm2 dosage. However, fromXTEM observation, long crack was observed in thedamaged layer of as implanted specimen. Using thiscondition, exfoliation with no annealing was observed.
Fluorine ion was implanted with 300keV. The projection
rang (Rp) of fluorine is almost coincident with the Rp of
80keV hydrogen. After the fluorine implantation, the defectdistributions were observed by XTEM.
In a fluorine dose range from 1×1016 F/cm2 to 5×1016
F/cm2, a thick amorphous layer is formed in the surface
vicinity. However, no differences were seen in the thicknessof amorphous layer.
In the case of H and F co-implantation (as shown in Fig.1),
crystal layer was found in the surface side. After the 700° C
annealing, it was found that the thickness of crystal layer
was proportional to the hydrogen dose. The result that
hydorgen has an important role of impeding theamorphization

References
1) M. Bruel, Electronics letters 31 (1995) 1201,
2) Q.Y. Tong, R.W. Bower, MRS Bulletin 23 (1998) 40
3) M.K. Weldon, et al., J. Vacuum Science Technology B
15(1997) 1065
Surface

(a)

(d)

(b)

(e)－ 100nm

Fig.1 Damage layers obtained by cross-sectional
TEM. (a): (H 1×1016 + F 1×1016) / cm2 as implanted.
(b): (H 3×1016 + F 1×1016) / cm2 as implanted. (c):(H 8×1016 + F 1×1016) / cm2 as implanted. (d): (H
1×1016 + F 1×1016) / cm2 as annealed. (e): (H
3×1016 + F 1×1016) / cm2 as annealed. (f): (H 8×1016+ F 1×1016) / cm2 as annealed.

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JAEA-Review 2007-060

4-09 Improvement of Gasochromic Properties in Tungsten
Oxide by Ion Irradiation II.
a)

b)

a)

K. Takano , A. Inouye , S. Yamamoto , A. Miyashitaa)and M. Yoshikawaa)a)Environment and Industrial Materials Research Division, QuBS, JAEA,b)
School of Engineering, Tohoku University

Tungsten trioxide, WO3, has gasochromic coloration inthat the color changes from yellow to dark blue in hydrogen
atmosphere. Fiber-optic hydrogen gas sensors using a
gasochromic WO3 film have been studied to support the safe
utilization of hydrogen as a clean energy source for theenvironment in recent years1,2). One of the subjects of theinvestigation in the WO3 film is large extent of thegasochromic coloration for satisfying the specifications ofhydrogen sensors. The gasochromic properties are
considered to relate to oxygen vacancies or defects in thetungsten oxide3). In our study, ion beam irradiations havebeen tried to make oxygen vacancies in WO3 thin films, anda possibility of the improvement in the gasochromiccoloration has been investigated.
WO3 thin films with the thickness of 0.4 μm wereprepared on quartz glass substrates by reactive rf magnetron
sputtering method with argon and oxygen mixture. After thedeposition, the films were annealed at the temperature of
400 ºC during 1 hour. The films were confirmed to havecrystal peaks by the measurement of x-ray diffraction. The
crystal structure was assigned to be monoclinic plane of
WO34). To investigate the gasochromic coloration of thefilms, a reduction of the intensity transmitted
630-nm-wavelength light was measured with an exposing of
1 % hydrogen diluted with argon gas. The typical reductionof the intensity at the exposure time of 600 seconds, that is,
the extent of gasochromic coloration, R0, was 15 %. 4He+
irradiations were performed in the fluence range from
5x1014 to 1x1017 ions/cm2 at room temperature using the ion
implanter at JAEA/Takasaki. The incident energy was
selected 40 and 350 keV. After the irradiations, the extent ofgasochromic coloration, R, was measured with the sameprocedure to the case of R0.
In the previous report with x-ray photoelectron
spectroscopic analysis5), 20 % of the tungsten atoms in WO3film changes to oxygen-deficient tungsten caused by the 350
keV He+ irradiation at the fluence of 1x1017 ions/cm2. Here,it is supposed that the oxygen vacancies of 1.1x1022
number/cm3 are created at the fluence of 1x1017 ions/cm2, as
the theoretical density of oxygen atom in WO3 is 5.7 x1022
number/cm3. In the case of 40 keV irradiation, the amountof the oxygen vacancy is expected to be 8.2-fold of that in
350 keV from a calcuration6) with theoretical density of
monoclinic WO3, 7.29 g/cm3. Assuming that the amount ofoxygen vacancy is proportion to the fluence of 40 and 350
keV irradiation, the oxygen vacancy dependence of thegasochromic coloration is shown in Fig. 1. The value of R

increases with increasing of the oxygen vacancy. At theamount of oxygen vacancy from 1x1022 to 5x1022
number/cm3, which is equivalent from 1 to 9 % of oxygen
atoms in the WO3 film, R has the maximum to be more than
3-fold of R0. However, in the range above 5x1022
number/cm3, R returns to R0. From this result, it isconcluded that the optimum number of oxygen vacancy forhigh extent of the gasochromic coloration in WO3 films
exists.
Ion irradiation to WO3 films was found to improve theirgasochromic coloration by introducing oxygen vacancies,and expected to achieve high performance of gasochromichydrogen sensor based on the WO3 films.
References
1) K. Ito and T. Ohgami, Appl. Phys. Lett. 60 (1992) 938.
2) K. Takano, et al., Trans. Mater. Res. Soc. Jpn. 31(2006) 223.
3) A. Georg, et al., Thin Solid Films 384 (2001) 269.
4) B. O. Loopstra and P. Boldrini, Acta Cryst. 21 (1966)
158.
5) K. Takano et al., Trans. Mater. Res. Soc. Jpn. 32(2007) 159.
6) J. P. Biersack and L. Haggmark, Nucl. Instr. and Meth.,
174 (1980) 257.

Fig.1 Oxygen vacancy dependence of gasochromiccoloration on WO3 film with He+ irradiations. R0 and
R is the extent of gasochromic coloration for theunirradiated and irradiated film, respectively.

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JAEA-Review 2007-060

4-10 Structural Change of Gasochromic WO3 Films
by Hydrogen Incorporation
A. Inouyea), b)

b)

c)

b)

b)

, S. Yamamoto , S. Nagata , K. Takano , M. Yoshikawa

and T. Shikamac)a)School of Engineering, Tohoku University
Environment and Industrial Materials Research Division, QuBS, JAEA
c)
Institute of Materials Research, Tohoku Universityb)

Structural change of the gasochromic WO3 films by hydrogen incorporation was investigated. (0 1 0)-oriented monoclinic
WO3 films were prepared by a sputtering method on SiO2 substrates. When the light green color of Pd coated WO3 films
turned to dark blue by exposure of 1 % H2-N2 gas, the monoclinic WO3 structure changed to a tetragonal structure. The
results of elastic recoil detection analysis (ERDA) and Rutherford backscattering spectroscopy (RBS) revealed that thehydrogen concentration increased 0.2 H/W in the samples during hydrogen exposing. These results indicate that thecoloration of the WO3 by hydrogen gas is caused by incorporation of hydrogen, with formation of hydrogen tungsten bronze(HXWO3).
と考えられる。したがって、酸化タングステンの水素による着色メカニズムとしてHXWO3の形成によって着色するモデルを支持する。

m-WO ( 2 0 0 )2 3 .0tetra-H

(020)

3

3
0.23

WO

WO

0.23

tetra-H
2 2 .5

(001)

(b )

2 2 .03

3

Intensity / a. u.

3

m-WO ( 0 0 2 )(a )m-WO ( 0 2 0 )References
1) S. H. Lee, et al., Electrochimica Acta 46 (2001)
1995-1999.
2) A. Georg, et al., Solid State Ionics 127 (2000) 319-328.

2 3 .5

2 4 .02 4 .52 5 .02 θ / d egree

Fig. 1. XRD patterns of the oriented WO3 film s(a) as-prepared and (b) colored states.

25

20
Yield / counts

パラジウム（Pd）などの触媒を表面に担持させた三酸化タングステン（WO3）は、水素と反応することで着色する特性（ガスクロミック特性）を示す。この着色メカニズとして、触媒によって解離した水素原子がWO3 の結晶格子中に侵入し、タングステンブロンズ（HXWO3）が形成されて着色するモデル1)と、或いは水素により酸素欠損を形成されて着色するモデル2)など、いくつかのモデルが提案されている。しかし、着色メ
カニズムは十分には理解されていない。そこで本研究
では、結晶配向性酸化タングステン膜を用いて着色前
後における結晶構造変化と水素挙動の関連性を調べ、着色メカニズムを追求した。
試料作製には反応性RFマグネトロンスパッタ法を用いた。アルゴン/酸素混合ガス中で金属タングステンタ
ーゲットをスパッタし、600 ℃に保持した石英基板上に酸化タングステン膜（約 550 nm厚）を堆積した。その表面に約 15 nmのPdを蒸着したものを試料とし、1 %の水素を含んだ窒素ガス（1%H2-N2）に曝して着色させた。着色前後における結晶構造をX線回折法（XRD）により評価し、水素濃度の定量にはラザフォ
ード後方散乱法（RBS）および反跳粒子検出法（ERDA）を用いた。
作製試料の着色前後におけるX線回折パターンを
Fig.1 に示す。着色前では、2θ=23.6o付近に単斜晶系WO3（0 2 0）に由来する回折ピークが観測された（Fig.1(a)）。
これは作製試料の結晶構造が単斜晶系WO3（0 1 0）に一軸配向していることを示している。この試料を1%H2-N2に 20 分間さらし着色させると、X線回折パターンは変化し正方晶系H0.23WO3（JCPDS No.42-1261）に対応した（Fig.1(b)）。
Fig.2 は、着色前後における膜中水素の深さ分布を示す。着色前における試料のスペクトル形状およびピー
ク強度から、膜中には水素が一様に含まれており、その濃度は 0.6 H/W（13at.%）と見積もることができた。
着色後では、膜中の水素濃度は約 0.2 H/W 増加した。
以上のことから、酸化タングステン膜のガスクロミ
ック着色は、膜中への水素の侵入が伴っており、正方晶系タングステンブロンズの形成と深く関係している

WO 3 film

15

(b)

10

5

0

(a)

200

400

600

800

1000

1200

energy / keV

Fig. 2. Hydrogen depth profiling in the oriented WO3
films (a) as-prepared and (b) colored states.

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JAEA-Review 2007-060

4-11 Effect of Annealing Temperature of Palladium Oxide
Films on Hydrogen Detectiona)a)S. Yamamoto , K. Takano , A. Inouyea), b)and M. Yoshikawaa)a)Environment and Industrial Materials Research Division, QuBS, JAEA,b)
School of Engineering, Tohoku University

The fast detection of hydrogen leaks below the lower
explosive limit (LEL) of 4 % by volume ratio of hydrogenin air is an important technology. Hydrogen sensors basedon electrical properties of metal oxides have been developed.
However, a hydrogen sensor, which can safely detect atroom temperature, with a low cost and lightweight, isdesirable. Recently, the gasochromic materials, coloration
by gases, have considerable promise as the optical hydrogensensing films. Palladium oxide films coated with noble
metal (Pd, Pt) catalysts were expected to have gasochromiccoloration, since it is known to exhibit optical absorbancechanges due to the reduction with hydrogen.
Palladium oxide films are prepared by thermal oxidationof polycrystalline Pd films deposited on quartz substrates
using an rf magnetron sputtering. The Pd films wereannealed at temperatures range from 300 to 900 °C in air.
For the gasochromic coloration measurements, thetransmittance of palladium oxide films coated with Pd
catalyst (15 nm thickness) was measured using aspectrometer with a fiber optics at a wavelength of 645 nm
from a light-emitting diode. To confirm the detection ofhydrogen less than LEL, the samples were exposed in 1 %H2/Ar flow of 100 sccm. The composition of palladiumoxide films was determined by the RBS using a 3 MV
single-stage-accelerator at JAEA/Takasaki.
Figure 1 shows optical response curves of gasochromiccoloration for the palladium oxide films with 32 nm
thicknesses annealed at 600 °C, (a) coated with Pd catalyst,
and (b) without Pd catalyst, respectively. The transmittanceTransmittance T/T0

Transmittance T/T0

(b)

1

0.5

(a)
0

T at a wavelength of 645 nm was measured as a function of
exposure time of hydrogen. T0 is the transmittance at the
beginning of the measurements. The normalized
transmittance T/T0 of the film with Pd catalyst is rapidly
decreased down to 0.1 within 2 min. The result shows that
the Pd catalyst on palladium oxide film causes gasochromiccoloration for hydrogen at room temperature.
The dependence of gasochromic performance onannealing temperature of polycrystalline Pd films is shownin Fig 2. The T/T0 of the films on quartz substrates was
taken after exposure 20 min in 1 % H2/Ar. The T/T0 of thefilms is decreased with increasing annealing temperaturesand reaches to a minimum at 600°C. This result indicatesthat the palladium oxide film with superior gasochromic
performance for hydrogen was obtained by annealing at
600°C in air. It is found that the gasochromic coloration of
palladium oxide films for hydrogen is strongly influenced
by annealing temperature. The composition of the palladiumoxide films with different annealing temperatures was
examined by the RBS. Polycrystalline Pd films (64 nm
thickness) were annealed at temperatures range from 200 to
600°C in air for 1h. The results of RBS indicate the Pdphase remains up to at 200 oC and begins to oxidize ataround 250 oC and then becomes completely oxidized at 450oC with formation of PdO phase. Palladium oxide film with
PdO phase obtained by annealing at 600°C in air shows theappropriate gasochromic performance for hydrogendetection.

1

0.5

0

0

100

200

300

400

600

800

Annealing temperature (°C)

Time (sec)Fig. 1 Optical response of the coloration for the palladiumoxide films in 1 % H2/Ar. (a) with Pd catalyst and (b)without Pd catalyst.

Fig. 2 The dependence of gasochromic performance onannealing temperature of polycrystalline Pd films.

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4-12 Improvement of Hydrogen Storage Characteristics ofPalladium by Ion Irradiation
a)

b)

b)

H. Abe , S. Aone , R. Morimoto , H. Uchidab)

and T. Ohshima

a)

a)

b)

Environment and Industrial Materials Research Division, QuBS, JAEA
Department of Applied Science, Graduate School of Engineering, Tokai University

In previous studies, the induction of vacancy in palladium(Pd) was found to be effective for an increase in thehydrogen absorption rate1, 2). Regarding the hydrogenstorage in metals, it was reported that the absorption
concentration of hydrogen atoms and the hydrogen
absorption rate depend strongly on the surface state ofmetals1). For the surface modification of materials, ion
implantation with low energy is known to be a quite useful
method. These facts give the possibility that the hydrogen
absorptivity in Pd is improved by surface modification using
ion irradiation.
In this study, we perform chromium (Cr) ion irradiation
into Pd, and the hydrogen absorption rate of ion irradiatedPd was evaluated. Based on the obtained results, we discuss
the correlation among ion irradiation, work function andhydrogen absorption in Pd.
The samples used in this study were Pd sheets (99.99 %purity, 7.5 x 7.5 x 0.1 mm3). Prior to ion irradiation, allsamples were annealed in nitrogen atmosphere for an hour
at 1173 K. Cr ion (Cr+) irradiation onto the Pd samples
was made at room temperature using the ion implanter at
TIARA. The acceleration energy of Cr+ and the maximum
fluence were 350 keV, and 1 x 1017 /cm2 respectively. The
hydrogen absorption rate of the irradiated Pd wasinvestigated using an electrochemical method. Pd wasused as a cathode, and an Hg/HgO was used as the referenceelectrode. Details of the electrochemical measurements
have been reported elsewhere3).
Figure 1 shows the hydrogen absorption curves of Pd
samples before and after 350keV-Cr+ irradiation. With
increasing Cr+ fluence, the hydrogen absorption rateincreased. The sample irradiated at a dose of 1 x 1017 /cm2

exhibited a much higher rate than the others, and thehydrogen absorption rate of the Pd became five times higher
than that of un-irradiated Pd. Since vacancy type defects
are introduced by irradiation and such vacancies might act
as hydrogen trapping sites, the enhancement of the hydrogen
absorption rate obtained in this study can be interpreted interms of an increase of hydrogen trapping sites near thesurface region due to irradiation of Cr+ into Pd.
Figure 2 shows the relationship between the work
function of Pd (Δφ) and the hydrogen absorption rate before
and after Cr ion irradiation. The value of Δφ is depicted asa shift from un-irradiated sample. The shift of the Δφ isestimated from Δφ = VE / (ΔV - 1), where VE is thepeak-to-peak output voltage and ΔV represents the voltage
difference between the probe tip and Pd sample. By Cr+
irradiation, Δφ shifts to the negative side. As for thehydrogen absorption rate, the value increased withincreasing fluence of Cr ions. These results imply that thevalue of Δφ decreases and the hydrogen absorption rateincreases with increasing vacancy concentration.
In summary, Cr ion irradiation with energies of hundred
keV is useful for the improvement of the hydrogen
absorption rate of Pd.
0.01
un-irradiated350 keV Cr + 1e16 cm-2

0.008

+

350 keV Cr 1e

17

-2

cm

0.006
0.004
0.002
0
-0.15

0.03

-0.1

-0.05

0

0.05

Change in work function Δφ [eV]1x10171x10161x1014
non-irradiated

0.025
0.02

Fig.2. Relationship between the work function of Pd(Δφ) and the hydrogen absorption rate before and after
Cr ion irradiation.

0.015
0.01
0.005
0

0

20

40

60

80

100

120

Time [min]Fig.1. Hydrogen absorption, 5 cycles, curves of Pd
irradiated with 350keV Cr+ at doses from 1x1014 /cm2
to 1x1017 /cm2.

References
1) H. Abe, A. Uedono, H. Uchida, A. Komatsu, S. Okada
and H. Itoh, Mat. Sci. Forum, 363-365 p. 156 (2001).
2) H. Abe, H. Uchida, Y. Azuma, A. Uedono, Z. Q. Chen
and H. Itoh, Nucl. Inst. and Meth. B, 206 p. 224(2003).
3) H.H. Uchida, Y. Watanabe, Y. Matsumura and H.
Uchida, J. Alloys Comp., 231 p. 679 (1995).

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JAEA-Review 2007-060

4-13 Gamma-ray Irradiation Effect on Lattice Defect Centers
Detected from the Tsurukawa Fault Gouge, JapanT. Fukuchi and D. Tanaka
Department of Earth Sciences, Graduate School of Science and Engineering, Yamaguchi University
ESR dating of fault movements. According to X-ray
diffraction analysis, this unknown center may be derived
from another clay mineral such as illite. To identify thisunknown center, we need to carry out more detailed
experiments such as comparison with ESR signals detectedfrom standard clay minerals.
T-3
28000

g=2.0122

2.00392.0015

1.9973

0 kGy

24000

ESR Intensity (arbitrary

1 kGy
2 kGy

20000

3 kGy
4 kGy

16000

5 kGy
6 kGy

12000
7 kGy
8 kGy

8000

9 kGy
10 kGy

4000

0
2.035

2.025

2.015

2.005

1.995

1.985

1.975

g-value

70000

g=2.0123

T-4

2.0041
1.9973

60000

0 kGy

1 kGy
2 kGy

ESR Intensity (arbitrary

A well-known method for the assessment of fault
activity (i.e., seismicity) is the ESR (electron spinresonance) dating method using lattice defect centers
detected from intrafault material (fault gouge)1). Clayminerals such as smectites in fault gouge are considered to
be produced at almost the same geological time as thefractures of host rocks during fault movements, so that ESRages obtained from the clay minerals may directly show theages of fault movements. In this report, we investigate γrays irradiation effect on ESR centers detected from thefault gouge along the Tsurukawa fault, which is distributed
from Yamanashi to Kanagawa Prefecture, and consider
whether or not the ESR centers can be used for ESR datingof fault movements. The experimental fault gouge samples
were collected from an outcrop along the Kaisawa River,Tabayama Village, Yamanashi Prefecture. At this outcrop, a
black fault gouge layer (T-3) has been formed along thefault plane that may have been most active at the latest fault
movement, and dark gray gouge layers (T-2, T-4) are
positioned on both sides of the black fault gouge.
Furthermore gray gouge layers (T-1, T-5) are distributed
outside the dark gray gouge layers. The source rock of thesefault gouge samples is pelite.
The γ-irradiation was carried out using a 60Co source inthe 6 cell irradiation facility, Takasaki Advanced Radiation
Research Institute, JAEA. The dose rate and time ofirradiation are 23.7 C/kg/h (0.97 kGy/h) and 0~10 hours.
ESR measurements were carried out using an X-band ESR
spectrometer with a 100 kHz modulation field (JEOL RE3X) in Yamaguchi University. As a result of ESR
measurements, paramagnetic Fe3+ and Mn2+ ions signals aredetected from all the fault gouge samples. In addition, ESR
signals (g=2.0123, 1.9973) intrinsic to smectites, an E’center (g=2.0015) derived from oxygen vacancies, anorganic radical center (g=2.0039), and an unknown ESR
signal (g=2.0041) are detected especially from T-3 or T-4
sample. Figure.1 shows variations of ESR spectra obtained
from T-3 and T-4 samples before and after γ-irradiation. As
shown in the figure, the ESR signals intrinsic to smectites
regularly increase with γ-irradiation. This result means that
the ESR signals of smectites are applicable to ESR dating offault movements. On the other hand, the E’ and organic
radical centers irregularly change by γ-irradiation. There
have been hardly experimental data on the γ-irradiation
effect on organic radical centers. Our result indicates thatthe organic radical centers are not available for ESR dating.
Furthermore, the unknown ESR center at g=2.0041 clearly
increases with γ-irradiation, so that it may be applicable to

50000

3 kGy
4 kGy

40000

5 kGy
6 kGy

30000

7 kGy
8 kGy

20000

9 kGy
10 kGy

10000

0
2.035

2.025

2.015

2.005

g-value

1.995

1.985

1.975

Fig.1 Variations of ESR spectra obtained from the
Tsurukawa fault gouge samples (T-3 and T-4) by γrays irradiation. The dose rate of irradiation is 23.7
C/kg/h. The irradiation time is 0~10 hours.
Reference
1) T. Fukuchi (2004) ESR dating method of fault
movements- Its principle and practice. Fukadaken
Library, No.63, 45pp.

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JAEA-Review 2007-060

4-14 Provenance Study of Eolian Deposits Using Electron Spin
Resonance Signal Intensity and Crystallinity of Quartza)a)R. Tada , Y. Isozaki , Y. Sunb)

and K. Nagashimac)a)

Department of Earth and Planetary Sciences, Graduate School of Science, University of Tokyo,c)Institute of Earth Environment, Chinese Academy of Sciences Institute of Observational Research
for Global Change, Japan Agency for Marine-Earth Science and Technologyb)Inland desert areas of western China such as Taklimakan and Gobi are special for their distribution in higher latitudes, andit has been suggested that uplift of Himalaya and Tibet is a cause of their formation based on paleoclimatic model
simulations. Thus, specification of the timing and mode of formation of these deserts is critical to test the potential linkage
among the uplift of Himalaya-Tibet, the evolution of Asian monsoon and the formation of deserts in inland Asia. Then, we
aim to reconstruct past provenance changes of aeolian deposits in East Asia in order to examine the timing of formation ofthese deserts and the evolution of Asian monsoon. In order to estimate the provenance of aeolian deposits, we focused on
Electron Spin Resonance (ESR) signal intensity and crystallinity index of quartz, which are powerful methods to constrain
on the provenance of dust deposits. Here we first determine the procedure of gamma-ray irradiation for ESR analysis.
ヒマラヤ・チベットの隆起に伴ってアジア内陸部（タクラマカン、ゴビ砂漠域）が乾燥化すると共にアジア・モンスーンが強化されたとする仮説は古くから提唱されてきた。しかしながら、ヒマラヤ・チベットの隆起時期や様式、アジア・モンスーンの強化時期や発達の様式に関する地質学的証拠が不十分であったた
め、この仮説は十分検証されていない。そこで本研究の目的は、アジア内陸部の乾燥化やアジア冬季モン
スーンの開始時期・発達過程を調べ、ヒマラヤ・チ
ベットの隆起に伴う乾燥化およびアジア・モンスーン
強化の可能性を検証することにある。そのために、冬季モンスーン風および偏西風によりアジア内陸部の乾燥域から運ばれる風成塵に注目し、風成塵の起源とその時代変遷を復元して、アジア内陸部の乾燥化および
アジア・モンスーン強化の時期や様式を検証する。
風成塵の供給源推定に際して注目したのが、石英の電子スピン共鳴(Electron Spin Resonance; ESR)信号強度
および結晶化度である。石英のESR信号強度は、母岩の形成年代を反映する指標と考えられている1)。一方、石英の結晶化度は、石英の生成環境を反映する指標と考えられている ２)。そこで我々はこれらの指標を組み合わせて、風成塵の供給源推定を行う。
本研究は平成18～20年度の3年間で行われ、初年度である平成18年度は、中国黄土高原の風成堆積物を用いて、ESR信号強度の測定条件の検討を行った。ここでは、ESR分析に際して行うγ線照射の条件設定のための予備実験結果について簡単に述べる。
ESRとは物質中の不対電子が静磁場中でマイクロ波を吸収する性質を利用して、不対電子を検出する手法である。本研究では石英中に生成されるE1’中心と呼ばれるESR信号に注目した。E1’中心とは、結晶中の酸素空格子に、１つの不対電子が捕らえられている状態である。E1’中心のESR信号強度とは、この格子欠陥を
ESRによって測定したものである。E1’中心の信号強度
は、石英を過熱すると300 ℃までは増加する。これは電子を2個とらえ安定な状態で存在する酸素空格子が、加熱によって放出された電気的ホールを１個とらえ、常磁性のE1’中心に変化するためであると考えられている 3) 。つまり事前にγ線を照射し、石英中に十分な量の電気的ホールが存在する状態で過熱を行えば、電気的ホールが酸素空格子へ移動し、石英中のすべての酸
素空格子がE1’中心として存在するようになる。沖縄で採取された花崗岩を用いた先行研究3)では、約1 kGyのγ線照射と加熱によって、E1’中心のESR信号強度が飽和に達することが示されているが、東アジアの風成堆積物の場合、1 kGyで飽和に達するのか否かが明らかになっていない。そこで中国の黄土高原から採取された7つの風成堆積物試料について、それぞれ1kGyと2.5
kGの2通りの照射を行い、ESR信号強度の差を検証した（Fig.1）

ESR Signal Intensity
after 1.0 kGy Irradiation (1015spin/g)
Fig.1 Comparison between ESR signal intensity forsamples irradiated 1kGy and 2.5kGy.
その結果、照射量を変えてもESR信号強度には有意の差が見られず、1 kGyで飽和に達していること、また照射量を増やしても（少なくとも2.5 kGyまでは）人工的なE1’中心の生成は起こっていないことが明らかになった。以上の結果から、1-2.5 kGyの範囲でのγ線照射は、我々の目的に沿うものであることがわかった。
References
1) S.Toyoda, Ph. D. Thesis, 106pp., Osaka University(1992).
2) K. Murata and M. Norman, Am. J. Sci., 276, 1120-1130(1976).
3) S. Toyoda and W. Hattori, Applied Radiation and
Isotopes, 52, 1351-1356 (2000).

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JAEA-Review 2007-060

4-15 Preparation of Anisotropic Conductive Membranes
Using Ion Beam Irradiation
H. Koshikawa and Y. Maekawa
Environment and Industrial Materials Research Division, QuBS, JAEA

R = 1/ S =ρL

π (d /2)2 AF

where ρ is a resistivity of copper (1.67x10-6 Ωcm), L islength of copper wires, d is a diameter of the copper wires,
A is an area of the electrode, and F is a particle fluence.
Somewhat lower conductivity of the PI/Cu composite
films compared with the theoretical value is likely to result
from the defects in copper wires during the electroplating
preparations, influence of the interfaces between copper
wires and the pore surfaces of PI, and/or the contact
resistances between the Au dots and the top of copper wires.

Table 1 Resistance that calculated the area of eachelectrode and the magnification to the theoreticalresistances of measurements
Theoretical
Measured
Area of the
Ratio
resistance, A
resistance, B (B/A)
electrode
cm2
1.2 x10-3
2.7 x10-3
2.3 x10-3
2.8 x10-3
3.1 x10-3
4.2 x10-3
3.5 x10-3
3.3 x10-3

1
2
3
4
5
6
7
8

Count

The damaged region created along the path of swift
heavy ions in polymers is susceptible to a proper etchant,
resulting in the formation of through-holes withnanometer-to-micrometer diameters. This so-called ion
track membranes of thermally and mechanically stable
polymers have been developed for applications to electronic
devices through hybridization with metals andsemiconductor alloys by electroplating1,2). In this study,
anisotropically conducting membranes were prepared byelectrochemical deposition of copper (Cu) wires into thecylindrical pores in the polyimide (PI)-based ion track
membrane. We report here the conductivity of PI/Cu
composite films with low fluence Cu wires.
Commercially-available PI films (Kapton, thickness: 12µm) were irradiated by 450 MeV 129Xe23+ with fluences of
3×103 and 3×105 ions/cm2 from the AVF cyclotron at the
TIARA facility. According to the established procedure3),
the PI ion track membranes with 0.5 – 2.0 µm diameter
cylindrical pores were then prepared by the etching in aaqueous sodium hypochlorite (NaClO) solution at 60°C.
Successive layers of gold (25 nm) and Cu (20 µm) were
coated on one side of the ion track membranes as a cathode4).
The Cu wires were deposited within the pores of the ion
track membranes onto the Cu cathode by electrochemical
plating in a pH1 aqueous solution of 1.3 M copper sulfate(CuSO4). The dot of Au electrodes with 0.3 - 0.5 mm indiameter was deposited on the other side of the Cu cathodeto connect with copper wires of the PI/Cu composite films.
The Au dot electrodes were connected to two terminals of
milliohmmeter via Au wires, then electrical conductivity of
the PI/Cu composite films was measured.
The electric resistances of the ion track membranes withpores of 0.5 μm in diameter and a fluence of 3.0 x 105
ions/cm2 were measured using the dot electrodes in 8 placeson the PI/Cu composite films. The measured (B) andtheoretical (A) resistances and these ratios (B/A) wereshown in Table 1. Theoretical resistances were given by thenext equation,

mΩ
2.8
1.3
1.5
1.2
1.1
0.8
1.0
1.0

mΩ
23
7.2
8.3
11.8
8.4
6.9
7.2
7.2

8.3
5.7
5.6
9.8
7.7
8.5
7.5
7.0

9
8
7
6
5
4
3
2
1
0
5

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

C o n d u ctiv ity (S )Figure 1 The histogram of the distribution of 21 pointsof the measured conductivity in the composite films
with the copper wires; fluence: 3x103 ion/cm2,
diameter: 2µm.
Thus, we used the samples with low density of Cu wires(3x103 ion/cm2) with low resistance of each wire (2µm in
diameter) in order to obtain the resistivity information of
single wire.
Figure 1 shows the histogram of the distribution of themeasured conductivity of 21 points of the PI/Cu composite
films with pores of 2 μm and a fluence of 3x103 ion/cm2.
There was three distributions with peaks at conductivities of15, 35 and 55 S with the equal intervals. These peakconductivities are in good agreement of the integral multipleof the theoretical conductivity of one copper wire of about
17 S. It was considered that the copper nanowires in thecomposite membranes formed by using the ion track films
had the conductivity equal with the bulk. However, lower
conductivity of the PI/Cu composite films with pores of 0.5
μm in diameter should results from some of the wires are
not connected to the Au dot electrodes.
References
1) C.Trautmann et al., Nucl. Instr. Meth. B111 (1996) 70.
2) T.Molares et al., Adv. Matter., 13 (2001) 62.
3) Y. Maekawa et al., Polymer, 45 (1996) 2291.

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4-16 Development of Optical System for Direct Observationof Behavior of Transient Species under Pulsed-heavy
Ion Irradiation
a)

a)

a)

b)

M. Taguchi , A. Kimura , K. Hirota , S. Kurashima , G. Baldacchinod)and Y. Katsumura
a)

c)

b)

Environment and Industrial Materials Research Division, QuBS, JAEA, Department ofc)Advanced Radiation Technology, TARRI, JAEA, Laboratoire de Radiolyse,d)
DSM/DRECAM/SCM/URA331CNRS, CEA/Saclay, Department of Nuclear Engineering andManagement, School of Engineering, The University of Tokyo
1. Introduction
High energy heavy ion irradiation induces characteristic
chemical reactions in water, which are considered to becaused by high concentrations and heterogeneous reactionsof radicals in track. Hydroxyl(OH) radical is the mostimportant radical for oxidations in water. We reported thedependence of the differential G-values of OH radicals on
the energy and mass of the incident ions, and on the elapsed
time by the product-analysis method1). In order tounderstand precisely the reactions in track, direct
observation method is more useful and informative. We
construct the optical system under the pulsed heavy ion
irradiation.
2. Experimental
Carbon ion with 220-MeV energy was selected toevaluate and improve the specification of the constructed
optical system. As shown in Figure 1, C ion beam from an
ion source was bunched by a chopper to obtain the shortpulse with a width of several μs to 1000 μs, which wascontrolled by a pulse generator. Time profile and charge ofthe pulse were directly measured by Faraday cup set at theupper stream of the beam in vacuum. Sample cell was
horizontally set on the optical stage under the window for
extracting the ion from vacuum. The sample cell has two
glass windows with 50-μm thickness for the ion irradiationand optical measurement on the top and bottom. Probe light
was introduced into the sample cell with an angle of 30

degree against the ion beam axis, and reflected by mirror
under the cell. Light intensities observed by a photodiodewith and without irradiation are defined as I and I0,
respectively. Absorbance due to produced radicals is
estimated by Lambert-Beer equation (OD=log(I0/I)).
Improving optical system and reducing electric noise makepossible to measure a small absorbance less than 10-4.
KSCN dissolved in water was used as sample solution,
because its reaction mechanism is well known and primaryradical has a large extinction coefficient.
3. Results and discussion
Time dependent absorbance was recorded at 447 nm foraqueous KSCN solution irradiated with C ion as shown in
Figure 2. OH radicals produced in the track react with soluteto produce (SCN)2-, and absorbance shown in Figure 2 isassigned to (SCN)2-. Rise time of absorbance from time 0 iscompletely the same as the irradiation pulse width. Increasein absorbance with pulse width implies that (SCN)2- isrelatively stable and its concentration increases. Saturation
observed for the longer pulse irradiation demonstrates thecompetition between the formation and decomposition of(SCN)2-.
Reference
1) M. Taguchi and T. Kojima, Nuclear Science andTechniques, 18 (2007) 25.

AbsorbanceC ion pulse width

500 μ s
193
91
40
20

0.002

0.001

0
0

1000

2000

3000

Time / μ s

Fig. 1 On-line optical measurement system for pulsed
heavy ion irradiation.

Fig. 2 Time dependent absorbance for 10-mM aqueous
KSCN solution irradiated with C ions having
different pulse widths.

－ 158 －

JAEA-Review 2007-060

4-17 LET Effect on Irradiation of Hydroxymaleimide in
Alcohol Solution
a)

b)

a)

b)

S. Nakagawa , N. Ohta , M. Taguchic)and K. Hirotac)

TMITRI, Hiroshima Univ.,c)Environment and Industrial Materials Research Division, QuBS, JAEA
Hydroxymaleimide was irradiated in 2-propanol and methanol solutions with 350 MeV Ne-ion, 220 MeV C-ion, 100 and
50 MeV He-ion beams from the AVF cyclotron in the TIARA Facility. The differential G-values of the reduction ofhydroxymaleimide decreased with increasing LET. The LET dependence by He-ion shifted from heavier ions. This effectclearly appeared in methanol solution.
0.1

Apparent G-value＜はじめに＞ マレイミド(C2H2(CO)2NH)は、光化学重合反応の開始剤として研究が行われてきた。一方、ヒドロキシマレイミド(C2H2(CO)2NOH)を2-プロパノール
およびメタノール中でγ線照射したところ、溶媒分子のラジカルが付加した化合物やダイマーが生成することがわかった。そこで、アルコール溶媒中でヒドロキ
シマレイミドのイオン照射を行い、ＬＥＴ効果について検討する。

0.08
He 100MeV
0.06
0.04

C 220MeVHe 50MeV

0.02

Ne 350MeV

0
0

50

100

150

200

250

300

350

Differential G-value＜実験方法＞ ヒドロキシマレイミドを2-プロパノー
Incident energy of ion/MeV
ルおよびメタノールに溶かした（0.1モル％）試料に
Fig.1
Apparent G-value depending on the incident
原子力機構ＴＩＡＲＡ施設内ＡＶＦサイクロトンのＮ
energy of ion in 2-propanol.
ｅイオン(350 MeV)、Ｃイオン(220 MeV)およびＨｅイオン(100 MeV,50 MeV)を照射した。また、試料の上にLET eV/nm
1
10
100
1000
アルミ箔を置き、入射イオンのエネルギーを変化させ、
1
ＬＥＴ依存性を調べた。生成物およびヒドロキシマレ
イミドは、液体クロマトグラフ・質量分析計（カラム
He(100MeV)
ＯＤＳ、移動相アセトニトリル:水＝50：50、イオン
0.1
C(220MeV)
化法：ＥＳ-ＮＣＩ）で分析した。分析試料は、真空He(50MeV)
乾燥した残留物をアセトニトリルで溶解したものを用0.01
いた。
Ne(350MeV)

Differential G-value＜結果および考察＞ 吸収線量あたりのヒドロキシマ
0.001
レイミドの減少割合から分解効率を求めた。得られた分解効率をイオンの入射エネルギーあたりで規格化す
Fig.2 LET dependence of differential G-value obtained
ると、見かけのＧ値が得られる。Fig.1に2-プロパ
by ion irradiation in 2-propanol.
ノール中での分解での初期エネルギーに対する見かけのＧ値をプロットする。初期エネルギーの増加に伴い、LET eV/nm
1
10
100
1000
Ｇ値は増加した。これより、ＬＥＴの増加に伴い微分1
Ｇ値が減少すると推測される。これは、溶媒分子のラジカルなど、生成物の反応に関与する活性種の生成量
He(100MeV)のＬＥＴ依存性に対応すると考えられる。
0.1
アルミ箔によるＬＥＴ増加の各ステップで微分Ｇ値
C(220MeV)
He(50MeV)が一定と仮定して、見かけのＧ値から微分Ｇ値を概算した。2-プロパノールおよびメタノール中での照射で0.01得られた微分Ｇ値をFig.2-3に示す。Ｈｅイオン照射では、50MeVと100MeVで得られた微分Ｇ値はほぼ直線0.001関係にあるが、ＣイオンやＮｅイオンの重イオン照射で得られた値とずれている。Ｈｅイオン照射において、Fig.3 LET dependence of differential G-value obtained
イオン種効果があるものと考えられる。これは、メタ
by ion irradiation in methanol.
ノール溶媒中で、より明確に現れた。
今後は、添加物を入れた系で、活性種の生成機構とＬＥＴの関係について、γ線照射と比較して検討していく予定である。

－ 159 －

JAEA-Review 2007-060

4-18 Transient Absorption of a Cation Radical of Pyrene
Induced by Heavy Ion Beam Pulses
a)

a)

a)

a)

b)

T. Kondoh , J. Yang , K. Kan , Y. Yoshida , H. Shibata , M. Taguchi
a)

b)

c)

and T. Kojimac)c)ISIR, Osaka University, Faculty of Engineering, Kyoto University, Eenvironment andIndustrial Materials Research Division, QuBS, JAEA

The heavy ion beam is a high LET radiation. Ion beam can excite materials high densely. The characteristic of this ion
beam was used to develop the new technology such as the material and the medical application. Ion beam pulse radiolysis
is developing for elucidation of the initial process of ion beam induced chemical reaction. Our unique measurement method
is developing using a scintillator and the photon counting method. Transient optical absorption of the Pyrene’s cation radical
which was induced by irradiation of 220MeV C5+ ion was measured. A decay time of cation radical of pyrene in ion beamcase was faster than that in electron beam case.
導いた。シンチレーターはCaF2(Eu)(940 ns,435 nm)を用いた。イオンビームの効果を解明するために、電子線パルスラジオリシスも行い比較検討した。電子線照射と測定は阪大産研で行った。測定する波長領域で、吸収も発光もない塩化メチレンにピレンを溶解し、イ
オンビームが誘起した活性種をピレンの活性種として測定し時間挙動を調べた。
Fig.2に220 MeV C5+ イオン照射により誘起した100
mMピレン塩化メチレン溶液の440 nmでの過渡光吸収をElectron Beam

0.04
Ion
Electron（×0.07）

0.03

OPTICAL DENSITY

高速重イオンビームは高LET放射線であり、物質中を直進し一定の深さで大きなエネルギーを与えるので物質を局所的に高密度励起できる。イオンビームの特性を利用した新規プロセスを開発し、材料、医学等の領域へ応用されている。しかし、応用技術を発展させるにはイオンビームが誘起する化学反応の機構を明らかにする必要がある。イオンビームによって生成される短寿命活性種の挙動を明らかにし、イオンビーム初期過程を解明する。高密度励起効果は、活性種の分布や減衰過程に反映される。活性種が高密度にできるため、再結合や化学反応が、非常に短い時間領域で起こることが予測される。本研究では、イオンビームによる固体シンチレーター発光を分析光とすることにより高感度なフォトンカウンティング法と組み合わせて、
イオンビームの励起構造に適した過渡吸収実験を考案した。この方法では、イオンビームが通過した微小領域でのみ、分析光が発生し活性種が誘起され、過渡光吸収を測定できる。TIARAのパルス性能を活用した時
間分解分光法を開発し、ナノ・ピコ秒時間領域のイオ
ンビーム誘起反応初期過程の解明を行っている。
本研究の吸収分光測定システムをFig.1に示す。
本実験では、AVFサイクロトロンからの220 MeV C5+ イ
オンを用いた。ビームはチョッパーで間引かれ、イオ
ンビームは、金属箔窓と試料間に設置されたシンチ
レーターを通過し試料に入射した。シンチレーターの発光を分析光とし、光ファイバーを通して光測定系に

e-

＋

0.02
Heavy Ion Beam

0.01

e-

0

-0.01

＋

0

100
Time(ns)

200

ee-

＋

＋
e-

＋

High Densely Excitation

Fig.2 Transient Optical absorption of 100mM PyreneCH2Cl2 solution at 440nm induced by Ion beam (Graydots) and electron beam (Black triangle dots)
灰色ドットで示した。27 MeV電子線の場合を黒三角で示した。比較すると減衰特性に違いが見られた。電子線励起の場合長寿命成分があるのに対し、高速重イオ
ンビームでは、単純な指数関数減衰ではないが、簡単のために指数関数を仮定すると約85 nsの時定数で減衰した（黒実線）。電子線励起の場合に比べて明らかに速く減衰している。右に示したように、高速重イオ
ン励起では、ピレンカチオンラジカルと消滅する電子も同時に高密度に生成されるために、電子線励起の場
合と比較して短時間で消滅すると思われる。ピレン濃度依存性を1 mM,10 mM,100 mMで調べた。過渡吸収強度はピレン濃度に依存して増加したが、高濃度ではピレン濃度に単純比例しなかった。イオンビームが生成するピレンカチオンラジカル濃度の飽和が起こっている可能性がある。

Fig.1 Measurement system of ion beam induced
optical absorption－ 160 －

JAEA-Review 2007-060

4-19 Basic and Application Studies on Chemical Responses to
Quantum Beams in Heterogeneous Systems
a)

a)

a)

b)

R. Nagaishi , R. Yamada , N. Aoyagi and Y. Sugoa)b)

Division of Environment and Radiation Sciences, NSED, JAEA, Division of Fuels and Materials
Engineering, NSED, JAEA

(a)

50kGy
100kGy200kGyAbsorbance

0.6

Pt
2 element
supported

0.4

0.2

SiO2

4MGy, 0.4M H2SO4500

Pd supported
Rh supported
Pt supported

1

4asbestos, JAWE

10MGy, 17.8M H2SO4

water radiolysis

Al2O3 added

(b)

(a)
1000

900kGy0.8

Absorbance(b)

original
solution only

2-

Count, a.u.

PdCl 4oxide: 10 mg/mL
dose : 1.59 kGy

3

References
1) R. Nagaishi et al., Radiat. Phys. Chem. 75 (2006) 1051.
2) Y. Sugo et al., Radiat. Phys. Chem. 76 (2007) 794.
3) N. Aoyagi et al., Chem. Lett. 36(7) (2007) 890.

oxides3
chrysotile, Wako
2

2

[Pd(II)] 0=3.7mmol/L

1.0

Figure 1 shows the radiation-induced reductions involving
Pt-group elements. When considering the recover of
elements by using radiations, Pd(II), Rh(III) and Pt(IV) ionswere effectively reduced and solidified in the presence of asmall amount of oxide particles without using reducing
agents such as alcohol radicals, which can be formed byadding alcohols to the solution, although not in the absent(a); the solidified ones were dispersed on the particles andrecovered. When using the recovered particles, Ce(IV) ion
was reduced more effectively than the original ones.
Asbestos is discharged from general/industrial wastes inlarge amounts. Since it is so toxic due to its needle-shapeand to its resistance to heat and chemicals, a novel method
for the non-toxic treatment without using high-temperature
heat and harmful chemicals is expected. Figure 2 shows
results for asbestos irradiated in aqueous solutions. While thedried asbestos did not change before and after irradiated, itschange from needle- to particle-shape (a) and dissolution
into the solution rapidly proceeded with the increasing theabsorbed dose and acidity in the solution when it was
immersed into the solution. During the morphological, H2
gas was produced from the solution (b): the yield in thepresence of asbestos was much larger than those in theabsence of asbestos or in the presence of oxide particles 3).

H production / μM

From the standpoints of utilization of radioactive wastes,and of sophistication of separation process of spent fuels, wehave been investigating promotion or inhibition ofradiation-induced reactions in immiscible heterogeneous
systems: solutions coexisting/contacting with solid oxides,
solvent system with aqueous and organic phases, etc.. We
have recently report that the reactions of reduction of metal
ions and of hydrogen production in aqueous solution were
promoted by adding oxide particles to the solution 1), andthat the radiolysis of amides in n-dodecane was dependent
on aqueous solution contacting with the n-dodecane 2). In
this report, we illustrate recover of platinum-group elementsfrom aqueous solution, and non-toxic treatment of chrysotile
asbestos using ionizing radiations as the experimental results
found in fiscal 2006.
The samples of Pt-group element ions and asbestos were
irradiated at ambient temperature and pressure using theelectron beams (initial energies: 0.5-0.8 MeV) and γ-ray(avrg. one: 1.25 MeV) at JAEA-Takasaki: the dosimetry was
made by using the CTA-film and/or solution dosimeters.
After the irradiation, ions/molecules formed in the solution
part of sample were measured by using spectrophotometry,liquid chromatography and ICP-AES; the gas part such as H2
gas by using gas chromatography; the solid part such as
precipitates formed in solution or adsorbents on solid oxides
by using electron or X-ray spectrometry.
A large amounts of Pt-group elements, especially Pd, Re
and Ru, were contained in high level wastes discharged frompower reactors, and expected to be recovered from there.

1

blank, H2SO4

original
blank, water

0

300

400

500

Wavelength / nm

600

0
300

0
10

350

400

450

500

20

30

40

50

2θ, degree

60

70

0

0

50

100

Dose / kGy

Wavelength / nm

Fig. 1 The radiation-induced reductions involving Pt-group Fig. 2 Morphological change of needle-shaped asbestos andelements in aqueous solutions. (a) The recovering of
H2 production in aqueous solutions. (a) The XRD peak
Pd: when adding oxide particles adding to the solution,
at 24° indicating the crystalline asbestos decreased withPd(II) ion was effectively dispersed on the particles. (b)increasing the dose and acidity. (b) The yield of H2
produced in the presence of asbestos was much larger
When using the dispersed particles, Ce(IV) was reduced
more effectively than the original ones.
than those in the absence of asbestos or in the presenceof oxide particles.

－ 161 －

JAEA-Review 2007-060

4-20 Effect of Ion-irradiation and Annealing on Pinning
Property of PLD Prepared YBCO Tapes
K. Nakashima

a, b)

b)

b)

b)

b)

c)

, N. Chikumoto , A. Ibi , S. Miyata , Y. Yamada , T. Kubo ,c)c)A. Suzuki and T. Teraia)Department of Quantum Engineering and Systems Science, The University of Tokyo,c)Superconductivity Research Laboratory, ISTEC, Department of Nuclear Engineering andManagement, The University of Tokyob)

The change in pinning properties of YBCO tapes prepared by pulsed laser deposition (PLD) method was investigated after
ion-irradiation and thermal annealing treatment in order to confirm that ion-irradiation is effective for the Jc enhance in thepractical material. In this study, YBCO tapes (2 mm×2 mm×0.5 mm) were irradiated with 400 MeV Kr18+, 450 MeV Xe23+ or
500 MeV Au31+ from 1.0×1010 to 1.5×1012 ions/cm-2. As a result of ion-irradiation, the enhancement of Jc was observed
especially at high applied magnetic field in 77 K. After the ion-irradiation, the samples were annealed at the temperature of
473 K or 673 K in the oxygen atomosphere for 2 h. From the post –annealing experiment, it was clarified that oxygen
vacancies and interstitial atoms in the irradiated YBCO tapes can be recovered at the temperarure of 473 K and 673 K,
respectively.
のXe23+、500 MeVのAu31+を選択し、照射フルエンスは
1×1010 ～ 1.5×1012 [ions/cm2] の 範 囲 と し た 。 PPMS
（Quantum Design社製）を用いた磁化測定により、転移温度(Tc)、臨界電流密度(Jc)等の評価を照射前後で行った。照射後アニールは、照射試料を酸素雰囲気中
で目的の温度、時間で保持した後に銅板上で急冷しその影響を調べた。
温度77K、印加磁場2Tにおける照射フルエンスと Jcの 関 係 を Fig.1 に 示 す 。 ど の イ オ ン 種 で も 5 × 1011
[ions/cm2] 程度のフルエンスで最もJcが向上した。また、Jcが最も向上するイオン種はXeイオンであるが、この理由は結晶性を大きく損なわずに有効な円柱状欠陥を多数導入できるためであると考えられる。
照射後アニール実験は473Kおよび673Kについて2時間行った。473 Kでは酸素欠陥が、673 Kでは格子間原子が、それぞれ過剰フルエンス照射の場合に特に大きく回復することが分かった。
2.0E+05
Critical Current Density[A/cm2]

1986年に銅酸化物における高温超伝導が発見されて以来、液体窒素温度である77 Kにおける超伝導応用へ向けて種々の研究開発が行われている。HTSCは第2種超伝導体であるため、磁場中では量子化された磁束(Vortex)がHTSC内へ部分的に進入する。Vortexが超伝導電流により駆動されると電気抵抗が発生してしまうことから、Vortexをピン止めする必要が生じる。ピニ
ングセンターとなるものは超伝導体中の欠陥や不純物などであり、高い臨界電流密度（Jc）を実現することのできる効果的な導入方法の開発が進められている。
量子線照射は、製作過程によらず、照射条件を変化させることで超伝導体内のピニングセンターの形状・密度を制御できる利点がある。そこで本研究においては、
重イオンビーム照射を用い、現在開発が進められている超伝導線材であるPulsed laser deposition法（PLD法）により作成されたYBCO線材(Y系PLD線材)へ照射欠陥を導入し、Jcなどの超伝導特性の変化を調べた。
重イオン照射による欠陥は中心にアモルファス構造を有する円柱状となるが、その際、電子的阻止能 Se[KeV/Å]が大きいほど、欠陥の直径が大きくなることが報告されており 1) 、過剰フルエンス照射では欠陥が重なるために超伝導特性は低下してしまう。しかし、適当な熱アニールにより低下した特性が回復するという報告がなされている 2) 。以上のことから、本研究ではY系PLD線材に照射フルエンス、イオン種を変えた重イオンを照射し、超伝導特性の変化を調べると共に、照射後アニールを行い、アニールによる超伝導特性および結晶構造の変化を評価し、試料の特性向上条件を調べた。
照射用試料は(財)国際超電導産業技術研究センター
超電導工学研究所において作製されたY系超伝導線材を2 mm×2 mm×0.5 mm程度に切り出して作製した。高エネルギー重イオン照射にAVFサイクロトロンを使用した。照射は保護層であるAg層(5 μm)側からYBCO
層(0.5 μm)に垂直に照射した。照射イオン種はYBCO
層を貫通する条件として、400 MeVのKr18+、450 MeV

1.5E+05◇〇△□

1.0E+05

ion
Kr
Xe
Au
Au
(No Ag layer)

5.0E+04

0.0E+00
unirradiated1.0E+09

1.0E+101.0E+11
1.0E+12
Irradiation Fluence[ions/cm2]

1.0E+13

Fig.1 The relationship between fluence and Jc.
本研究の一部は超電導応用基盤技術開発業務の一環として新エネルギー・産業技術総合開発機構（NEDO）の委託により実施された。
References
1) Y. Zhu et al., Phys. Rev. B 48, 6436 (1993).
2) T. Terai et al., Physica C 282-287, 2285 (1997).

－ 162 －

JAEA-Review 2007-060

4-21 Damage Evaluation by Means of Electrical Resistivity
Measurement in Oxide Irradiated with MeV Electrons
a)

b)

c)

a)

a)

N. Ishikawa , S. Yamamoto , Y. Chimi , H. Sugai , T. Kato and A. Iwase
a)

d)

b)

Division of Fuels and Materials Engineering, NSED, JAEA Environment and Industrialc)Materials Research Division, QuBS, JAEA, LWR Long-term Reliability Research Unit, NSRC,d)
JAEA Department of Materials Science, Osaka Prefecture University
resistivity is found for both irradiations in contrast to themonotonic increase found for high-energy ion irradiations.
The decrease in electrical resistivity probably originatesfrom increase in carrier concentration which may be related
to displacements of oxygen atoms. For high fluence region(>1x1015 cm-2) the electrical resistivity can be described by
the linear function of the logarithm of fluence. In thisfluence range, the calculated atomic displacements are in theorder of ppm, and the mutual interaction between createddefects is not intense. Moreover, the change in mobility
due to increase in scattering center for conduction electrons
is probably very small.
The slopes of the curve shown in the figure are almost thesame, and the defect creation cross section for 2.5 MeV
electron irradiation is higher than for 1.0 MeV electron
irradiation, indicating that the energy increase contributes toenhancement of defect creation cross section.
The
investigation over wider energy range is necessary todescribe more precise energy dependence of the resistivity
behavior.

0

Δρ/ρο

One of the well-known standards for describing radiation
damage density in solids irradiated with high energy(keV-MeV) particles is called dpa (displacements per atom).
Radiation damage created by different radiation conditions
can be compared respectively with the common standard, if
dpa is adopted. Especially when the target material is a
simple metal, this evaluation method is widely used. Thisis because relatively simple defects are created in an
irradiated simple metal which consists of one atom species.
Moreover, elastic displacement is the only origin of thedefect formation for simple metal, and this facilitates theestimation of the dpa value.
However, it is not established for oxide ceramics
materials that this method can be simply applied for theestimation of damage density, and there is a significant
possibility that complicated defect formation or annihilation
can take place. Moreover, for oxide ceramics, the method
for experimentally evaluating radiation damage has to be
re-examined in the first place.
In this study electrical resistivity measurement is adopted
for evaluating radiation damage in oxides as it is widelyused for the evaluation of radiation damage in metals.
Electron irradiation of TiO2-x and in-situ electrical resistivity
measurement were performed.
The energy range isrestricted in the range of 1.0-2.5 MeV, since in this energy
range the irradiation with electrons is known to cause elastic
displacements of target atoms, and relatively simple defects
are created.
Thin films of TiO2-x were deposited on SrTiO3 (100)single crystal substrates, and were irradiated with 1.0 MeV
and 2.5 MeV electron beam. The thickness of the films
was about 0.3 μm which is thin enough for the electrons topass through. The irradiations were performed at room
temperature (280-283K), and the fluence dependence ofelectrical resistivity was measured in-situ at a fixed
temperature of 280K by means of the conventional four
probe method.
In Fig.1 the electrical resistivity as a function of fluence isshown for TiO2-x irradiated with 1.0 MeV and 2.5 MeV
electrons.
The monotonic decrease of the electrical–0.1○ 1.0MeV electron● 2.5MeV electron
–0.2
10

14

10

16

–2

Fluence (cm )Fig.1 Fluence dependence of the change in electricalresistivity normalized by the value before irradiation(Δρ/ρο) in TiO2-x irradiated with electrons. Closed circles
are the data for 2.5 MeV electron irradiation, and theopen circles are for 1.0 MeV electron irradiation.

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4-22 Lattice Defects Induced by Electron Irradiationin FeRh Alloys
a)

a)

a)

A. Iwase , A. Ishii , F. Hori , Y. Zushi

a)and N. Ishikawab)a)Department of Materials Science, Osaka Prefecture University,b)
Division of Fuels and Materials Engineering, NSED, JAEA

FeRh alloys were irradiated with 0.80 -MeV and 2.0 -MeV electrons, and the defect structure was studied by means of apositron annihilation technique. The experimental result shows that the electronic structure around irradiation-induced
vacancy-type defects depends on the energy of electrons.
こ の 欠 陥 量 は 照 射 量 か ら 計 算 さ れ る 値 が 1.95x10 17(0.8 MeV)、7.6x10 17 (2 MeV)程度である事を考えると妥当である。
一 方 で 導 入 さ れ た 欠 陥 の 形 態 を 考 え た 場 合 、 0.8
MeVと2 MeVではSの値がほぼ同じであるのに対し、W値が異なっている。このことはこの２つの照射で導入された空孔の周囲の電子状態に違いが生じた事を示す。すなわち、この合金系で考えられる空孔はFe空孔(V Fe )とRh空孔(V Rh )の２種類であり、照射によってV Fe とV Rh との濃度比に偏りが生じていると考えられる。これまでの結果と比較して考えると、2MeV照射では両空孔が均一に入るが0.8 MeVでは鉄原子のみが弾き出され、V Fe のみが照射によって導入された事を示している。

0.172
Fe
0.17

W-parameterFe-50%Rh は B2 構造を有する金属間化合物であり、室温付近で強磁性状態から反強磁性状態に磁気相転移を起こす合金である。最近我々は、この合金を高速重イオン照射することにより、本来反強磁性を示すべき低温でも、強磁性が発現することを、磁化測定で明らかにしてきた。イオン照射の場合は、ターゲット試料の原子に与えるエネルギーが大きいため、Fe 原子も Rh 原子も区別なく弾き出されてしまう。
これに対して、電子線照射はターゲット原子へ与えるエネルギー値が弾き出しエネルギーと近いため、電子線のエネルギーを選ぶことによって、Fe 原子のみを弾き出したり、Fe 原子、Rh 原子とも弾き出したりすることができる。従って、電子線照射を用いて、Fe 原子のみを弾き出した場合と Rh 原子も同時に弾き出した場合に、試料中に生ずる格子欠陥,、あるいは磁性状態がどのように違うか、という点が興味深い。以前の実験により、電子線のエネルギーが0.5 MeV 以下のときは Fe 原子、Rh 原子とも弾き出しは起こらず、0.5-1.0 MeV の時には、Fe 原子だけが弾き出され、エネルギーが 1.0 MeV を超えると、
Fe 原子に加えて Rh 原子の弾き出しも起こる、とい
うことがわかっている。そこで、TIARA シングルエンド加速器により Fe-50%Rh に 0.8 MeV, 2.0 MeV の電子線を照射し、陽電子消滅法によって試料中の格子欠陥を調べた。
試料は Fe-50%Rh のインゴットから切り出し熱処理を行った。照射条件は上で述べた通りである。陽
電子消滅測定は全て室温で陽電子寿命とドップラー
拡がり測定を行った。
Fig.１に陽電子消滅同時計数ドップラー拡がり測定から得られたS-Wパラメータの相関図を示す。一般にSパラメータの変化は空孔の濃度およびサイズに依存し、Wパラメータの変化は陽電子消滅位置周囲の原子種に反映される。そのため、この図から横軸の変化から電子線照射により0.8、2 MeVいずれの場合も空孔型欠陥が導入された事がわかる。陽電子の金属結晶中での消滅が飽和するのはおよそ100at.ppm程度であることを考えると、未照射での空孔型欠陥量は数〜数10 ppm程度で、照射によって〜
100 ppm程度に増加している事がわかる。

0.168
Fe50Rh
0.166

0.8MeV irrad.
0.164

2MeV irrad.
0.162
0.476

0.478

0.48

0.482

0.484

0.486

S-parameter

Fig. １ Relationship between S-parameter andW-parameter for FeRh alloys irradiated with 0.8
MeV electrons and 2 MeV electrons. Data for pure
Fe and unirradiated Fe-50Rh alloy are also shownin the figure.

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JAEA-Review 2007-060

4-23 Study of Mass-transport Process in Noncrystalline Films
Using Ion Beam Technique
a)

a)

a)

a, b)

c)

c)

H. Naramoto , K. Narumi , S. Sakai , Y. Maeda, T. Motooka , Y. Ikoma ,c)c)S. Munetoh and X-q. Chenga)b)

Advanced Science Research Center, JAEA, Faculty of Engineering, Kyoto University,c)
Department of Materials Science, Kyusyu University

The noncrystalline layers were prepared with aconventional evaporation technique using Knudsen cells bykeeping the exact stoichiometry of Co4C60 mixture because
the Co-C60 mixtures can be easily phase-separated above thestoichiometric ratio3, 4). The Ag top layer was deposited to
avoid the influence of oxygen attack on the transport of Co
atoms in the Co4C60 mixture. The mass-transport features
were characterized in-situ by Rutherford Backscattering
Spectrometry (RBS) equipped with a heating stage under
the ultra high vacuum.
The amorphization of Si was induced by 200keV Ar ion
irradiation up to the appreciable dose of 2×1016/cm2 to
RBS. The additional irradiation with 10keV Ar+ ions was
performed to introduce the possible bending strain in thenear surface region by changing the doses systematically.
Figure 1 illustrates the typical profile changes of thelayered films characterized by 2MeV 4He+ RBS. Afterannealing at 397K, there induced the considerable profilechanges at the Ag top layer and also at the Co4C60 mixture
layer. The temperature range observed coincides with that inwhich the compound is relaxed into more stable form as
evidenced by the detailed Raman analysis4). Further
annealing at 483K induced the definite change of Co profile
moving toward deeper. This result is totally different fromthat caused by the thermal diffusion with the broadening
nature towards both sides. The inward change of Co atoms
could be associated with the peculiar nano-structure together

Ag(40nm)/C60(100nm)/Co4C60(30nm)/C60(100nm)/MgO(100)Scattered Yield (Counts)

The energetic ions have been employed for the
position-sensitive materials processing and also for thedepth-sensitive analysis of elements and defects1). Thesefeatures are typically suitable for the study of atomistic masstransport process in the near surface region, which can not
be complemented by other techniques.
The mass-transport processes in crystalline solids aremostly initiated through the thermal activation of therelevant atoms bound to the surrounding atoms with theperiodicnature.
The
recentprogressinnanoscience/nanotechnology has opened the new interests inthe transport process in the noncrystalline and/or the
inhomogeneous atomistic environment2).
In the present report, two kinds of mass-transport related
studies are described on the noncrystalline layer ofAg(40nm)/C60(100nm)/Co4C60(40nm)/C60(100nm)
on
MgO(100) substrate, and on ion-irradiation-amorphized Si.

: 483K, 1Hour: 393K, 1Hour: before annealing

1000

Co

100
10
1
100

Ag

200

300
400
500
Channel Number

600

Fig. 1 2MeV 4He+ ion RBS spectra from the multi-layer of
Ag/C60/Co4C60/C60/MgO(100) annealed in the temperature
range between 300K and 483K.
with the possible bending strains.
The effect of strain on the implanted Ar distribution in
amorphized Si was examined by implanting the 10keV Ar
ions additionally. In this case, the compressive strains canbe induced in the amorphized region below the surface.
The results obtained are not shown here for the simplicity,
but the conclusions are listed below.
*The transportation of implanted 200keV Ar atoms toward
the surface region was observed clearly at the higher dose of
10keV Ar ions more than 5×1016/cm2.
*The influence seems to be localized in the shallower region
than the peak depth of implanted profile.
*The redistribution of implanted Ar atoms does not induce
the crystallization of amorphized region.
*The systematic analysis on the observed phenomena is inprogress by changing the strain parameters and theimplanted species.
References
1) H. Naramoto et al., Nucl. Instr. & Meth. 161 (2000) 534.
2) M. J. Demkowicz and A. S. Argon, Phys. Rev. B 72
(2005) 245205.
3) S. Sakai et al., Mater. Trans. 46 (2005) 765.
4) S. Sakai et al., Thin Solid Films 515 (2007) 7758.
5) V. Lavrentiev et al., Chem. Phys. Lett. 423 (2006) 366.

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JAEA-Review 2007-060

4-24 Carbon-concentration Analysis of Si Surfaces
Bombarded with 10- to 100-keV C60 Ionsa)K. Narumi , H. Naramotoa)a)and Y. Maeda

a, b)

b)

Advanced Science Research Center, JAEA, Department of Energy Science and Technology,
Kyoto University,

Unirrdiated
8.7×1014 C60/cm2

×50

2

1

0
0

1

3

from the ion fluence. The experimental results areinconsistent with this line: At lower fluence, measured
carbon concentration is higher than the value estimated fromthe ion fluence, while at higher fluence the increase rate ofcarbon concentration decreases.
The former could be
attributed
tocarbonimplantationby
C60-bombardment-induced
recoilofthesurfacecontaminants. On the other hand, the latter reflects thestrong sputtering effect of the C60 bombardment. Thisconclusion can be explained by the following scenario: The
carbon concentration in the surface layer is determined by
the competition between the sputtering and the carbon
deposition or implantation by the C60 bombardment.
Under this competition, the higher the carbon concentration,
the more carbon atoms are sputtered; thus, the increase rateof the concentration decreases with the ion fluence. It
could be expected that the carbon concentration reach acertain value determined by the sputtering yield.
References
1) H. Naramoto et al. TIARA Annual Report 2002,
JAERI-Review 2003-033 (2003) 225.
2) H. Naramoto et al. TIARA Annual Report 2003,
JAERI-Review 2004-025 (2004) 211.
3) H. Naramoto et al. TIARA Annual Report 2004,
JAEA-Review 2005-001 (2006) 271.
4) H. Naramoto et al. Takasaki Aannual Report 2005,
JAEA-Review 2006-042 (2007) 149.
5) E. Kashy et al. Phys. Rev. 117 (1960) 1289.
[×10 ] 4
16

Carbon Concentration (/cm 2)

Yield (arb. units)

Our previous study shows that sputtering is one of themost important radiation effects of 10-to-100-keV C60
ions1-4). It is so strong that it can affect any other radiation
effect of C60 ions. Carbon deposition or implantation by
C60 irradiation is one of such effects. Carbon content in
the surface layer is sensitive to the sputtering; thus, analysis
of carbon concentration could be helpful to understand thestrong sputtering effect of C60 irradiation. We will report
here the analysis of carbon concentration of Si surfaces
bombarded with 10-, 50- and 400-keV C60 ions.
A piece cut from a Si(100) wafer was irradiated with C60
ions. Before the irradiation, the samples were cleaned witha wet chemical treatment to reduce carbon contaminants on
the surface. A part of the sample was covered with a mask,so that one sample had both irradiated and unirradiated areas.
After the C60 bombardment, carbon concentration in thesurface layer was evaluated with a nuclear reaction 12C(d,p)13C using 1.2-MeV D. Examples of the observed energy
spectra are shown in Fig. 1. Signals at lower energies
correspond to the primary D scattered from Si nuclei, while
those at higher energies are attributed to protons produced in
the nuclear reaction. Integrated proton yields reflect
overall carbon content in the surface layer. Since theproton signals in the spectrum for an unirradiated area
originates from residual carbon contaminants on the sample,
the difference between the proton yields of bombarded andunirradiated areas is caused by the C60-ion bombardment.
Figure 2 shows the fluence dependence of the carbon
concentration in the surface layer of C60-bombarded Si.
The number of 12C nuclei per cm2 was evaluated with theuse of the cross section measured by Kashy et al.5) A solidline in the figure shows carbon concentration estimated[×104] 3

3

2

1

0 11
10

3.2

Energy (MeV)

400 keV C602+
2+
400 keV C60+
50 keV C60
10 keV C60+

1012

1013

1014

1015

1016

2

Ion Fluence (C 60/cm )Fig.1 Example of energy spectra measured when 1.2-MeV
D was incident on a Si sample bombarded with 50-keV
C60+ ions.
Energy spectrum measured on an
unirradiated part of the sample is also shown.

Fig.2 Fluence dependence of the carbon concentration at
Si surfaces bombarded with 10-, 50- and 400-keV C60
ions. Solid line shows areal density which is 60
times as much as C60 ion fluence.

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JAEA-Review 2007-060

4-25 1-D Crosslinked Polymer Nanowires Prepared by Single
Particle Nanofabrication Techniques
a)

b)

b)

b)

b)

S. Seki , M. Sugimoto , T. Sato , M. Oikawa and T. Sakai ,a)Graduate School of Engineering, Osaka University
Quantum Beam Science Directorate, Japan Atomic Energy Agency

b)

(a)

(b)

200 nmHeight (nm)Recently we have successfully produced 1-D nanowiresby the crosslinking reactions of polymer molecules within
an ion track along the particle trajectory. The present
nano-scaled negative tone imaging technique (single particle
nano-fabrication technique: SPNT) shows a striking contrast
to the conventional nuclear track technique, providing thedirect formation of nanowires based on a variety ofpolymeric materials with fairly controlled sizes. Effective
crosslinking reactions of the polymers are the uniquerequirement of SPNT. Thus nanowires reflecting theproperties of the target polymer materials have beensuccessfully realized by the simple one-step procedure of
SPNT, giving conducting, light-emitting, ceramic, protein,hydrogel nanowires as well as the multi-functional
nanowires /nanoparticles by the combination of the polymer
materials. The formation process of ultra-fine opticalnano-fibers by SPNT is discussed in the present letter basedon silsesquioxanes (SSQ) as the target polymer material
which is optically clear and suitable to the organic-inorganic
conversion reactions by subsequent sintering processes.
High energy particle beam at low fluence without
overlapping ion tracks produces single-ion events in thetarget materials, yielding a cylinder-like nanofiber in thethin film. Fig. 1 shows the AFM images of the SSQ
nanofiber observed on Si substrates. The nanowires wereclearly produced by all high energy particles used, and thethickness of the cross-section depends strongly on theparameters of the incident particles. The relationshipbetween radial distribution of deposited energy released byan incident particle and induced crosslinks of polymer
molecules has been precisely investigated in the previous
studies, resulting in the changes of the radius of crosssection of the cylindrical nanofiber. The radial distribution
was characterized by the linear energy transfer (LET) of theincident particle which reflects the averaged energy density
per unit length in a particle trajectory. The initial radial
distribution of the released energy and the subsequent radial
diffusion of the energy and/or reactive intermediates
determine the cylinder-like area where gelation occurs, thus
the size increased considerably with an increase in LET ofthe particles. Radii of the cross-section of the nanofibers
were measured as 10.1, 8.7, and 6.3 nm, respectively underirradiation of 450 MeV Xe, 400 MeV Kr, and 388 MeV Ni
ion beams. The values of LET of these particles arecalculated as 4800, 2700, and 1800 eV/nm, respectively in
SSQ thin films,13 which shows a striking coincidence withthe values of radii. In spite of the relatively small molecularweight of SSQ (Mw = 1.2 ×103), the thicker nanofibers in

(c)

10
0
0

50

x (nm)

100

150

Fig. 1. AFM micrographs of nanofibers based on SSQ produced
by SPNT. Images (a) – (c) were observed in the thin films of
SSQ at 300 nm thick after irradiation of 450 MeV Xe, 400 MeV
Kr, and 388 MeV Ni ion beams at the fluence of 2.9×109 ions
cm-2(a,b) or 1.1×1010 ions cm-2 (c), respectively. Superimposed
figure is the profile of cross section of a nanowire at the point
represented by an arrow in (a).

comparison with the size observed for the other polymericmaterials were observed. It has been already revealed thatthe radial size of the cylinder-like area depends also on theefficiency of the crosslinking reaction (G(x)). The vinylgroups in the side chain promote efficiently the crosslinking
reactions, and this is the case giving considerable increase in
the radius of nanofiber based on SSQ. The nanofibers basedon the other silsesquioxanes were also successfully preparedby the same scheme. Sintering of the nanofibers at 1000 K
caused no change in the number density of the nanofibers
based on all the polymeric materials. The shrinking of thesizes was observed for the nanofibers giving 30-40 %reduction in the radii, however there was almost no change
in the length of the nanofibers. The interaction at theinterface restricts the axial shrinking, hence radial shrinking
dominates in the present case. The successfulorganic–inorganic conversion by this sintering processprovides the ultrafine SiO2 optical nanofibers as
demonstrated in the present study.
References
1) S. Seki, et al., Adv. Mater.,13 (2001) 1663.
2) S. Seki, et al., J. Phys. Chem. B, 103 (1999) 3043.
3) S. Seki, et al., Macromolecules, 38 (2005) 10164.
4) S. Tsukuda, et al, J. Phys. Chem. B, 110 (2006) 19319.
5) S. Seki, et al., Macromolecules, 39 (2006) 7446.
6) S. Tsukuda, et al., Appl. Phys. Lett., 87 (2005) 233119.
7) S. Seki, S. Tagawa, Polymer J., 39 (2007) 277.

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JAEA-Review 2007-060

4-26 Analysis of Light Elements in Carbon Materials
a)

a)

a)

b)

b)

Y. Horino , Y. Mokuno , A. Chayahara , H. Yasui , K. Awazu ,c)d)d)S. Yamamoto , K. Narumi and H. Naramotoa)National Institute of Advanced Industrial Science and Technologyb)Industrial Research Institute of Ishikawac)Environment and Industrial Materials Research Division, QuBS, JAEAd)Advanced Science Research Center, JAEA
Carbon materials are well known for their excellent properties and many applications are being under intense study. The
plasma enhanced chemical vapor deposition (PECVD) using hydrocarbon gas is the most used method to synthesize carbon
materials. But hydrogen will be involved during processing and they will influence properties of carbon materials. In order
to investigate the influences, we examine the distribution of hydrogen at near surface region in some carbon materials by anuclear reaction analysis (NRA). We have checked the system by using a hydrogen-implanted silicon wafer. We could
obtain a profile of the implanted hydrogen which was consistent with one calculated with the TRIM code. It was found thatthe amount of hydrogen in poly-type diamonds was 0.2-1 at %. However, it was difficult to determine the amount ofhydrogen in single crystal diamonds due to a poor S/N ratio of the analyzing system.

YIELDS (counts/channel)

Siの場合、表面吸着水素と注入水素の分布が明瞭に
ダイヤモンドなどの炭素系薄膜材料が、炭化水素系
分かり、TRIMで計算した飛程44 nmとほぼ一致した。
のガスを用いた気相合成で作製された場合、水素が含
ダイヤモンドの場合も表面での水素の吸着が観察され有され 1,2） 、材料特性に影響する。そのため、水素のた。そのため表面の影響を受けないように、入射プ量・分布を評価することは炭素系新奇材料の創製･利
ローブのエネルギーを選んで、いくつかのダイヤモン
用に不可欠なものとなっている。しかし、特に数十ppmオーダーの微量の水素の定量分析は非常に困難で、 ド中の水素量の分析を行った。多結晶ダイヤモンドの場合、水素量は約0.2～1at%となり、製造方法により材料特性に対する影響の詳細な研究は行われていない
ばらつきが見られた。一方、単結晶ダイヤモンドの場のが現状である。
合、測定限界以下で定量は困難であった。S/N比を向本研究では、炭素系材料に対する水素の影響を検証上することが必要であり、現時点で、使用した分析シするために、炭素系薄膜材料中の水素分布を定量的に測定し、材料特性との関連を調べることを目的とする。 ステムの定量限界は100 ppmオーダーであることが分かった。
そのため、エネルギー6～8 MeVの15N（窒素同位体）と水素との共鳴核反応法（NRA）を利用した。水素分布を定量的に測定し、本方法の定量下限や深さ分解能を10000評価する。また、水素の吸着量や深さ分布と材料特性
Si(5E15)との関連を明らかにする。
POLY Diamond-TG
1
15
12
Diamond-2
測定に用いた共鳴核反応は、 H( N,αγ) Cで、共1000
鳴エネルギー（ER）=6.385 MeV、共鳴幅＝1.8 keVで15ある。試料に入射したプローブイオン（ N）が試料中でエネルギーを失いながら進行し、エネルギーがERに100
なると水素との核反応が起こり、約4.4MeVのガンマ線が放出される。エネルギー損失量が水素の存在する深さ、検出されるガンマ線が水素量の情報を有し、プ
10
ローブイオンのエネルギーをスキャンすることで深さ
6.4
6.5
6.6
6.7
6.8
方向の水素分布を得ることができる。共鳴幅が非常にPROBE ENERGY (MeV)
狭いため、深さの分解能は主に15Nイオンのエネルギー
Fig.1 Hydrogen profiles measured by the NRA. The
拡がりで決まり、今回は約5nmであった。
15
samples were a silicon wafer implanted with 2-keV H with
Fig.1 に 、 Si ウ ェ ハ に 2 keV H イ オ ン を 5 × 10
2
a dose of 5×1015ions/cm2 (■), a polycrystalline diamondions/cm 注入したもの（■）、多結晶ダイヤモンド(▲) and a single-crystalline diamond (○).
（▲）、およびダイヤモンド単結晶（○）を分析した
結果を示す。いずれの場合も約6.49 MeV近傍にピーク
Referencesが観察された。これらは材料表面に吸着している水素
1) Y. Horino, et al., New Diamond and Frontier Carbonに相当する。図中のエネルギーは使用した加速器の表Technology 16 (2006) 63-69.
示をそのまま用いている。そのため実際のエネルギー
2) Y. Mokuno, et al., Diamond and Related Materials 15
より数10 keV程度のずれがある。
(2006) 455-459.

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JAEA-Review 2007-060

4-27 Structural Change in Si Induced by Ion Bombardments
and Its Application for Nano-Fabrication
a)

a)

a)

a)

b)

b)

T. Motooka , Y. Ikoma , S. Munetoh , X.Q. Cheng , H. Naramoto , K. Narumi ,b)b, c)S. Sakai and Y. Maedaa)b)

Department of Materials Science, Kyusyu University, Advanced Science Research Center,c)
JAEA, Faculty of Engineering, Kyoto University,

Energetic ion bombardments can induce various kinds ofeffects on inorganic crystalline materials through theelectronic excitations and nuclear collisions depending on
the incident ion energies. The electronic excitations along asingle ion passage can generate a heat pulse which results inthe shear stress extending to the surface. The nuclear
collisions can be influential through the generation of point
defects and the associated directional flow. This process canbe also employed to change the shape of the relevantsamples.
In the present study, the main concern has been focusedon the structural change in silicon. For the possible
applications for nanopore devices 1), silicon-on-insulator(SOI) samples with μm-size holes made byfocused-ion-beam (FIB) irradiation were prepared for theirradiation experiment. Through this experiment, theirradiation chamber was kept to be free from the carbon
contamination by cooled shrouds surrounding the samples.
Ar+ and Si+ ions were chosen to avoid the chemical
influences on the irradiation effects. The incident ion
energies are high enough to generate the displaced atoms.
Figures 1 and 2 show the transmission electron
microscopy (TEM) photographs obtained from the SOI
samples before and after the ion irradiation. The structuralchanges induced by ion bombardments were analyzed basedon the dark field (DF) and bright field (BF) images
combined with the selected area diffraction (SAD) patterns.
The shape of each hole was determined by using the BF
image, while the Si crystallinity of the hole region was
judged by the DF image using the Si(004) diffraction spot
and by using the SAD patterns with the resolution of
approximately 500 nm. Main results are summarized asfollows:
1)In the case of the irregular shaped hole (see Fig. 1), Si
looks to be damaged before ion irradiation probably due tothe FIB process, and no remarkable ion-bombardment
effects can be observed.
2) In the case of the round hole (see Fig. 2), the hole regionis crystalline before ion irradiation, but after ion irradiation
the hole region is changed to amorphous resulting in an
approximately 10 % reduction of the hole size.
3)The observed shrinking effect may be attributed todilation of crystalline Si upon amorphization induced by ion
beam bombardments.
Further studies on the ion-beam-induced shrinking effectsof the holes as well as a new method to form nanopores on
SOI 2) are currently underway.
References
1) C. Dekker, Nature Nanotechnology, (2007)209.
2) Y Ikoma et al., abstract of the 6th International
Conference on Thin Film Physics and Application(TFPA2007) (Sept. 25-28, 2007, Shanghai, China), p. 27(2007).

Fig. 1: TEM photographs from the SOI sample with airregular hole before and after irradiation with 3.5×1016/
cm-2 10 keV 40Ar+ ions.
Fig. 2: TEM photographs from the SOI sample with around hole before and after the irradiation with 3.0×
1016 /cm-2 10keV.28Si+ ions.

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JAEA-Review 2007-060

4-28 Ion-induced Self-organized Ripple Patterns on Graphite
and Diamond Surfaces
a)

a)

a)

b)

c)

K. Takahiro , K. Ozaki , K. Kawatsura , S. Nagata , S. Yamamoto , K. Narumid)and H. Naramotod)a)

Department of Chemistry and Materials Technology, Kyoto Institute of Technology,c)Institute for Materials Research, Tohoku University, Environment and Industrial Materid)als Research Division, QuBS, JAEA, Advanced Science Research Center, JAEAb)

The irradiation with heavy ions leads to various
morphological evolutions of material surfaces as a result ofa balance between roughening and smoothing processes. It
is known that self-organized ripple patterns are formed on
the surfaces in the case of off-normal incidence of ions. We
concentrate on the study of ripple formation on surfaces ofcarbon allotropes after irradiation under identical conditions.
According to the linear erosion theory developed by Bradleyand Harper1), similar features should be observed for all
different carbon materials since all surfaces become
amorphous already after low fluence irradiation. Veryrecently, Takahiro et al.2) experimentally showed thatdifferent features appeared on graphite, diamond andamorphous carbon surfaces. In the present work, highlyoriented pyrolytic graphite (HOPG) and single crystalline
diamond were irradiated under identical conditions in order
to investigate the allotropic effect on ripple patternformation.
The HOPG (0001) sample (1×1×0.1 cm3 in size),manufactured by Molecular Device Tools for Nano
Technology, Russia, was cleaved with a Scotch tape justbefore irradiation. The diamond (001) sample (0.3×0.3×0.05
cm3 ) is a commercially available Ib-type diamond. The
samples were irradiated with Xe + ions of 5–30 keV at
an incident angle of 60° with respect to the sample normal atroom temperature. The ion current density and ion fluence
were 2–4 μA·cm−2 and 2×1017 Xe+·cm−2, respectively. The
surface topography of the eroded sample surfaces was

References
1) R. M. Bradley and J. M. E. Harper, J. Vac. Sci. Technol.
A 6 (1988) 2390.
2) K. Takahiro et al., Nucl. Instr. Meth. B 256 (2007) 378.

ion beam
Intensity (arb. unit)

ion beamexamined with an atomic force microscope (AFM) in acontact mode. Raman spectroscopy was performed bybackscattering from the sample using an Ar laser operating
at 514.5 nm.
Figures. 1 (a) and (b) show AFM images taken for HOPG
and diamond irradiated with 30-keV Xe+. Ripples areclearly seen on the irradiated HOPG and diamond surfaces,
and they are aligned perpendicular to the ion-beamprojection. The averaged ripple spacing for HOPG is foundto be approximately 170 nm, much larger than that for
diamond (100 nm). The line profile analysis reveals that theamplitudes of ripples, defined as height differences between
hills and valleys, are typically 60 nm and 30 nm for HOPG
and diamond, respectively. Thus, large differences in ripple
wavelength and amplitude between HOPG and diamondwere recognized. The top surface layers of Xe+-irradiated
HOPG become amorphous as shown in Fig. 2. The SRIM
simulation predicts that the crystalline diamond surface istransformed into amorphous due to sputter erosion. Further
experiments under various irradiation conditions will reveal
more detail in the mechanism for rippling of carbon
materials. Such experiments are now in progress(a) HOPG(b) Diamond

30 keV-Xe-irradiated10 keV-Xe-irradiatedUnirradiated

800

1000

1200

1400

1600

1800

2000

-1

Raman Shift (cm )Fig. 1 AFM images (upper panels) of (a) HOPG and (b)diamond irradiated with 30-keV Xe ions at 60° to
2×1017 cm−2. Cross sectional line profiles (lower
panels) are also shown. Arrows indicate the projection of ion-beam direction.

Fig. 2 Raman spectra of HOPG before (bottom) andafter irradiation with 30-keV (top) and 10-keV(intermediate) Xe ions to a fluence of 2×1017 cm−2
at an incident angle of 60° with respect to thesample normal.

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JAEA-Review 2007-060

4-29 Optical Property Modifications of Diamond andSapphire by Ion Implantation and Heat Treatmenta)a)

Jae-Won Park , Hyung-jin Kim , Dong-Hwa Oha)b)

and Young-Chool Kim

b)

c)

c)

Korea Atomic Energy Research Institute, Sung Kyun Kwan University, Hanmi G. I. Laboratory

Results and discussion
The N-ion-implanted diamond showed only black evenafter post-implantation annealing, but the diamond
implanted with proton (H + ion) and subsequentannealing at 600 ℃ in vacuum emittedthepurple-red color.

(a)(b)
Fig. 1. The band gap of N-doped diamond is reduced by
1.12 eV as compared to the band gap of the clean
diamond (a), but the band gap of H-doped diamond isreduced by 1.96 eV (b).

Co 2p XPS peak 782.2 eV(CoAl2O4)

2400
2200
2000

250nm sputtering
350nm sputtering

780.6 eV(Co3O4)
778.7 eV(metallic Co)

1800
1600
1400
1200
1000
Co 2p3/2

800

810 805 800 795 790 785 780 775 770

Binding Energy (eV)Intensities (a. u cps)

Experimentals
100 keV Co and B ions using 400 keV ion accelerator
and 1 MeV H ions using 3 MV Tandem accelerator
were implanted into the sapphire and diamond samples
with a dose of about 10 17 ions /cm 2 for all samples,
followed by post-irradiation annealing at 600 ℃ –1200 ℃ both in air and in vacuum atmosphere for 2 ~24 hours. Once certain modifications in the opticalproperties of the treated diamond and sapphire
specimens were visually observed, the relevant samples
were analyzed with X-ray photoelectron spectroscopy(XPS) and FTIR to understand the mechanisms of themodifications. In order to examine the band gap
variation in the doped diamond and sapphire,calculations by first-principles density-functional
theory (DFT) were done 1) .

Since the DFT calculation shows a significant
difference in the band gap between N and H doped
diamonds (Fig. 1), the different elemental doping
should play a major role in the optical property change.
The transparent sapphire implanted with Co ionsshows sky-blue colors after post-implantation annealing
at 900 ℃ in air for 6 hours. XPS analysis shows that.
Co2p peak at 778.7 eV 2) which denotes metallic Co isclearly seen along with Co-Al-O peak at 782.2 eV 2) inthe as-implanted sapphire (Fig. 2a) while the peakcorresponding to metallic Co disappeared in the
post-implantation annealed sample (Fig. 2b). Therefore,
it can be concluded that the formation of Al-Co-O
compound is responsible for the sky-blue color
emission. On the other hand, the sapphire implantedwith H, B, N showed nothing but black or white evenafter annealing at 900 ℃.
Intensities (a. u cps)

Introduction
In order to modify the optical properties of sapphireanddiamondmaterials,amethodoftheion-implantation and subsequent annealing was
employed. To understand the change in opticalproperties, calculation of the band structure using
density functional theory (DFT) and characterizationsof surface chemical properties before and after the ion
implantation and subsequent annealing were conducted.

1800

Co 2p XPS peak 783.6 eV

1600
1400
1200

250nm sputtering
350nm sputtering

778.6 eV

1000
800
600
400
200
0

810 805 800 795 790 785 780 775 770

Binding Energy (eV)(a)(b)
Fig.2. Co2p XPS peaks obtained fromas-implanted(a)andpost-implantation
annealed (b) sapphire samples.

FTIR spectra for the sky-blue colored sapphire
implanted with Co ions followed by annealing show
broad absorption band in the range of 588 nm to 626
nm wavelength which seems to be affected by Co ion
implantation.
References
1) J. Y. Lee, J. Park, and J. H. Cho, Appl. Phys.
Lett.
87, 011904 (2005)
2) Haifeng Xiong, Yuhua Zhang, Kongyong Liew,
Jinlin Li, Journal of Molecular Catalysis A: Chemical
231, 145–151 (2005)－ 171 －

JAEA-Review 2007-060

4-30 Change in Curie Temperature in Fe-Ni and Fe-Ni-Mn
Alloy Thin Films Irradiated with Energetic Ionsa)b)

Y. Chimi , N. Ishikawa , A. Iwasec)and F. Ono

a)

d)

b)

LWR Long-term Reliability Research Unit, NSRC, JAEA, Division of Fuels and Materialsc)Engineering, NSED, JAEA, Department of Materials Science, Osaka Prefecture University,d)Department of Physics, Okayama University
irradiations are plotted against the total energy deposited by
the elastic displacement, Φ×Sn, where Φ is the incident ion
fluence, and Sn the nuclear stopping power for the incident
ion. This result implies that the density of the elastic energy
deposition is a dominant irradiation parameter for theincrease in TC in Fe-Ni alloy. In the case of Fe-Ni-Mn alloy,
the modification seems to be more susceptible to the elastic
energy deposition than that for Fe-Ni alloy.

Change in Curie temperature, ΔTC ( deg. )References
1) F. Ono et al., Nucl. Instr. and Meth. B 206 (2003) 295.
2) F. Ono et al., Mater. Res. Soc. Symp. Proc. 792 (2004)
441.
3) Y. Chimi et al., Nucl. Instr. and Meth. B 257 (2007)388.

(a) Fe–Ni

200

1

H ( 1.0 MeV )He ( 1.5 MeV )C ( 5.0 MeV )35
Cl ( 12.0 MeV )197
Au ( ~18–21 MeV )197
Au ( 200 MeV )
4

12

150
100
50
0
–4
10

–3

10

–2

10

–1

10

0

10

Energy deposited by elastic displacement, Φ × Sn ( keV/nm )3

Change in Curie temperature, ΔTC ( deg. )We have studied effects of high-energy heavy-ion
irradiation on the magnetic properties in Fe-Ni invar alloys,
and have already found that TC increases by theirradiation1,2). This result suggests that the local
ferromagnetic regions can be induced by the irradiation in
the paramagnetic phase above TC for the matrix of Fe-Ni
invar alloy. In general, high-energy heavy-ion irradiation ofmaterials induces electronic excitation continuously alongwith the ion path. The induced ferromagnetic region in theirradiated Fe-Ni alloy, therefore, may have linear shape.
However, it still remains uncertain whether the origin of theeffect is electronic excitation or elastic displacement,
because in our previous study1,2) we used bulk specimen inwhich the energy of the incident ions decreased with thedepth. In the present work, we investigate the change in TC
in Fe-Ni3) and Fe-Ni-Mn alloy thin films irradiated withseveral kinds of energetic ions and the dominant irradiation
parameter for the modification.
Specimens of Fe-Ni and Fe-Ni-Mn alloy thin films (~500
nm in thickness) were prepared on MgO(100) single crystal
substrates by means of rf magnetron sputtering at ambient
temperature with target materials of Fe-32at.%Ni andFe-28at.%Ni-7at.%Mn alloys, respectively. The specimens
were annealed at 1273 K for 1 h in a vacuum below~3.5×10-4 Pa. After this thermal treatment, the crystal
structure of the Fe-Ni specimen changed from bcc to fcc,
which was the same structure as the bulk material of Fe-Ni
invar alloy. The specimens were irradiated at room
temperature with 1.0-MeV 1H, 1.5-MeV 4He, 5.0-MeV 12C
and 12.0-MeV 35Cl ions by using the 3-MV tandem
accelerator of TIARA at JAEA-Takasaki, and 200-MeV
197
Au ions by using the 20-MV tandem accelerator at
JAEA-Tokai. In order to detect the irradiation effectprecisely, a half area of the specimen was unirradiated bymeans of a masking technique, and thus both irradiated andunirradiated regions were produced in the same specimen.
After the irradiation, measurements of AC-susceptibility ofthe specimen were performed in the temperature range fromroom temperature to ~550 K. The value of TC for the
specimen was derived from the temperature dependence of
the AC-susceptibility.
Although a large increase in TC with increasing the ion
fluence was observed for 1H, 4He, 12C, and 35Cl ion
irradiations, no change in TC was detected in the case of
200-MeV 197Au ion irradiation. This result suggests that thedominant energy transfer process for the increase in TC is
the elastic displacement. In Fig. 1, the values of ΔTC for all(b) Fe–Ni–Mn

200

1

H ( 1.0 MeV )He ( 1.5 MeV )C ( 5.0 MeV )35
Cl ( 12.0 MeV )

4

12

150
100
50
0
–4
10

–3

10

–2

10

–1

10

0

10

Energy deposited by elastic displacement, Φ × Sn ( keV/nm )3

Fig.1 Change in Curie temperature, ΔTC, plotted against
total energy deposited by elastic displacement, Φ×Sn,
for (a) Fe-Ni alloy, and (b) Fe-Ni-Mn alloy. Dottedlines are guides for the eye.

－ 172 －

JAEA-Review 2007-060

4-31 Effects of Multi-ion Beam Irradiation on
Microstructural Changes in Li2TiO3
D. Yamaki, N. Okubo, T. Aruga, T. Nakazawa, S.Jitsukawa
Division of Fuels and Materials Engineering, NSED, JAEA
Li2TiO3 is regarded as one of the most suitable candidates
for the solid tritium breeder material of D-T fusion reactors.
Simulation of the fusion reactor environment and hence thestudy of a synergistic effect of atomic displacement damage
in Li2TiO3 are presumed to be approached by asimultaneous irradiation with "triple" ion beams which
consist of O2+, He+ and H+ ion beams. In this study, theresults of the FT-IR photoacoustic spectroscopy (PAS) with
Li2TiO3 samples irradiated with the single ion beam, withthe triple ion beams simultaneously and with the triple ion
beams sequentially were analyzed for investigation of
microstructral changes.
The characteristics of the Li2TiO3 samples and theexperimental parameters used in this experiment were
described in ref1). The characteristic peaks in FT-IR PAS
spectra for non-irradiated Li2TiO3 sample were observed
around 680, 780, 880, 1090, 1430, 1480, 1570, 3150 and
3450-cm-1. In comparison to the reported spectra of TiO2
and Li2TiO3, 680- and 780-cm-1 peaks are identified from
Ti-O bond, 1570-, 3150- and 3450-cm-1 peaks are from theO-H bond in hydroxyls adsorbed on or near the surface, andothers are from C=O bond in Li2CO3 formed on or near thesurface by reaction with CO2 in the atmosphere1).
Among the observed peaks, irradiation effect is clearlyfound for 780-, 1090- and 3450-cm-1 peaks. In the previous
study, the radiation-dose dependence of the areas of thesepeaks indicates that TiO2, hydroxyl and Li2CO3 are formednear the surface by irradiation, and the amount of each was
found to be strongly affected by displacement per atom(dpa). Among them, the amount of the formed hydroxyl isaffected not only by dpa but also by the method of
irradiation, that is, the single, the simultaneous triple or thesequential triple irradiation. This may suggest that H+
implantation after irradiation degrades the generation ofhydroxyl (-OH) group near the surface by trappinghydrogen in the irradiation defects or radiolytic products2,3).
To verify the effect of H+ implantation on the generationof -OH group, the results of irradiation with O2+ ions (about
8 dpa) or He+ ions (about 1 dpa) with simultaneous, withsequential or without H+ implantation were compared.

The results so far are summarized in Table 1. The results
should be interpreted cautiously, since they are by no meanscomplete.
However, it likely supports the previous
suggestion that H+ implantation, especially in the sequential
irradiation, suppresses the –OH group generation near thesurface.
Under the fusion reactor operation, these microstructuralchanges may strongly affect the tritium release behavior
from Li2TiO3, durability of Li2TiO3, and compatibility of
Li2TiO3 with other components of the breeder blanket suchas structural materials. Further study of the irradiation
effects on these microstructural changes is needed toenhance the reliability of the related materials.
References
1)D.Yamaki et al, J.Nucl.Mater. 329-333 (2004)1279-1282.
2)D.Yamaki et al, JAEA-Review 2005-01 (2006) 212-214.
3)D.Yamaki et al, JAEA-Review 2006-042 (2007) 26.

Table 1. Summary of the effects of H+ implantation on the3450- cm-1 peak, which is due to the O-H bond. Notation as"A+B" means simultaneous irradiation of the beams A andB, and "A->B" means that irradiation with the beam B was
performed after closing of irradiation with the beam A.
Dpa
IrradiatedIons
Peak Area(arb. unit)
Dpa
IrradiatedIons
Peak Area(arb. unit)－ 173 －

≈8
O2+ + H+

O2+-> H+

571

362

He+

≈1
He+ + H+

He+-> H+

380

387

276

O2+
(not
measured)

JAEA-Review 2007-060

4-32 Structural Phase Transition of One-dimensional in Wireon Si Surface Studied by Reflection High-energy
Positron Diffraction
a)

a)

a)

M. Hashimoto , Y. Fukaya , A. Kawasuso and A. Ichimiya
a)

a,b)

b)

Advanced Science Research Center, JAEA, Faculty of Science, Japan Women’s University
1) were used as a parameter on the basis of the structure
model determined by SXRD3). The measured rocking curves
are in good agreement with the optimized curves at bothtemperatures4). The vertical distances of the In atoms were
determined to be d1 = 0.98±0.09 Å and d2 = 0.54±0.09 Å at
210 K, and d1 = 0.99±0.09 Å and d2 = 0.55±0.10 Å at 60 K4).
We found that the vertical positions of the In atoms do notchange during the phase transition.
Figure 2 displays the rocking curves measured for the
In/Si(111) surface at 53 K (8×2 phase) and at room
temperature (4×1 phase) at the [ 1 1 0 ] direction. The
rocking curves change with temperature. We calculated therocking curves at the [ 1 1 0 ] direction using the zigzag
chain structure determined by SXRD3). The measured
rocking curve at room temperature is in good agreementwith the curve obtained by calculation, as shown in Fig. 2.
On the other hand, the feature of the experimental results at
low temperature can not be reproduced by the calculation
using the zigzag chain structure and even using the trimer
structure5). We found that the rocking curve calculated using
the hexagon structure6), which was recently proposed by thetheoretical calculations, is in good agreement with theexperiment as shown in Fig. 2. In conclusion, themetal-insulator transition of the In/Si(111) surface at 130 K
occurs with the displacements of the In atoms from thezigzag chain to the hexagon structures.

Intensity (arb. units)

(444)

(333)

(222)

References
1) H.W. Yeom et al., Phys. Rev. Lett. 82, (1999) 4898.
2) A. Kawasuso et al., Rev. Sci. Instrum. 75, (2004) 4585.
3) O. Bunk et al., Phys. Rev. B 59, (1999) 12228.
4) M. Hashimoto et al., Surf. Sci. (2007), in press.
5) X. López-Lozano et al., Phys. Rev. B 73, (2006) 035430.
6) C. González et al., Phys. Rev. Lett. 96, (2006) 136101.
(111)

When one monolayer of In atoms is deposited on aSi(111)-7×7 surface, In/Si(111)-4×1 super-structure isformed (see Fig. 1). From various studies, this superstructure is considered to be a quasi-one-dimensional
metallic chain, which is composed of the upper and lower In
atoms having two different heights. The 4×1 structure istransformed into the 8×2 structure below 130 K,
accompanying the metal-insulator transition1). Thistransition is considered to be a Peierls transition with theformation of charge-density wave from angle-resolved
photoelectron spectroscopy1). However, the mechanism of
the phase transition between the 4×1 and 8×2 structures is
not fully clarified because the atomic configuration of the
8×2 phase is still unknown. In this study, on the basis of therocking curve analyses using reflection high-energy positron
diffraction (RHEPD), we will report on the atomic
displacement of the quasi-one-dimensional metallic chainsdue to the phase transition.
The RHEPD experiments were carried out in a UHVchamber equipped with a 22Na positron source and electro
magnetic lenses2). The positron energy was set at 10 keV.
Two azimuthal angles were chosen to measure the rocking
curves; (1) 7.5°-off oriented from the [ 11 2 ] direction(one-beam condition) and (2) the [ 1 1 0 ] direction (chainparallel). The rocking curves were obtained by rotating thesample from 0.3° to 6.0° with an interval of 0.1°.
We measured the rocking curves at 210 K (4×1 phase)and 60 K (8×2 phase) under the one-beam condition, where
the curve mainly depends on the vertical position of thesurface atoms. The profiles of the rocking curves do notchange with temperature (60 K and 210 K). To determine
the vertical positions of the In atoms, we calculated thecurves based on the dynamical diffraction theory. Two
different vertical positions of the In atoms (d1 and d2 in Fig.

: exp
: cal

53 K

RT
0

Fig. 1. Top and side views for In/Si(111)-4×1 surface. The
large black circles represent the topmost In atoms. Gray
and white circles indicate the Si atoms in the first and the
deeper layers, respectively.

1
2
3
4
5
Glancing angle (deg)6

Fig. 2. RHEPD rocking curves for the In/Si(111) surface atthe [ 1 1 0 ] direction at 53 K and RT. The circles and thesolid lines show the measured and calculated curves,
respectively.

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JAEA-Review 2007-060

4-33 Reflection High-energy Positron Diffraction Study on
Surface Structures and Dynamics
a)

a)

a)

Y. Fukaya , M. Hashimoto , A. Kawasuso and A. Ichimiya
a)

a,b)

b)

Advanced Science Research Center, JAEA, Faculty of Science, Japan Women’s University(b) TC = 123 K: exp: cal (hex): cal (tri)

: exp
: cal

Intensity (arb. units)

(444)

(333)

60 K

(222)

Specular intensity (arb. units)

(a)

(111)

The surface atoms reconstruct to reduce the surface
energy and hence the super-structures, which are different
from the bulk, are formed on the surface. To investigate thesurface structure and properties in detail, thesurface-sensitive tool is needed. Thus, we tried to apply
positron diffraction to the surface study1). The positrons are
the antimatter of electrons and have a positive charge. Whenthe positrons are incident on the surface at grazing angle, thetotal reflection takes place due to the presence of positive
barriers of crystals2). The diffracted positrons under the totalreflection condition are very sensitive to the topmost surface.
We studied the surface structure and the dynamics ofsuper-structures fabricated on the crystal surface, by using
the reflection high-energy positron diffraction (RHEPD).
The experiments were carried out in an ultra-high vacuum
chamber equipped with a 22Na positron source andelectromagnetic lenses3). The intensity of the diffraction
patterns were enhanced using a micro-channel plate with aphosphor plane and recorded by a CCD camera. The
accelerating voltage of positron beam was set at 10 kV. To
measure the rocking curve, the glancing angle was changed
from 0.5˚ to 6˚ by rotating the sample.
By depositing one monolayer of In atoms on the Si(111)
surface at 673 K, one-dimensional structure of 4×1-In is(1/3 1/3)

Total reflection

0

1

2

3

4

5

6

50

Glancing angle (deg)

(c)

100

150

200

250

Temperature (K)(8/21 11/21)(13/21 10/21)

1/7 Laue zone

(20/21 17/21)

Fig.1 (a) RHEPD rocking curve for the Si(111)-8×2-In
surface, (b) Temperature dependences of the totalreflection intensities for the Si(111)-√3×√3-Ag surface,and (c) RHEPD pattern for the Si(111)-√21×√21-Ag
surface.

formed. The 4×1 phase is transformed into 8×2 phase below
130 K. The phase transition is considered as Peierls
transition. However, the phase transition is still in debate
because the surface structure of the 8×2 phase is unknown.
The circles in Fig. 1(a) shows the rocking curves measured
from the 8×2 phase at the [ 1 1 0 ] direction. From theanalyses based on the dynamical diffraction theory, we
found that the 8×2 structure consists of hexagons, nottrimers. This result supports the recent theoretical
calculations. We also confirmed that the 4×1 structure
corresponds to the zigzag chain model. Consequently, the
8×2-4×1 phase transition is accompanied by the large
displacements of the In atoms.
When one monolayer of Ag atoms is deposited on theSi(111) surface at 773 K, the super-structure of √3×√3-Ag isformed. The phase transition from one √3×√3 to another√3×√3 phase takes place at 123 K. Although the √3×√3-Ag
surface has been studied by various techniques, the phasetransition remains unresolved. Figure 1(b) shows thetemperature dependences of the total reflection intensities.
We observed that at below 123 K, the (1/3 1/3) spot
intensity drastically increases with decreasing temperature.
By the intensity analyses, we found that the intensity change
can be completely explained by considering theorder-disorder phase transition4).
By depositing small amounts of the Ag atoms on the√3×√3-Ag surface at 110 K, the super-structure of√21×√21-Ag phase is formed accompanied by drastic
increase of the surface conductivity. Although several
structure models were proposed by many researchers, there
is no consensus. From the results of the rocking curve
analyses, the five different structures were selected for a
possible structure from candidates for the models. Finally,
from the line profile of the 1/7th Laue zone (see Fig. 1(c)),
we found that the additional Ag atoms are situated on thelarge Ag triangle of the substrate with triangular shape at thecorner of the unit cell5).
References
1) A. Kawasuso and S. Okada, Phys. Rev. Lett. 81 (1998)
2695.
2) A. Ichimiya, Solid State Phenom. 28&29 (1992) 143.
3) A. Kawasuso et al., Rev. Sci. Instrum. 75 (2004) 4585.
4) Y. Fukaya, A. Kawasuso, and A. Ichimiya, Phys. Rev.
B 75 (2007) 115424.
5) Y. Fukaya, A. Kawasuso, and A. Ichimiya, Surf. Sci.
600 (2006) 3141.

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JAEA-Review 2007-060

4-34 Characterization of Ion Beam-induced Buried Oxide
Layer Using a Slow Positron Beam
M. Maekawa and A. Kawasuso

Advanced Science Research Center, JAEA
1.20
S parameter

R. T.
o
600 C
800oC
1000oC
SiC

(a)

1.15
1.10

(b)

R. T.
o
600 C
o
800 C
o
1000 C

1.05
1.00
0

5
10
15
20
25
Positron Incident Energy [keV]

30
0

5
10
15
20
25
Positron Incident Energy [keV]30

Fig.1. S parameters for the bulk SiC andoxygen-implanted SiC of (a) as-implanted state and (b)after annealing at 1400 °C. S parameters are normalized
to these for bulk SiC.
1.6
1.4
Ratio to SiC

For the high-power silicon carbide (SiC) devices,
SiC-On-Insulator (SiC-OI) structure is suitable. Ion
implantation is one of the methods to make the SiC-OI
structure1). However, the properties of radiation defects havenot been fully clarified. We attempted to investigate thedefects in the SiC-OI structure using the positronannihilation spectroscopy which is suitable to detectvacancy-type defects.
Samples were formed by the oxygen implantation to
the n-type 4H-SiC substrate with the energy of 200 keV todose of 1x1018 cm-2. High temperature implantation was
carried out for avoiding the amorphization. After
implantation, samples were annealed in argon ambient tat
1400 °C. The Doppler-broadening of annihilation quanta
was measured as a function of incident positron energy (E).
The obtained Doppler broadening spectra werecharacterized by S-parameters which are enhanced by the
positron trapping at the vacancy defects.
Figure 1(a) shows S parameters of as-implantation
sample of various implantation temperatures. The mean
implantation depth of E = 4~8 keV corresponds to theoxygen implanted region. After implantation, S paremter
increases in the whole energy range. This indicates thatvacancy defects are formed by ion implantation. A
remarkable increase of S paramter in the top SiC layer(E=1~3keV) is observed. This indicates that larger vacancy
clusters are created in this region. The well-defined SiO2
layer is not necessarily formed because S parameters of theoxygen implanted region (E=7keV:S=1.05) is apparently
lower than those of SiO2 bulk value (S = 1.15) 2). This is
attributed to the existence of competitive trapping centers,such as vacancy defects which give relatively low S
parameters 3). Even if the implantation temperature
increased, the clear SiO2 layer was not appeared. In the
top-SiC layer (E=1~3 keV), a remarkable increase of S
parameter is observed. S parameter increases withimplantation temperature. This indicates that larger vacancy
clusters are easily created at higher temperature.
Figure 1(b) shows the S parameters obtained after
annealing at 1400 °C. S parameters at E > 10 keV decreases
to the bulk value(S=1) suggesting the recovery of defects.
At the region of E = 5~10 keV, a shoulder appears. To
determine the electron momentum distribution more indetail,coincidence
Doppler-broadening(CDB)
measurement was performed. Ratio curve of E=7 keV to the
SiC bulk obtained from the specimen implanted at 800 °C
are shown in Fig.2. The obtained ratio curve resembles theannihilation at the interface layer of the SiO2/SiC interface

Ion implantation region
SiO2/SiC interface

1.2
1.0
0.8
0
5
10
15
20
-3
Electron Momentum [x10 m0c]

Fig.2. Ratio curve of E=7keV to the bulk SiC obtained
from the specimen implanted at 800°C after annealing at
1400 °C.
produced by conventional oxidation as shown on solid line
in Fig.2 2). That is, the oxygen implanted layer contains
vacancy defects with oxygen dangling bonds. In the top-SiC
layer, S parameters are still high even if the thermal
annealing was performed. This indicates that microvoids
were formed.
In summary, defects in SiC-OI structure formed byoxygen implantation were probed by positron annihilation
spectroscopy. The defective SiO2 layer seems to be formedin the oxygen-implanted region. Radiation defects are
hardly removed even if higher implantation temperatures
were applied. In the top-SiC layer, larger vacancy clusters
are created. From this study, it is suggested that moreadvanced techniques should be developed in order to obtaina defect-free SiC-OI structure by ion implantation method.
References
1) N. P. Barradas, C. Jeynes and S. M. Jackson, Nucl.
Instrum. Meth. B136-138, 1168 (1998).
2) M. Maekawa, A. Kawasuso, M. Yoshikawa, A. Miyashita,
R. Suzuki and T. Ohdaira, Phys. Rev. B73, 014111 (2006)3)M. Maekawa, A. Kawasuso, M. Yoshikawa, A.
Miyashita, R. Suzuki and T. Ohdaira, Physica B:
Condensed Matter, 376-377, 354-357 (2006).

－ 176 －

JAEA-Review 2007-060

4-35 Development of 2-Dimentional Nuclear Reaction
Micro-analysis Technique of Boron-doped Materials
a)

)

c)

c)

H. Shibata , Y. Kohno ｂ , T. Satoh , M. Oikawa , J. Hagaa)c)

and T. Sakaid)b)

Graduate School of Engineering, Kyoto University, Department of Materials Science andc)Engineering, Muroran Institute of Technology, Department of Advanced Radiationd)Technology, TARRI, JAEA, Policy Planning and Administration, JAEA

The microanalysis of trace amount of boron has been carried out using 1 µm proton microbeam from 3MV single ended
electrostatic accelerator of TIARA facility. Steel specimens containing 20-100 ppm boron have been bombarded by 1.7 MeV
proton beam for gamma ray detection and 1.32MeV H2+ beam for alpha particles. In 2006 the maps of boron distribution
have been measured by detecting 3.7 MeV alpha particles from the 11B (p, α) 8Be nuclear reaction mainly. As a result of
imaging, segregation of several microns sized boron precipitates, which has been already observed by detecting gamma ray,
could be clearly seen in this method.
鉄鋼材料に微量のホウ素を添加することにより強度特性を良くすることは経験的に知られているが、鉄鋼中でのホウ素の振舞いについては殆ど解明されていな
い。これは鉄鋼中に限らず、ホウ素の局所的かつ定量的な元素分析が、SIMS、EDXA、EELS などの分析方法を用いても、難しいことによる。
ホウ素の局所的（三次元的）な定量元素分析ができるようになれば、ホウ素添加鉄鋼材料の強度特性とホウ素の分布の関係を明らかにすることができ、ホウ素分布を最適化するような熱処理法等の開発を可能にする。これは、ホウ素の効率的な処理によって、クロム、
モリブデンなどの鋼中合金元素を必要とすることなく所要強度の実現を可能にするものであり、生産コストの低減化、省資源化、そして環境に優しいリサイクル
マテリアルを可能とする。
材料中に含まれる微量のホウ素の分布を空間的、定量的に精度良く調べるために、陽子マイクロビームとホウ素との核反応を利用した分析法を採用し、新たな分析手法の確立を目指すのが本研究テーマの目的である。
2006 年度は TIARA の大気マイクロ PIXE のポートを用いて、陽子とホウ素の核反応で放出されるα粒子の二次元分布測定を試みたので報告する。
ホウ素の定量的な分布を求めるために、2004 年度より
10
B(p,α'γ)7Be の核反応によって放出されるγ線を、半導体検出器を用いて測定を行ってきた。さらに 2005 年
度には新たに製作したアニューラ型半導体検出器（Raytech 社製）を用いたα線検出を試みた。図 1 に測定の概念図を示す。検出器にはビーム貫通穴が空いており、真空チャンバー内（約 1x10-3 Pa）に置かれている。試料はγ線検出の場合と同じチャンバーのサンプ
ルホルダー窓に取り付けられていて、γ線とは反対のビームが照射される側で計測する。11B (p,α) 8Be の核反応で放出される 3.7 MeV のα粒子を測定することでγ線と同じようにホウ素の分布を測定できる。この核反応は約 800 keV にピークを持つ半値幅約 400 keV の幅広い共鳴反応である。そのため、用いたビームは 1.6
MeV の水素分子ビームで、固体内に進入した直後には0.8 MeV のエネルギーを持つ 2 個の陽子になることを利用した。Raytech 社製の検出器が不調であったので、2006 年度は Canberra 社製のアニューラ型半導体検出器（ANFD 300-20-300RM）を用い、二次元検出に成功した。
試料として34 ppmのホウ素を含んだ鉄の板（10x10x1mm）を用いた。ホウ素を含む試料はその量とその他の含有物によっていくつかの種類に分けられるが、今回準備された試料では、Bの他、C, Si, Mn, P, S, N, Cr, Vを含む。2005年度までのγ線検出の実験で、鉄鋼中にあるホウ素は直径10ミクロン位の粒状になって分布しているのが観察されている。
2006年度では11B (p,α) 8Beの核反応によって放出されるα粒子ついて測定し、図２のようにγ線と同様な分布を得ることができた。この試料には添加物として微量のクロムやバナジウムが添加してあり、これらの添加物がホウ素の凝集に関係していることが考えられる。
また鉄鋼中にあるホウ素は粒界に凝集しているといわれており、一様に分布するホウ素よりはるかに密度が高いと思われるので 20 ppmでもγ線測定が可能だと考えられる。残念ながらこの測定では鉄の粒界の状況がわかからないので、ホウ素が鉄鋼中にどのように分布しているかはわからない。また定量性についても、
まだγ線やα粒子の収量に対する較正がなされていないのでこれからの課題であるが、BN試料の収量と比較することで定量性を出すことを考えている。

αMicrobeam
50μm

Fig.1. Schematic view of experimental setup for α-particle
measurements.

200μm

50μm

Fig.2. A typical α -particle image of 34 ppm boron
contained in a steel specimen bombarded by 1.32 MeV
molecular hydrogen microbeam.

－ 177 －

JAEA-Review 2007-060

4-36 Three-dimensional Measurement of Density in Minute
Biological Samples by STIM
T. Satoh, M. Oikawa, J. Haga, T. Kamiya and K. Arakawa
Department of Advanced Radiation Technology, TARRI, JAEA
When samples which have thickness variation andinternal constitution are analyzed with an in-air
micro-PIXE system1), X-ray yields have to be correctedusing X-ray production cross sections and linear
attenuation coefficients. For that purpose in the case of
biological samples, it is necessary to measure thethree-dimensional distribution of carbon, hydrogen, andoxygen, which are the matrix of cells. Because it isdifficult to measure them with spatial resolution of a few
microns by micro-PIXE analysis by itself, we used
Scanning Transmission Ion Microscopy (STIM)2), which
can measure it easily using a particle detector located justbehind the sample in the atmosphere.
In our previous study3), the elemental map by
micro-PIXE for a spherical sample could be corrected by
STIM under the assumption the ratio of major elements inthe sample was constant. Thus X-ray yields fromsymmetric and uniform samples can be fully corrected by
STIM only. But if there are projection maps by STIM in
all directions, the tomograms can be acquired in the same
way as CT scan. This method is called STIM-CT4).
We attempted in-air STIM-CT of plant cells to get
three-dimensional shape, and the good tomogram of thesample was acquired in 20055). In 2006, we could get
the tomogram of an insect’s head. Since it has generally
hollow shape, it is necessary to measure the internal
structure using STIM-CT.
In this series of study, the 3MV single-ended
accelerator and the micro-PIXE system at the TIARA
were used. The 3 MeV proton microbeams were
scanned over a target. The diameter of the microbeam
was about 1 μm. Polycarbonate foil 5 μm thick was used
as a beam extraction window. A target was glued on theneedle just behind the extraction window, and was rotatedby 180° at intervals of 15°. A surface barrier detector
was placed behind the target.
Figure 1 is a photograph of the test sample. It was ahead of a tiny insect. Figure 2 shows the projected
image of the sample and Figure 3 is the tomogram
reconstructed using the back projection method with theShepp&Logan filter. Using all tomograms such as Fig. 3,
three-dimensional reconstruction of the sample could be
realized as in Fig. 4.

500μm

Fig 1.

Optical microscope image of an insect’s head,
which glued on a metal needle.

A

Fig 3. Tomogram atline A in Fig. 2.

Fig 2.

Projected image ofthe insect’s headobtained using STIM.

Fig 4.

Three-dimensional image of an insect’s head.
This image was reconstructed from tomograms
such as Fig. 3.

References
1) T. Sakai et al., Int. J. PIXE Vol. 10 Nos. 3 & 4 (2000) 91.
2) J. C. Overley et al., Nucl. Instr. Meth. B 30 (1988) 337.
3) T. Satoh et al., Nucl. Instr. Meth. B 249 (2006) 234.
4) C. Michelet et al., Nucl. Instr. Meth. B 150 (1999) 173.
5) T. Satoh et al., JAERI-Review 2006-042 (2007) 167.

－ 178 －

JAEA-Review 2007-060

4-37 In-air Micro-PIXE Analysis of Asbestos in Asbestos
Exposed Lung
a)

a)

a)

a)

b)

b)

Y. Shimizu , K. Dobashi , T. Kusakabe , T. Nagamine , M. Oikawa , T. Satoh ,
b)
b)
b)
b)
b)
a)
J. Haga , T. Ookubo , Y. Ishii , T. Kamiya , K. Arakawa and M. Moria)

The 21st Century Program, Graduate School of Medicine, Gunma Universityb)
Department of Advanced Radiation Technology, TARRI, JAEA

Asbestos were causative agents of pulmonary fibrosis and cancer. To identify inhaled asbestos in lung, lung tissues fromasbestos exposed patients were analysed by in-air micro-PIXE (Particle Induced X-ray Emission). The localization ofasbestos body composed by silica, iron, and magnesium were identified in the lung, and other metals of titanium andaluminium were also observed. In-air micro-PIXE was considered as useful to identify asbestos in lung tissue.
であった。この成分の違いが、アスベスト患者の癌発
アスベストとは、天然の鉱物繊維で長さは約8 μm,症率の高さに関与するか今後の検討課題である。
幅約0.1 μm、断熱性、耐火性、防音性、耐腐食性に優Area size
れており、建築用製材として多く用いられてきた。ク
Normal lung
910μmx910μm
リソタイル（白石綿）、クロシドライト（青石綿）、Si
Mg
Fe
アモサイト（茶石綿）などがある。アスベスト吸入は肺に炎症を惹起し、肺線維症や肺癌発症と関係があるといわれている。このアスベストの肺内における局在と ア ス ベ ス ト 組 成 を 大 気 中 マ イ ク ロ PIXE （ Particle
Induced X-ray Emission）分析を用いて解析することを試みた。
Asbesto lung
対象患者：Asbetos group: Asbestos吸入歴があり、肺癌を合併した患者肺の癌以外の部分とControl group:
Asbestos吸入歴がない肺癌を合併した患者肺の癌以外の部分の肺組織の凍結切片を作成し、それを表面に
PIXE用の高分子フィルムを張ったスライドグラス上に載せて乾燥させた。肺組織を含むフィルム膜とともにArea size 57μmx57μm Normal lung
肺切片を切り出しサンプルフォルダに固定し、3 MeV
Mg
Fe
Siのプロトンビームを照射して、大気中マイクロPIXE分
1)
析を行った。
結果：Si, Mg, Feおよびそれらが混ざったアスベストを検出できた。得られたマイクロPIXE画像をFig. 1に示す。正常肺では組織中少量のSiを測定できたが、Mg
や、Feはほとんど検出されなかった。一方、アスベス
Asbesto lungト肺組織中からは、無数のSiが検出されると同時に、その部位にMgやFeも一緒に検出され、無数のアスベス
トが肺に沈着している様子が明らかとなった。さらに、
今回検出されたアスベストは、Chrysotile （白石綿,
Mg3Si2O5(OH)4:わずかに鉄を含む）もしくはAmosite（ 茶 石 綿 , (Mg, Fe)7Si8O22(OH)2 ） が 考 え ら れ 、Crocidolite（青石綿, Na2(Fe2+3Fe3+2)Si8O22(OH)2）では無Fig. 1. Micro-PIXE images of elemental distributions
かった。また、アスベスト小体は組織間隙に刺さったof Mg, Si and Fe in normal lungs and asbestos lungs.
ようになっている様子が2次元的に観察できた。以上
Referencesのように、大気マイクロPIXEによる観察で、アスベス
1) T. Kusakabe, K. Nakajima, K. Suzuki , K. Nakazato, H.
トの種類や、組織内での存在部位が、明らかになった。
Takada, T. Satoh, M. Oikawa, K. Kobayashi, H.
【考察】アスベスト暴露歴のない肺では、わずかなSi
Koyama, K. Arakawa, T. Nagamine, The changes of
しか見られないが、アスベスト肺では、Siが、密度濃
heavy metal and metallothionein distribution in testis
く、広範囲に一様に分布している像が見られ、明らか
induced by cadmium exposure. Biometals, 2007 Aprに多量のSiを吸入していることがわかる。さらに、ア19; [Epub ahead of print].
スベスト暴露歴のない肺のSiは、その部位にほとんど金属を含まないが、アスベスト肺のSiの部位には、Mgなどの金属が同時に存在しており、その違いは明らか－ 179 －

JAEA-Review 2007-060

4-38 The Present Situation and Problems of the Analysis of
Boron Micro-distribution in Tumor Cells Using
Micro-PIXE and PIGE
a)

a)

a)

a)

a)

K. Endo , Y. Shibata , T. Yamamoto , K. Nakai , A. Matsumura ,
b)
b)
b)
b)
c)
T. Sato , M. Oikawa , K. Arakawa , T. Kamiya and K. Ishiia)

Department of Neurosurgery, Institute of Clinical Medicine, University of Tsukubab)Department of Advanced Radiation Technology, TARRI, JAEAc)
School of Engineering, Tohoku University

We have applied micro particle induced X-ray emission (micro-PIXE) to determine inter- and intracellular distribution ofboron (10B). Because the energy of micro-PIXE from 10B is too low, we employed a method to detect gamma-ray produced
from the nuclear reaction of 10B(p,αγ) 7Be, namely particle induced gamma-ray emission (PIGE). We showed the results ofinter and intracellular distribution of boron elements in tumor tissue using micro-PIGE. However, we analyzed manybackground too and still can not detect the true boron elements. So further investigation is necessary to obtain higher spatial
resolution and the optimization of the measurement time or the improvement of the sampling methods should be investigated.
In future, this method will be applied to analyze the intracellular micro-distribution of the capture element and developmentof new drugs for NCT.
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悪性脳腫瘍に対する放射線治療法の一つとして硼素
中性子捕捉療法(BNCT)の臨床研究が進められているが、その効果は硼素元素の細胞内分布状態に大きく影響を受けると考えられている。これまでにも硼素元素の腫瘍内での分布やその動態の研究が報告されてきたが、画像的に明らかにしたものはなかった1,2)。
本研究の目的は腫瘍細胞内での硼素元素の分布状態を測定・画像化することである。そのためTIARAのSingle-ended acceleratorを用い、特にγ線の測定によるparticle induced γ-ray emission (PIGE)法を用いることでまず硼素10(10B)の画像化に成功した。今回はその後の現状と課題について報告する。
はじめにIn vivo実験として脳腫瘍にBSHが集積していることを確認、細胞レベルでの分布状態を明らかにするために、まずラット脳に９L腫瘍細胞を移植しこれを２週間生育した。２週間後にBSHを静脈投与し、その数時間後にこれを安楽死させ脳腫瘍及び正常脳組織を採取した。これを厚さ20μｍに切載しマイラー膜上に固定。正常脳、脳腫瘍組織・細胞における硼素元素の分布状態を比較した。
図1左は正常脳組織の厚さ20μｍ切片をマイラー膜上に固定し、燐(P)や硫黄(S)の分布を指標に測定画像化したもの、また右は硼素元素(10B)チャンネルにおける測定分布図である。しかし硼素元素は測定スペクト
ル上ピークとして認められず周辺バックグランドと同等レベルであり、これらのドットはほとんどがバック
グランドと考えられた。また図2左は脳腫瘍組織の厚さ20μｍ切片を同様にPやSの分布を基に画像化したもの、また右は硼素元素分布図である。脳腫瘍組織では測定
スペクトル上硼素元素チャンネルにおいてピークを形成し、脳腫瘍組織からは硼素元素が測定された。これは脳腫瘍組織にはBSHが集積していることを示している。
しかしながら本来の目的である細胞レベルでの硼素
元素分布の明確な画像化は困難であった。それは脳腫瘍を採取する際にある程度の組織破壊を伴っている可能性があること、また摘出した脳腫瘍を急速凍結する
際に組織内での凍結速度にギャップが生じることが予

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Fig.2 Distribution of tumor cells(P) and 10B
想され、これに伴う細胞内・細胞間での元素の移動の可能性が考えられること、さらにこれを10～20μｍの厚さに薄切するのは困難であり、その際に腫瘍組織・細胞の破壊を伴っている可能性が考えられる、などのためである。そのため図1，2とも細胞分布は不明瞭な形態を呈しており、固定過程で生じたと思われる亀裂らしい跡も認められている。当然細胞内容の移動、偏移も生じているものと想像され、図2の如く硼素元素は測定されたものの、バックグランドの問題とともに細胞レベルでの分布状態は不明瞭な結果であった。
これらの問題点を改善するために、ある程度の大きさ、体積のある試料の急速凍結方法、また組織・細胞破壊をできるだけ伴わない薄切方法及びその固定方法などの新たな開発・検討が今後必要と考えている。
References
1) Coderre JA, et al., Radiat Res 149 (1998) 163-170.
2) Wegden M, et al., Nucl Instr and Meth in Phys Res B
219-220 (2004) 67-71.

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JAEA-Review 2007-060

4-39 Standard Reference Material for Determination of Trace
Elements in Biological Materials by Micro Beam PIXE
a)

a)

b)

c)

c)

Y. Iwata , T. Konno , K. Ishii , M. Fukuda , T. Kamiya , T. Satohc)and M. Oikawac)a)Department of Chemistry, Faculty of Education and Human Studies, Akita University,
Department of Quantum Science and Engineering, Graduate School of Engineering,c)
Tohoku University, Department of Advanced Radiation Technology, TARRI, JAEAb)

Standard Reference Material (SRM) is indispensable to the calibration of apparatus and the evaluation of the accuracy
and precision of analytical technique. Previous work, we showed utilities of several macro porous anion and cationexchange resins for micro PIXE analysis. In this work, we made SRM containing the known amount of Ca2+ and trace
amount of essential elements for living matter, such as Fe3+, Ni2+ and Zn2+ in cation-exchange resin. Macro porous anionexchange resin, Macro-Prep 25S (BioRad) was suspended in 0.01 M HNO3 and added the known amount of standard
solutions. The concentration of trace elements in the resin was 20-60 ppmv. Individual particle of the resin was subjected
to 3 MeV proton bombardments by micro beam system of TIARA. It was found the macro porous nature of the resin (poresize; 72.5nm) allows cation to access the exchange sites located throughout the matrix. This SRM is similar to biologicalcell because it is spherical in shape and its matrix elements are carbon, oxygen and hydrogen. This SRM made of macroporous resin has a possibility for use as SRM for determination of trace elements in biological samples by micro beam PIXE.
PIXE分析を含め、ほとんどの機器分析において、装置の校正や分析結果の相互比較のために標準物質(SRM)は、不可欠である。 これまで、粒径が25から
100 μmで球状の陽イオン交換樹脂に、微量元素を付着させたSRMを作成し、TIARAマイクロPIXEシステムで、生体試料分析に対する有効性を報告してきた。この検討では、TIARAにおける Cu、Zn等の生体必須元素の画像化の下限値（5 ppm程度）を求めた1)。また粒径25ミ
クロンの多孔質の構造を持つマクロポーラス型陽イオ
ンおよび陰イオン交換樹脂に、微量の金属陽イオンを球体全体に均一に付着させた粒子状試料の作成に成功
し、分析感度、分解能、照射安定性において優れたSRMになりえることを示した2）。
本研究では、生体中の微量元素として、Fe、Ni、Cu
を選び、これらを同時にマクロポーラス型陽イオン交
換樹脂に添加した。元素添加量と特性X線強度について検討し、生体中の微量元素分析用標準物質としての有用性を報告する。
実験 樹脂への金属イオンの吸着 純水中で懸濁させたマクロポーラス型陽イオン交換樹脂Macro Prep
25S（スルホン基型 粒径25 μm、BIORAD）を、メスピペットで吸い上げ、樹脂の体積を測定した。樹脂を含む懸濁液に、Ca2+ 、Fe3+ 、Ni2+ およびCu2+ を含む標準溶液を加え、振とうした。樹脂体積あたりの含有量は、
Ca2+ は400 ppmvの一定量とし、Fe3+ 、Ni2+ およびCu2+ は、
0、20、40、および60 ppmvとした。
マイクロPIXE分析 ターゲットホルダー上に、樹脂の懸濁液を付着させ、こよりで水分を吸い取った。顕微
鏡下で、樹脂が重なり合わないように、樹脂をばらまいた。マイクロPIXEシステムにより3MeV pビームをサブミクロンに絞った。スキャンエリアを30 x 30 μmとし、大気中200-300 nCの照射を行った。
結果と考察 標準物質の調製 一定体積の樹脂と目的元素の標準溶液を混合するだけで、簡便に調製することができた。Fe3+ イオンの加水分解を防ぐために
0.1M硝酸酸性下で振とうした。この陽イオン交換樹脂の吸着反応は、分配現象としてよく研究されており、大部分の+2、+3の陽イオンに適用が可能である。
標準物質のマイクロPIXE像 一粒のマクロポーラス型
イオン交換樹脂について、添加した微量元素（Ca, Fe,
Ni, Cu）ならびにイオン交換基に含まれるSの画像化に成功した。SとCaの分布は、樹脂が球体とした場合とよく一致しており、樹脂内にイオン交換基が均一に分布し、その交換基と金属イオンが反応することが確かめられた。生体中で微量であるFe, NiおよびCuにつ
いては、その添加量を20から60 ppmvと変化させたが、いずれの場合も樹脂内の元素分布を画像化できた。
微量元素の定量感度 標準物質の使用目的で最重要課
題は、機器の校正、すなわち分析感度の定量化である。
樹脂に一定量添加したCaからの特性X強度に対するFe,
Ni, Cuの強度をプロットした(Fig１)。Fe, Ni, Cuの添加濃度に対して原点を通る直線となり、定量性も優れていることが確かめられた。以上の検討から、生体試料の画像化の精緻化における微量元素分布の定量化への有効であることが確かめられた。
○：Fe
◇：Ni
□：Cu

Fig.1 Relationship of Concentration Trace Elements andRelative X-ray Intensity of based on Ca Kα
References
1) Y. Iwata et al., TIARA annual report 2004 (2005) 320.
2) Y. Iwata et al., JAEA Review 2006-042 (2007) 171.

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JAEA-Review 2007-060

4-40 Measurement of BrdU in Mouse Brain by
In-air Micro PIXE Analysis
a)

a)

b)

b)

b)

b)

E. Sakurai , K. Yanai ,K. Ishii , R.Oyama , M. Sakamaki , H.Hiromichi ,
b)
c)
c)
c)
c)
c)
S.Matsuyama ,T. Kamiya , T. Satoh , J. Haga , M. Oikawa and K. Arakawa
a)Department of Pharmacology, Tohoku University School of Medicine,
Department of Quantum Science and Energy Engineering, Tohoku University,c)
Department of Advanced Radiation Technology, TARRI, JAEAb)

1. Introduction
There are many reports that trace elements might berelated to cerebral nerve diseases, such as Alzheimer’s
disease1). To examine changes of spatial distributions oftrace metal elements in cells, organs or tissues using various
kinds of disease model, it is useful to establish a newpharmaco-therapeutics.
In this study, we developed a method to analyze elements
in brain slices using histamine receptor gene knockout miceon the basis of Micro-PIXE analysis.

related to the cognition. BrdU labeling hippocampal
neurogeneses were observed in the brain slices of H1KO
and their wild type mice by the use of micro-PIXE analysis.
Figures 1 and 2 show the beam irradiation image of a brainslice and the distribution image of bromine in the region of
100 × 100μm 2 in the brain slice of Fig 1.

４

2. Experimental method
1) Target preparation of brain samples for PIXE analysis
We examined 4 target preparations: ① brains were
removed and stored at –80 ℃, ② brains were removed
and immediately quick-frozen in 2-methylbutane cooledin liquid nitrogen, ③ brains were removed and treatedwith sucrose solution and stored at –80 ℃, ④ brains were
removed and immediately quick-frozen in dry ice to–40 ℃.
The target preparation of ④ was most suitable for thisstudy. Trace metal elements were difficultly detected in
the frozen conditions of ① and ③. In the condition of ②,
the brains were delicate and it was difficult to make theirslices.
2) Histamine receptor gene knock out mice and theirneurogeneses
Histamine H1 receptor gene knock out mice (H1-KO)
and their wild type mice were bred in our laboratory.
5-bromo-2’-deoxyuridine (BrdU) of 75 mg/kg were
injected into mice 4 times at 2-hour intervals. Each brain
was cryosectioned sagittally at 16μm thickness. The brainslices were mounted on polycarbonate films, which were
processed with 5N sulfuric acid. The brain slices were
examined by the micro-PIXE analysis with 3 MeV-proton
micro-beams of beam currents of ~ 120 pA.
3. Results and discussion
H1 receptor antagonists are widely used to such as a
medicine for a cold or to relieve itching. However it is wellknown that sedative antihistamines induce cognitive
decline in human through blockage of H1 receptor. H1KO
mice showed impaired leaning and memory than their wild
type (C57BL/6) mice. It was recently reported thatnewborn cells within 24 hours in the hippocampus are

２

３

Fig. 1 Beam irradiation image Fig. 2 Image of bromineof brain slice of wild type mouse.
(100 × 100μm 2)

pg/μm20.00030.000250.00020.000150.00010.00005
0

Wild

H1-KO

Fig. 3 Amount of bromine in 1μm 2 of brain slices
The amounts of bromine in the slices of wild type mice andH1KO mice are shown respectively in Fig. 3.
The amount of Bromine in the case of H1KO mice is small
compared with that of wild type mice. This result is accord
with the results of other physiological studies using H1-KO
and their wild type mice2).
Here, we presented the difference of accumulation of BrdU
in the brain of H1-knock out mouse from that of its wild
type mouse by the use of micro-PIXE which can be used toclarify the roles of trace elements in psychotic diseases suchas depression, schizophrenia and Alzheimer’s disease.
4. References
1) Okamura N et al. Br. J. Pharmacol., 129, 2000.
2) Dai H et al. Neurosci. Res., 57, 2007.

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JAEA-Review 2007-060

4-41 Monte-Carlo Particle Trajectory Simulation Studyon Classification of Structure of 3-MeV C3 Cluster Ion
a)

a)

a)

b)

M. Adachi , Y. Saitoh , A. Chiba , K. Narumi , K. Yamadaa)a)and T. Kanekoc)b)Department of Advanced Radiation Technology, TARRI, JAEA, Advanced Researchc)Center, JAEA, Department of Applied Physics, Okayama University of Science.

We have studied interaction of swift cluster ion beamwith matter. The interaction is well described by the nuclear
collision of projectiles and target atoms with the many bodyeffect, as far as the projectile speed is lower than the Bohr
speed vB ≅ 2.19×106 m/s. When the speed exceeds vB, theinteraction of the swift cluster ion is caused mainly by theelectronic collision, and the interaction mechanism has not
yet been revealed. The interaction caused through theelectronic collision involving a many body effect ofprojectile itself suggests us necessity for revealing therelation between a projectile charge state and time intervalof irradiation between each constituent ion or a cluster
spatial structure. We have therefore developed ameasurement system1), which realizes simultaneous
observation of charge states and a planar pattern of cluster
constituent ions.
The Coulomb explosion imaging technique is utilized inorder to expand the space size of the 3-MeV C3+ ion fromangstrom- to millimeter-size in our system, which isconsisted of the thin carbon foil and a screen of a luminous
type of multi-channel plate. It was required to evaluate amixing degree of cluster structures of triangular one andlinear one by the scattering effects inside the foil, in order toestimate the structure. We developed, for performing that
evaluation, a Monte-Carlo particle trajectory simulation
code. Initial positions of each constituent ion are assumed tofollow a lateral straggling distribution, by the scattering
effects inside the foil, with two dimensional Gaussian
distribution with 0.4 angstrom in half width at half
maximum on the rear-surface of the foil. The lateralstraggling distribution is experimentally measured using 1MeV C+ ion beam for the foil. In case of a C3 cluster, centre
B

R

Fig.1. A distribution of the ratio of triangular structure
to all data points is plotted in S2-S3 plane.
The distribution is constructed form all calculated data
points for all charge state combination, +1 ~ +4, with acharge fraction measured in our experiment.

points of distributions compose a straight line or an
equilateral triangle with the same atomic separation
distances of 1.2 angstrom. It is also assumed that the cluster
plane of triangular cluster and the chain of linear one areperpendicular to the incident direction of the cluster.
Figure 1 shows distribution of the ratio of triangular ions
toward the sum of both ions on a screen, 190 mm awayfrom the foil, with a reduced relative length S2 and S3: ,where di is a respective distance from a barycentre of threeconstituent ions to i-th constituent ion positions. This
reduction enables us to classify structure in a unite plane forall charge state combinations. Value zero in the distribution
indicates that there is no data point for the triangularstructure in that region. Unity indicates only triangular ionsexist, and smaller value corresponds to a larger fraction of
linear ions. We, from the calculation, obtained the tendency
that the triangular ions are concentrated into a centre
position on this plane, and the linear ions are dispersed
toward three edge regions, even if different charge states
contains in a combination. This characteristic enables us toclassify each structure inside or outside of the circularregions with radii R.
The dependence of the accuracy on the radii was also
calculated and applied for the decision of the radii. We,
finally, evaluate the accuracy of our measurement as 70 ％and 90 %, for triangular and linear structures respectively,
when Rin = 0.67 and Rout = 1.75 for triangular and linear
structures, respectively.
In conclusion, we developed the evaluation method forour charge state and cluster structure measurement system,
based on the Monte-Carlo particle trajectory simulation.
The calculation results also provide us a criterion for the
structure classification, R, with accuracy. The relation
between the charge state and the structure, classified using
these radii, qualitatively agrees with the one theoretically
predicted by Kaneko2).
References
1) A. Chiba, Y. Saitoh and S. Tajima, Nucl. Instrum. Meth.
B 232 (2005) 32.
2) T. Kaneko, Phys. Rev. A, 66 (2002) 052901.

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JAEA-Review 2007-060

4-42 Study of Secondary Ion Emission from HOPG
Target Bombarded by Fast Cluster Ion Beams
a)

a)

a)

b)

b)

b)

b)

H. Shibata , H. Tsuchida , A. Itoh , Y. Saitoh , A. Chiba , M. Adachi , T. Kamiya ,b)c)W. Yokota and K. Narumia)b)

Graduate School of Engineering, Kyoto University, Department of Advanced Radiationc)Technology, TARRI, JAEA, Advanced Science Research Center, JAEA

Recently the interaction of fast (MeV) cluster ions with solids has attracted attention in basic physics and application fields.
Fast cluster ion bombardment causes nonlinear effect or synergetic effect, which is unusual for single atom collision withsolid targets. A time of flight (TOF) mass spectrometer combined with pulsed fast cluster ion beams which were produced by
the TIARA tandem accelerator was used for a secondary ion measurement. In this report we present some results of positive
and negative secondary ion measurement from a highly oriented pyrolytic graphite (HOPG) target bombarded with carbon,
aluminum and gold cluster ions.
高速（高エネルギー）クラスターイオンと物質との相互作用では単原子イオンの数の集合体として線形的に振る舞うのではなく、個数以上、あるいは個数以下の非線形的な効果を与える。二次荷電粒子放出の収量や二次イオン放出スペクトルの測定を通して、高速ク
ラスターイオン照射の特徴を調べることが本研究の目的である。H18 年度は直線飛行時間型(TOF)質量分析器を用いて炭素、アルミニウム及び金クラスターイオ
ンと HOPG (Highly Oriented Pyrolytic Graphite: 高配向性熱分解炭素) 標的との衝突で放出される正負の二次イオン測定を行ったので報告する。
本実験に用いたクラスターイオンはエネルギー0.5
MeV/atom （ 〜 42 keV/u ） の C1+ 〜 C8+ イ オ ン 、 0.675
MeV/atom（〜25 keV/u）のAl1+〜Al4+イオン及び 1.67
MeV/atom（〜8.5 keV/u）のAu+〜Au3+イオンである。
同種のクラスターイオンで核子当たりのエネルギーを広範囲に変えることができることが望ましいのであるが、加速器の制約上不可能なので、加速可能な粒子を変えることで核子当たりのエネルギーを変更し比較した。
標的試料にはHOPGを用いた。HOPG試料は層状に剥がすことができ新しい表面を測定に使えるので他の試料に比べて不純物の吸着が少ないと考えられる。それでも相当不純物（例えば、水、ナトリウムなど）が観測されるので、ECRイオン源からのArビーム照射により表面のクリーニングを行ったTOFスペクトルの計測
はイオンビームをパルス化し、TAC（時間波高変換）を用いる方法により行われた1)。核子当たりのエネル
ギーはBohr速度（〜25 ｋeV/u）とその前後を選び、放出正負二次イオンの全収量（水素を除く）の入射クラスターサイズに対する依存性を比較した。AlやAuクラスターイオン照射に対して放出二次イオン
0.5MeV/atom (~42keV/u) C

10 3

10

質量スペクトルはそれほど変わらず、あまり大きなサイズの放出クラスターイオンは観測されていない。一方、Cクラスターの場合では、大きなサイズのクラスターが正、負二次イオン共に観測されており、炭素-炭素衝突における特異性が考えられる。 図１はC（左図）、Al（中央）及びAuクラスターイオン（右図）をHOPGに照射した際に放出された二次イオンで水素を除いた正負イオ
ンの全収量のC1+、Al1+ 及びAu1+イオン照射における正イオン全収量に対する比をプロットしたものである（C1+、Al1+及びAu1+照射における正イオン放出の全収量をそれぞれ 1 とした）。図中のLinear relationは収量がクラスターの個数に比例している場合である。
図からわかるように三者の入射粒子について比較してみると、Au の場合、正負イオンの収量はクラスター
サイズに余り依存せずほぼ一定で、負の非線形性を示している。一方、C 及び Al の場合はクラスターサイズに対し、ほぼ指数的に増加し、正の非線形性を示している。
すべての入射クラスターについて、負イオンの収量は正イオンの数倍から数 10 倍になっていて、この傾向はエネルギーに関わらず同様である。この理由は未だ明らかではない。
二次イオン放出現象においては、イオンの速度がBohr
速度以下の低速領域では、核的衝突が支配的でクラスターイオンでは負の非線形性が、またBohr 速度以上の高速領域では電子的衝突が支配的で正の非線形性が表れることが理論的に知られており2)、今回の実験では定性
的には理論と同じ結果になっている。
References
1) Shibata et al., TIARA Annual Report 2005 (2007) 177.
2) P.Sigmund et al., Nucl. Instrum. Meth. B112 (1996) 1.

0.675MeV/atom (~25keV/u) Al

3

10

1.67MeV/atom (~8.5keV/u) Au

2

Negative ion

Ratio of yields

Ratio of yields

10 2

Positive ion

10 1

10

2

10

1

Ratio of yields

Negative ion

Negative ion

Positive ion

10

1

10

0

10

-1

LinearLinearPositive ion

Linear relation

10 0

10
0

2

4

6

Incident cluster ion Cn

8

10

0

0

1
2
3
4
Incident cluster ion size Al(n)

5

0

1

2

3

4

5

Incident cluster ion Au(n)Fig.1. The ratio of yields of positive (●) and negative secondary ions (▲) emitted from HOPG target bombarded withcarbon (left hand side), aluminum (middle) and gold (right hand side) incident ions. The yield of positive secondary ionsbombarded by with C1+, Al1+ or Au1+ ion is unity.

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JAEA-Review 2007-060

4-43 Secondary Ion Emission from Polycarbonate
upon Cluster Ion Impacts
a)

b)

b)

b)

K. Hirata , Y. Saitoh , A. Chiba , M. Adachi , K. Narumia)c)and W. Yokotab)b)National Institute of Advanced Industrial Science and Technology (AIST), Department ofc)Advanced Radiation Technology, TARRI, JAEA, Advanced Science Research Center, JAEA
Secondary ions are ejected from the surface when the
primary ions bombard the target.
Cluster ion
bombardments give different secondary ion emission yields
from those for monoatomic ions because of their peculiar
irradiation effect. We have developed a time-of-flight(TOF) secondary ion mass spectroscopy using cluster ion
impacts, and applied it to various samples1-3). In this paper,
we report secondary ion emission from polycarbonate (PC)upon cluster ion impacts.
Positive secondary ion (P-SI) TOF measurements foramorphous PC films with a thickness of 100μm were
performed with a linear type TOF mass analyzer using
pulsed monoatomic and cluster ion beams produced by a 3
MV tandem accelerator of the TIARA1-3). A schematic
diagram of the experimental arrangement is shown in Fig. 1.
Pulsed 0.5 MeV/atom-C1+ and C8+ beams were injected into
the sample with an incident beam angle of 45º relative to thesample surface. P-SIs accelerated between the sample anda TOF drift tube flew in the tube before hitting a
40mm-diameter microchannel plate (MCP). The TOF
spectra recorded in a multi-channel analyzer (MCA) weretransferred to a computer. Several improvements weremade in the TOF system detailed in our previous paper1) :(1) the mass resolution was improved by shortening ahalf-width of the pulsed incident ion beam to ca. 0.1μs andextending a length of the TOF drift tube, (2) the SI
transmission efficiency of the analyzer was enhanced byinserting an electrostatic lens with transmission grids
between an extractor grid and the MCP. The TOF
measurements were performed at a pressure below 3×10-8
Torr and a fresh sample was used for each measurement.
Figure 2 shows the P-SI TOF spectra from m/z (mass tocharge ratio)=20 to 60 of PC for (a) 0.5 MeV C1+ (0.5
MeV/atom C1+), and (b) 4.0 MeV C8+ (0.5 MeV/atom C8+),
respectively. The major peaks observed in Fig.2 can be
attributed to hydrocarbon fragments C2Hm+ (C2H3+: m/z=27,
and C2H5+: m/z=29), C3Hm+ (C3H3+: m/z=39, C3H5+: m/z=41,
and C3H7+: m/z=43), and C4Hm+ (C4H3+: m/z=51, C4H5+:
m/z=53, C4H7+: m/z=55, and C4H9+: m/z=57).
We note that the relative intensities of the fragments aredifferent between C1+ and C8+ impacts although the PC
samples are bombarded with the primary ions of the sameelement with the same velocity. Implanted ions lose theirkinetic energy by interaction with the target. Depending
strongly on the local density of energy deposited by the
implanted ion, the target molecule may be fragmented and afraction of the fragments is emitted as secondary ions. The
local density of the energy deposited at the near surface due

to C8+ impact is larger than that due to C1+ impact because
constituent atoms originating from the same cluster
simultaneously transfer their kinetic energy to a small areaof the target surface. The higher deposited energy density
makes the fragmentation process for C8+ different from thatfor C1+; this difference provides the different positions andrelative intensities of some fragments between the C1+ andC8+ impacts.
In conclusion, the cluster ion impact provides different
relative P-SI intensities for PC from those for the impact ofthe monoatomic ion with the same element and velocity.
References
1) K. Hirata, Y. Saitoh, A. Chiba, K. Narumi, Y.
Kobayashi, and K. Arakawa, Appl. Phys. Lett., 83,(2003) 4872.
2) K. Hirata, Y. Saitoh, A. Chiba, K. Narumi, Y.
Kobayashi, and Y. Ohara, Appl. Phys. Lett., 86, (2005)
044105.
3) K. Hirata, Y. Saitoh, A.Chiba, K. Narumi, Y.
Kobayashi, and T. Kamiya, JAERI-Review, 2006-042(2007) 179.

Fig. 1 Schematic diagram of the set-up.

Fig. 2 P-SI TOF spectra of PC for (a) 0.5 MeV C1+ (0.5
MeV/atom C1+), and (b) 4.0 MeV C8+ (0.5 MeV/atom C8+).

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JAEA-Review 2007-060

4-44 Amorphization of Si Single Crystals by
Au Cluster-ion Irradiation
a)

a)

a)

b)

c)

A. Iwase , T. Nakatani , F. Hori , R. Oshima , Y. Saitoh , A. Chiba
and M. Adachi c)c), K. Narumid)a)Department of Materials Science, Osaka Prefecture University,b)
Osaka Nuclear Science Association,c)
Department of Advanced Radiation Technology, TARRI, JAEAd)Advanced Science Research Center, JAEA
Si single crystals were irradiated with Au cluster ions, and the amorphization of the crystal was observed by means of atransmission electron microscope. The experimental result shows that the degree of amorphization strongly depends on thesize of Au cluster ions.
原子が複数個の化学結合状態を形成して電荷を帯
びた、いわゆるクラスターイオンを高エネルギーに加速して物質に照射すると、単原子イオンを同じ個数だ
け照射した場合と異なる効果が期待される。それは、ある領域に原子複数個に対応するエネルギーが同時に散逸されるためである。前報では、Si単結晶をAu
２ 、Au ３ クラスターイオンで照射し、透過型電子顕微
鏡（TEM）で欠陥集合体を観察した結果を示した。それによると、Au原子の個数を同数照射したにもかかわらず、クラスターサイズが増加するにつれて観察される欠陥集合体の数やサイズが増加することが示された。これらの結果は、クラスターイオン照射量が少ない場合の結果である。今回は、照射量が多いとき、Siにどのようなクラスター効果が現れるかを調べた。
ターゲットには１１１方位のSi単結晶を用いた。あらかじめTEM観察用に薄膜化した試料をTIARAタン
デム加速器により、１原子あたり 1.66 MeVのAu １ イ
オン、Au 2 イオン、Au 3 イオンを室温で照射した。クラスター効果をクリアに見るために、照射されたAu
原子の個数が一定になるような照射量を用いた。TEMにより照射後の試料の電子回折パターンを観測した。
照射量が比較的小さい 1x10 13 Au/cm 2 の場合では、Au 1 、Au ２ イオンを照射したときはSi結晶の乱れは回折パ
ターンからは観察されなかったが、Au ３ クラスターイ
オン照射では、結晶の一部が非晶質化したことを示す
ハローが見られた。照射量が 2x10 13 Au/cm2 と少し多くなるとAu 3 クラスターイオンだけでなくAu 2 クラスターイオン照射の場合でも非晶質化が起こった。この結果を図１に示す。照射量をさらに多くして6x10 13 Au/cm2 とすると、クラスターサイズによらず、すべての照射で非晶質化が見られた。

本実験の結果は、予測したように、クラスターイ
オンは物質のある領域へ高密度のエネルギー付与を起こし、今回の場合は、それは、単原子イオン照射の場合よりも低照射量での非晶質化をもたらしたと考えられる。
Reference
1) A.Iwase et al., JAEA-Review 2006-042 (2007) 178

(a)

Fig.1

－ 186 －

(b)(c)
Electron ditfraction patterns for Si single
crystals irradiated with Au clster ions(a)Au 1 , (b)Au 2 , (c)Au 3 . Irradiation fluence is 2
×10 13 Au/cm2

JAEA-Review 2007-060

4-45 Double Differential Cross Section
for Neutron Production of Beryllium
a)

a)

a)

b)

Y. Iwamoto , N. Matsuda , Y. Sakamoto , K. Ochiai ,c)c)c)Y. Nakane , H. Nakashima and T. Shibataa)b)

Nuclear Science and Engineering Directorate, JAEA, Fusion Research and Developmentc)Directorate, JAEA, J-PARC Center, JAEA

For boron neutron captured therapy (BNCT), there is acandidate as a accelerator neutron source for the use of
Fixed Field Alternating Gradient (FFAG) ring, in which
protons with the energy of about 10 MeV are circulated.
In this source, thin beryllium will be used as a target
material. Neutron production yields, its energy spectra andangular distributions from the thin beryllium bombarded byprotons of about 10 MeV have not been measured
systematically and there is no simulation code to estimate
exactly these items. In this work, neutron spectra and its
angular distributions from the beryllium target bombarded
by protons were measured for the characterization ofneutron source intensity, source term of shielding
calculation and development of simulation code including of
PHITS code.1)
Measurements were performed at the No.1 heavy ion
irradiation room of AVF cyclotron in TIARA. Neutronenergy spectra were obtained by the time-of-flight method
using the two NE213 organic liquid scintillation detectors
with 5.08-cm-diameter and 5.08-cm-thickness.
The
thickness of beryllium target in the vacuumed chamber is 15
μm which is corresponding to the energy loss of 940 keV
for 10 MeV protons. The neutrons and photons emitted
from a beam dump, in which the transmitted protons
through the target are stopped, are shielded by iron andparaffin blocks settled between detectors and the beam
dump.

Fig.1 Double differential cross section for neutron
production toward 15 degree from thin beryllium
bombarded by 10 MeV protons. Bold line presents
the evaluated values in ENDF/B-VII.

Figure 1 shows the neutron production double differential
cross section for the energy above 0.8 MeV toward 15
degree direction compared with values of Evaluated Nuclear
Data File, ENDF/B-VII. Peak energies and values of thecross section are the almost same between measured andevaluated ones. Two peaks in the measurements arecorresponding to the energy levels of the ground state andthe first excited state, 2.4 MeV level. 2) For the evaluatedspectrum, there is a level corresponding to energy of 1.4
MeV, but such a peak is not appeared in observation.
Similar tendency is observed in the neutron spectra of otherdirection angles.
Figure 2 shows the angular dependence of neutron
production yields. The term of “Two peaks” presents theintegrated neutron yield with the energy region above 4
MeV including two peaks, “Low energy” presents thatwith the energy region below 4 MeV, and “Total” presents
the sum of “Two peaks” and “Low energy”. As three
types of neutron production yields get sharply decreasing
with backward angles above 45 degree, the irradiation
position of the patients should be forward direction below
45 degree to secure the neutron intensity for radiation
therapy.
References
1) H. Iwase, et al., J. Nucl. Sci. Technol. 39 (2002) 1142.
2) M.W.McNaughton, et al., Nucl. Instrum. Method 130(1975) 555.

Fig.2 Angular dependence of integrated neutron yield withthree different energy regions.

－ 187 －

JAEA-Review 2007-060

4-46 Development of Dose Monitor Applicable toWide-energy Neutrona)a)A. Endo , T. Sato , D. Satoha)a)and H. Kanekob)b)Division of Environment and Radiation Sciences, NSED, JAEA, Department of Advanced
Radiation Technology, TARRI, JAEA

Workers in high-energy accelerator facilities, such as
J-PARC, are potentially exposed to high-energy neutrons,
photons and muons because of their high penetrability inradiation shielding. Measurement of doses given by theseparticles is therefore of great importance for assuring
radiation safety in the accelerator facilities. None of theexisting survey instruments is however able to measuredoses given by all of these particles. The authors havedeveloped a new radiation dose monitor, designated as
DARWIN (Dose monitoring system Applicable to various
Radiations with WIde energy raNges), for real-timemonitoring of doses in workspaces and surrounding
environments of high-energy accelerator facilities1). In thefiscal year 2006, we have measured doses in various
radiation fields in order to demonstrate the applicability of
DARWIN.
Figure 1 depicts the time-dependence of neutron dose
rates measured with DARWIN in the Light Ion Room No.3
of
TIARA, together with that of the beam current of thecyclotron. Quasi-monoenergetic neutrons of 60MeV weregenerated by the 7Li(p, n) reaction in the LC0 course andthen transported to the Light Ion Room No.3. The time
profile of neutron dose rates measured by DARWIN is
consistent with that of the beam current. It was confirmedthat the measured dose rates agree with the estimated dose
rates from the neutron spectrum in the field. These results
indicate the rapid response and reliability of DARWIN.
Figure 2 shows the measured dose rates with DARWIN in
comparison with the corresponding estimated values invarious fields. The measurements were performed in 1)
TIARA, 2) HIMAC at the National Institute of Radiological
Sciences, 3) Los Alamos Neutron Science Center(LANSCE), and 4) the neutron fields of 252Cf and 241Am–Be
sources in the Facility of Radiation Standard (FRS) at JAEA.
Natural background dose rates of neutron from cosmic-rays
were also measured in Tokai-mura and Los Alamos andthen compared with the estimated values calculated by
EXPACS2), EXcel-based Program for calculating
Atmospheric Cosmic-ray Spectrum. Excellent agreement
can be found between the measured and estimated dose rates
over wide dose rates.
For further investigation concerning the sensitivity of
DARWIN, the background neutron dose rates in
Tokai-mura were measured simultaneously with DARWIN
and a conventional rem-counter (TPS-451, Aloka). It was
found that DARWIN needs only 20 min to obtain the datawith a statistical error within 10%, while the rem-counter
needs ∼ 5 h. This result clarifies that one order of magnitude
for difference in the sensitivity for neutron radiation lies
between DARWIN and the rem-counter. With this property,
DARWIN enables us to monitor small fluctuations ofneutron dose rates near the background level.
References
1) T. Sato et al., J. Nucl. Sci. Technol. 42 (2005) 768.
2) http://www.jaea.go.jp/04/nsed/ers/radiation/rpro/3) EXPACS/expacs.html

Fig.1 Relation between the dose rates measured with Fig.2 Measured dose rates with DARWIN in comparison
DARWIN in the Light Ion Room No.3 of TIARA andwith the corresponding estimated values in various
the beam current of the cyclotron.
radiation fields.

－ 188 －

JAEA-Review 2007-060

4-47 Development of a Detector for Absolute Measurement of
Neutron Fluence in Quasi-monoenergetic Neutron
Calibration Fields of High Energies
a)

a)

a)

a)

a)

b)

Y. Shikaze , Y. Tanimura , J. Saegusa , M. Tsutsumi , Y. Yamaguchi , H. Harano ,b)c)T. Matsumoto and H. Kanekoa)b)Department of Radiation Protection, NSRI, JAEA, National Metrology Institute of Japan,c)National Institute of Advanced Industrial Science and Technology, Department of Advanced
Radiation Technology, TARRI, JAEA
In facilities of high intensity proton accelerator, it isimportant for radiation control to measure the dose for highenergy neutrons penetrating the shielding materials. Highenergy neutron calibration fields are necessary for accurate
dose measurements to appropriately calibrate the monitor
and the dosemeter used there. For the neutron fields above
20 MeV, however, the international standards for theneutron fields and relevant calibration techniques have notbeen
established.
Therefore,
by
using
the
quasi-monoenergetic neutron irradiation fields of several
tens of MeV at TIARA1) of Takasaki Advanced Radiation
Research Institute, Japan Atomic Energy Agency (JAEA),
the development of the calibration fields for such highenergies has been in progress toward the standard fields.
Neutron fluence of peak region is one of the most importantcharacteristics
ofthecalibration
fieldswithquasi-monoenergetic spectrum. For absolute measurementof the peak neutron fluence, a proton recoil telescope (PRT)
has been developed.
The PRT consists of a Si semi-conductor detector tomeasure ionization energy loss (ΔE) and an organic liquid
scintillation detector to measure full energy (E) of recoil
protons. The Si detector has the sensitive area of 3000 mm2
with a fully depletion layer of 300-μm. The liquid
scintillator (BC-501A type) has the sensitive volume of
7.62-cm both in diameter and in length. Its performance wastested in the neutron fields, where neutrons were producedin the nuclear reaction of 7Li targets with 50, 65 and 80
MeV protons. The proton energies correspond to neutrons
with the peak energy of 45, 60 and 75 MeV, respectively.
The measurement is based on the detection of the recoil
protons produced in a polyethylene converter by theincident neutrons. For the precise measurement of the peakfluence based on the n-p elastic scattering cross-section, theunwanted protons from carbon in converter material(C(n,xp)) must be subtracted. Therefore, measurement withgraphite converter was also performed. The PRT was set on
the neutron beam axis at the two different distances from thetarget (5.585 and 12.905 m). The brass shadow bar (8-cm india., 50-cm in length) was used to avoid the neutrons
directly incident to the detector. The thin annular converters
with inner diameters of 8.8-cm were applied. Since thecollimated neutron irradiation fields at TIARA enlarge withincreasing distance from the target2), outer diameters of theannular converters were appropriately selected to use theirradiation fields effectively.
Recoil protons were clearly identified in the obtained ΔE
v.s. E distribution as shown in Figure 1. Energy resolutionof the Si detector was 24.7 % for recoil protons
corresponding to peak neutrons with 45 MeV, and wasenough for the separation of protons from background
deuterons. By selecting the recoil protons, energy spectra of
the recoil protons were obtained for the two different
converter materials. After the compensation for the
backgrounds from carbon and air nuclei, the recoil protonenergy spectra only for n-p elastic scattering were derived.
From the results for the three neutron fields with 45, 60 and
75 MeV peak, it was confirmed that detection efficiency
was enough for the absolute measurements of peak neutron
fluence both at 5.585 and 12.905 m from the target.
References
1) M. Baba et al., Nucl. Instr. Meth. A 428 (1999) 454.
2) Y. Shikaze et al., JAEA-Review 2005-001 (2006) 337.

Fig.1 Energy loss (ΔE) measured by the Si detector v.s.
Energy (E) measured by the organic liquid
scintillation detector for measurement with
polyethylene converter (neutrons with 45 MeV peak).

－ 189 －

JAEA-Review 2007-060

4-48 Development of Focusing High-energy Heavy Ion
Microbeam Technology and Its Application
a,b)

a)

b,a)

a)

a)

a)

T. Kamiya , T. Satoh , M. Oikawa , S. Okumura , S. Kurashima , N. Miyawaki ,
a)
a)
c)
c)
c)
d)
H. Kashiwagi , W. Yokota , T. Funayama , T. Sakashita , S. Wada , T. Hirao ,
d)
d)
c,b)
d)
S. Onoda , K. Mishima , Y. Kobayashi
and T. Ohshimaa)d)

Department of Advanced Radiation Technology, TARRI, JAEA, 21st Century COE programc)
Graduate school of medicine, Gunma University, Radiation-Applied Biology Division, QuBS,d)
JAEA, Environment and Industrial Materials Research Division, QuBS, JAEA

A focusing type high-energy heavy ion microbeam
system with a sub-micron level spatial resolution had been
established in the vacuum system1). Now an end-station wasdeveloped to extract microbeams out to the atmospherethrough a thin film, so as to evaluate response of specificpart of intracellular structure such as a cell nucleus, acytoplasm or cell wall with a high spatial resolution of 1 μm
level.
Figure 1 shows the schematic draw of an end-station,
which was connected with a lower plate of the Q-lens frame
through a flange of the ICF-70 standard, was simply
designed to evaluate the beam size at the beam exit window
on the atmosphere, and to perform the preliminary
microbeam applications.
It has flexibility of thebellows-seal and positioning mechanism with a movable
range of ±12.5mm in each direction by X/Y stage withstepping motor drive. The manifold connected to thebellows is 42mm in outer diameter, 32mm in inner diameter,and 49mm in length. It has two ports for a secondary
electron detector; one is for a light-guide connected to aring-type plastic scintillator set at a height of 14 mm fromthe under-surface of the manifold to detect scintillation bysecondary electron from the sample, and the other is forhigh-voltage supply on a moralized surface of thescintillator. On the bottom of the manifold, there are threepenetration holes with diameters of 1 mm, 2 mm and 3 mm,
respectively. A copper-grid (1000 lines per inch) standard
sample, which was utilized to measure the beam size by

secondary electronic mapping, and a plastic scintillator film
to monitor beam spot profile at the target were attachedoutside of the 1-mm and 3-mm holes, respectively. The
2-mm hole was a blank for use of irradiation experiments.
All holes together with the grid and the film were covered
with a polyimide thin film of 7.5 μm thickness to keep thevacuum inside of the chamber. The flat bottom of the
manifold was designed, so that an air-gap between the film
and sample should be as small as possible in the irradiation
set-up for the experiments.
Figure 2 shows a typical secondary electron image of thegrid at the beam exit window obtained with this new setup
using a microbeam of 260MeV Ne ion. The average beam
size was obtained at about 2 μm from the peak fitting for thesecondary electron yield curves along lines for X and Y
directions, respectively, so far. The spatial resolution of
the beam at the sample in the atmosphere can be
deteriorated by scattering in the film and the air gas.
Further work will focus onto reliability in forming thehigher spatial resolution microbeam, which depends onstabilization of a beam current from a cyclotron, as well as
on establishment of automated single ion hit system.
Reference
1) M. Oikawa, , T. Kamiya, M. Fukuda, S. Okumura, H.
Inoue, S. Masuno, S. Umemiya, Y.Oshiyama and Y.
Taira, Nucl. Instr. and Meth. B, 20 54 (2003).

25 μm

Fig.1 Schematic view of the end-station of the high-energy
heavy-ion microbeam system.

Fig.2 Typical secondary electron image of copper
mesh in gray-scale obtained by a 260 MeV Ne
microbeam scanning. The mesh has 6-μm
width lines and 19 μm－ 190 －

JAEA-Review 2007-060

4-49 Development of Irradiation Position Control Techniques
for Ion Microsurgery Using an Ion Beam Induced
Fluorescent Analysis
a,b,d)

a,b,d)

b)

b)

c)

d)

H. Shimada, M. Oikawa, T. Satoh , S. Okumura , M. Taguchi , T. Sato ,
d)
d)
e)
a,b)
d)
a,d,e)
Y. Horiuchi , H. Katoh , K. Yusa , T. Kamaiya , S. Kishi , T. Nakano
a,b,d,e)and K. Arakawa
a)b)

21st Century COE Program, Graduate School of Medicine, Gunma University, Department ofc)Advanced Radiation Technology, TARRI, JAEA, Environment and Industrial Materials Researchd)Division, QuBS, JAEA, Department of Medicine, Graduate School of Medicine, Gunma University,e)Gunma University Heavy Ion Medical Center, Gunma University,
The heavy ions have unique characteristics of high energy transfer localized in the vicinity of almost straightforward tracks.
The heavy ions are suitable for the treatment of small tumors with the size of several millimeters or less. This research aims
at developing an innovative microsurgery treatment system, using the carbon-ion pencil beam, for AMD (age-related
macular degeneration). The AMD treatment system has been studied using the carbon-ion pencil beam system.
TIARA 施設の AVF サイクロトロン・HA コースを用いて行った。空気飽和した眼底蛍光造影剤水溶液（ICG およびフルオレセイン；Fl）に、炭素イオン
ビーム（C5+-220 MeV, C6+-320 MeV）を照射し、眼底
蛍光造影剤水溶液からの発光スペクトルおよび発光画像を観察した。サンプルの濃度は標準的な人体に投与した際の最高血中濃度（1.0 x 10-2 mg/mL，1.3 x 10-5M）に調整した。
その結果、重粒子線照射による眼底蛍光造影剤からの発光画像および発光スペクトルが取得できた。Fig.1にイオンビーム照射直後に測定したFlの蛍光スペクト
ルを示す。光励起に比べ、発光波長はほぼ同じである
が、Flの蛍光量子収率（0.98）に対して発光強度が非常に微弱である。このため、発光色素や検出系の再検討が必要である。

1500
Photon Counts

我々は、群馬大学21世紀COEプログラム「加速器テクノロジーによる医学・生物学研究」の主要なテーマのひとつとして、原子力機構・高崎研と連携して、高精度炭素イオンマイクロサージェリー技術の開発を行っている。従来のX線やγ線照射などよりも生物への照射効果の大きな重粒子線を用い、エネルギー付与の大きなブラッグピークを利用して狭小領域の患部に集中的にエネルギー付与し、選択的かつ集中的に治療を行うことを目指している。
本研究では、難病にも指定されている眼底疾患のひとつである加齢黄斑変性症を治療想定症例として、高精度炭素イオンマイクロサージェリー技術の検討を進めている。黄斑部は網膜の中で最も視神経が集中する
非常に重要な部位であり、この部位周辺に網膜下の狭小領域に新生血管が発生し網膜を歪めてしまうのが加
齢黄斑変性症(以下AMD)である。症状として、非可逆的かつ高度な視力低下や視野の中心が歪む変視症の症状が見られ、最悪の場合、視野の中心が完全に失われてしまう。推定の患者数は約40万人で、その予備群も含めると約600万人にもなり、今後、超高齢化社会を迎える我が国において、無視できない患者数である。
これまで、ビーム径0.1～5 mmφのペンシルビームを形成するための光学計算、構成機器およびその最適配置に関する検討を行ってきた。1) 今回、照射位置決め法として、眼底蛍光造影剤を用いた重イオンビーム誘起蛍光法を考案し、重イオンビーム誘起蛍光計測シス
テムを用いて実験を行うとともに、照射照準位置制御技術の検討を行った。
現在、眼底の狭小・微細領域にある患部を正確に3次元精密照射するために必要な照射照準制御技術の開発が最大の課題となっている。その方法として、眼底患部に注入した眼底蛍光造影剤（インドシアニング
リーン；ICG）に、重粒子線を照射し、飛程をレンジ
シフタで微調整しながら、ICGからの発光を専用特殊眼底カメラ等を用いて観測する。その発光画像を解析
して照射位置の決定を行う。
眼底蛍光造影剤への照射実験は原子力機構・高崎研

1000

500

0

500

550

600

Wavelength / nm

Fig.1

The fluorescence spectrum of fluorescein in water at
293 K obtained to C5+ beam irradiation.

Reference
1) H. Shimada, et al., JAEA Takasaki Ann. Rep. 2005,

JAEA-Review 2006-042 (2007) 186.

－ 191 －

JAEA-Review 2007-060

4-50 Development of the Cyclotron System for Advanced
Irradiation
N. Miyawaki, S. Okumura, S. Kurashima, Y. Yuri, T. Yuyama, T. Ishizaka, H. Kashiwagi,
K. Yoshida, I. Ishibori, T. Agematsu, T. Nara and W. Yokota
Department of Advanced Radiation Technology, TARRI, JAEA
Microbeam Formation
For production of a focused heavy-ion microbeam1) in the
JAEA AVF cyclotron, the beam energy spread has been
improved by optimizing the operating parameters including
flat-top (FT) acceleration2). In the case of a 260 MeV-20Ne7+
beam, the energy spread of 0.05 % was achieved and both of
the spatial resolution and the hitting accuracy were
evaluated at less than 1 μm3). In the next place, the FT
acceleration of a 220 MeV-12C5+ beam was tested. The beamphase in the FT acceleration was controlled by a pair ofphase defining slits in the center region of the cyclotron.
The beam current was as high as 0.6 μA when both of thesinusoidal and the saw-tooth waveform bunchers were turnon. As shown in Fig. 1, we observed the clear turnseparation of the beam intensity distribution with thedeflector probe. The extraction efficiency at the deflector
was successfully increased up to 98 % with the single-turn
extraction.
In order to reduce the sources that cause instability of ion
beam current, we have exchanged the temperature control
system of magnet power supplies. By the temperature
control of the feedback control circuit with Peltier devices, abeam current fluctuation caused by power supplies was
significantly reduced.
Uniform Irradiation Using Multipole Magnets
We are now developing the uniform-beam irradiation
system using multipole magnets with the aim of the advancein uniform-irradiation technique. It enables us to obtain
homogeneous irradiation effects on over a sample with alarge area or on a large number of samples simultaneously
without scanning the beam.
We have theoretically studied the beam dynamics under
0.6
12 5+

220 MeV C
FT ONBeam Current (uA)

0.5
0.4
0.3
0.2
0.1
0
0

10

20

30
40
50
Deflector Probe Position (mm)6070

Fig.1 Beam intensity distribution measured with thedeflector probe. The final peak, extracted through thedeflector electrodes, was cleared by the FT acceleration.

the nonlinear magnetic fields to produce a beam with auniform transverse intensity profile in the beam transport at
the AVF cyclotron facility4). Although all the odd-ordermultipole magnetic fields are, in theory, required foruniformization of a Gaussian beam, it is practically possible
to produce a uniform beam only with an octupole focusing.
2
Its integrated strength is 1/(εβ 0 tan θ) , where ε is the rms
emittance of the beam, β0 is the beta function at the octupole
magnet, and θ is the betatron phase advance from themagnet to a target. The full width of the resultant uniform is
2π εβ t cos θ , where βt is the beta function at the target.
Based on these formulae, we have optimized the optics ofthe beam line. It is possible to produce a beam with auniform profile of 10 cm square at the target. The effect ofbeam emittance and energy spread on beam uniformization
has also been explored through systematic simulations.
Intensity Control with Beam Attenuators
Beam current control over a very wide range is required
for experiments and beam tuning in the JAEA cyclotron. A
beam attenuator (ATT) to attenuate the beam current
without changing the beam profile is set in the injection lineof the cyclotron. The beam current is controllable in therange of 10-1 to 10-12 by combining the ATT meshes of 10-3,
10-2 and 10-1. It was found that the ATT did not always keep
the beam profile at a target point and did not control the
beam current precisely according to the combination of themeshes. We estimated the beam size at the installation pointof the ATTs with the design value of the emittance.
Influence of combination of the meshes to the beam profile
was also examined by the Gaf film which allows the beamprofile measurement easily. As a result, we realized that theintervals of the meshes were too short at the beamdiagnostic station of IS2, and the spacing of the holes in themesh was too long at that of IS5, which is a waist point in
the beam transport.
References
1) M. Fukuda, et al., Nucl. Instrum. Methods Phys. Res. B
210, 33 (2003).
2) S. Kurashima, et al., Nucl. Instrum. Methods Phys. Res.
B 260, 65 (2007).
3) M. Oikawa, et al., Nucl. Instrum. Methods Phys. Res.
B 260, 85 (2007).
4) Y. Yuri et al., in Proceedings of the 3rd Annual
Meeting of Particle Accelerator Society of Japan andthe 31st Linear Accelerator Meeting in Japan, 913(2006)－ 192 －

JAEA-Review 2007-060

4-51 Development of All-permanent-magnet
ECR Ion Source for the JAEA Cyclotron （Ⅱ）
K. Yoshida , T. Nara , Y. Saitoh and W. Yokota
Department of Advanced Radiation Technology, TARRI, JAEA
We have been developing an all-permanent-magnet type
ECR ion source (LECR) since 2003 to realize the highstability of beam intensity and reduction of the adjustment
time of the JAEA AVF cyclotron1). The magnetic field
distribution of LECR is changeable by an axially moving
the mirror tuning magnets of the extraction and the gas
injection side2). The beam current of LECR increased 10
times as much as that of the original design, and thecontinuous operation became possible by the previous
modification3). In this paper, we report the new modification
for further increase of beam intensity and the result.
In the original design, the entire magnets of LECR can beslide in the axial direction within 60 mm to adjust therelative position of the beam extraction hole against themagnetic field. The vacuum was deteriorated by outgas
from the inner wall of long puller by hit of extracted beam.
It appeared that the distance of 5 mm in the axial direction isenough by experiment. Therefore, we modified design ofthe high-voltage insulation and the joint parts of the plasmachamber, and changed the diameter of einzel lens.
There was a clearance of 2 mm between the plasmachamber and the magnet for the high-voltage insulation
sheet. The inner diameter of the plasma chamber was
extended to increase confinement efficiency by decrease inclearance of 2 mm. The material of a plasma chamber waschanged into oxygen free copper from stainless steel toimprove the cooling efficiency.
A schematic drawing that describes the modification isshown in Fig 1, and the modification is summarized inTable.1.

Table.1 the modification in FY2006
Diameter of plasma chamber(ID)Materials of plasma chamber
Puller length
Diameter of einzel lens

32 mm → 36 mm
SUS316 → C1020
190 mm → 107 mm
25 mm → 48 mm

The improvement of LECR by the modifications is shownin table 2. The beam current of O7+ increased from 0.6 to 1.8µA. A considerable amount of beam loss may takes place inthe analyzing magnet because its chamber inner gap is 54
mm, not enough for beams from an ECR ion source with alarge emittance.
Table.2 The performance of LECR
O4+
O5+
O6+
LECR (original)
2
1
0.6
LECR (2005)
16
15
10
LECR (2006)
44
33
18

We are, therefore, planning to install LECR in an injection
line of the cyclotron with an analyzing magnet whose inner
gap of the chamber is designed 92 mm.
References
1) S. Kurashima, et all, Nucl. Instr. and Meth B,
260(2007)65-70.
2) K.Yoshida, T.Nara, Y.Saitoh, W.Yokota, TIARA annual
report2003 (2004) 316.
3) K.Yoshida, T.Nara, Y.Saitoh, W.Yokota, JAEA
Review2005 (2006) 190.

Φ48mm Einzel lens
107mm Puller

MagnetEinzel lensHexploe

HexpoleHexpoleHexpolePullerBeam extraction
0100

300L/sTMP(instal 2005)

Φ36mm Plasma chamber
200

O7+
<0.01
0.6
1.8

300

Fig.1 The modification of LECR ion source in 2006.

－ 193 －

－ 194 －JAEA-Review 2007-060

4-53 Design of a Compact High-energy Focusing Lens System
Combined with an Acceleration Tube
a)

a)

a)

Y. Ishii , T. Ohokubo , J. Haga , A. Kobayashia)b)

and S. Adachib)b)

Department of Advanced Radiation Technology, TARRI, JAEA, Kobe Steel Ltd

focusing points are formed in the accelerator tube when the
A fine fabrication using high-energy focused proton
N value of 27 and 20 for object points of 300 mm and 500
beams, proton beam writing (PBW), is a promisingmm, respectively. Thereby, the usage of large
technique for development of 3D structures such as opticaldemagnification, that is large N value, provide impossible todevices and high sensitive sensors. High energy focusedirradiate samples.
gaseous ion micro-/nanobeams are formed by the
A 1.7 MeV focused proton with one hundred nm incombination of a MV electrostatic accelerator, a beam line
diameter
could be formed using the schematic design of thewith a high resolution analyzing magnet and a high-energy
compact MV high-energy lens system as shown in Fig.1
focusing ion beam (MeV focused ion beam) system. Sincewith the parameters as listed in Table 1. The beam current at
each component combined in the system is longer than 10 m,
a focusing point is, however, small due to using a small
the total size of its system reaches to several tens of meters.
aperture to inject small beam divergence angle into the
The wide usage of the MeV focused ion beam in various
accelerator tube. The one order smaller divergence beam
researches and development fields is, thereby, difficult due
angle injected into the accelerator tube is required to reduceto the large size of the combination system.
aberrations as compared with the outgoing beam angle of
The acceleration lens system, a series of acceleration
the second acceleration lens. The acceleration lenses with alenses each of which has the both effects of focusing andcontrollable outgoing beam divergence angle areaccelerating ion beams in an electric field, was developed toinvestigating to increase the beam current at the focusing
achieve the demagnification over 1000 in JAEA. The
point. Furthermore, a multicusp ion source has been
focusing potential of the acceleration lens system was so far
developing to increase beam current at the focusing point.
demonstrated by using the keV gaseous ion nanobeam
system and forming the 170 nm H2+ beam at 50 keV1).
1st acceleration lensOn the other hand, a compact 1 MV focused ion beam
Accelerator tube
system (compact 1 MV system) was developed using the
combination of a 1 MV accelerator and a MeV focused ion
beam system with magnetic quadruple lenses in Kobe Steel,LTD (KSL). Beam sizes with several micrometers in
Ion source
diameter are formed using the compact 1 MV system for theinvestigation of material element analysis in various
2nd acceleration lensmaterials using RBS techniques. JAEA in cooperation with
KSL is developing a compact 2 MeV level gaseous ion Fig.1 A schematic design of a compact high-energy
nanobeam system aiming at 100 nm sized special resolution focusing lens systemachieved by combining the acceleration lens system with thecompact 1 MV system.
The MeV high demagnification lens system was designed
Table.1 Parameters of the designusing the acceleration lens system and an acceleration tube
1st accel. lens 2nd accel. lens Accel. tube
in the last year. The basic data of a multicusp ion source
voltage (kV)
5
100
1700
developed for another study were also measured to evaluate-3-3
the conditions of beam current, energy and energy-spread
Incident
1×10
1×10
1×10-4required to its source.
angle (rad)The two kinds of performance of the acceleration lens andOutgoing
2.5×10-2
5.7×10-3
the acceleration tube needs to be investigated to design theangle (rad)compact MV high-energy focusing lens system. The
Magnification -0.0056-0.0391.03
performance data of the acceleration lens was a priori
Beam size
2.2μm
86nm(betwe 92nm
investigated from that of the keV gaseous ion nanobeam
en electrodes)
system.
The relation between focusing point and magnification
was calculated employing Elkind’s equation applying
Referenceaccelerator tube parameters used in the compact 1 MV
1) Y.Ishii, et. al. Nucl. Instr. and Meth. B210(2003)70
accelerator as a function of N value (accelerated beamenergy/injection beam energy). The relation shows that the－ 195 －

JAEA-Review 2007-060

4-54 Micro-machining of Resists on Silicon
by Proton Beam Writing: Part 2(Fabrication of 3-D Structures Using a Negative resist)
a)

a)

a)

b)

b)

b)

N. Uchiya , Y. Furuta , H. Nishikawa , J. Haga , T. Satoh , M. Oikawa ,
b)
b)
b)
c)
T. Ohkubo , Y. Ishii , T. Kamiya and S. Yamamotoa)b)

Department of Electrical Engineering, Shibaura Institute of Technology, Department ofc)Advanced Radiation Technology, TARRI, JAEA, Environment and Industrial Materials
Research Division, QuBS, JAEA

Proton beam writing (PBW) is a direct write technique forthe purpose of micro- or nano-meter sized machining 1). This
technique does not require an expensive mask for patterning
as well as electron beam though the mask is required for the
exposure with UV (EUV) and x-ray. The lateral stragglingof proton beam with energy of MeV order is far smaller
compared with electron beam. The depth of fabrication isreached to several tens of micro-meter in a resist andcontrolled by the beam energy. The PBW is a promisingtechnique for the micro-machining of thick resist andthree-dimensional (3-D) structures with high aspect ratios 2).
In our previous report 3), we confirmed the fabrication of
micro-structures with smooth and vertical side wall by the
PBW on PMMA and SU-8. In this paper we report theresults of fabrication of 3-D structures using two ranges ofproton beams in SU-8 layer controlled by the beam energies.
The micro-meter-sized structures by the PBW wereobserved by a scanning electron microscope (SEM).
We used a layer of negative resist SU-8 (N-02 Wafer,
MEMS CORE) with a thickness of 50 µm on Si wafer.
The resist layer on silicon was exposed by focused proton
beam formed by the micro-beam system in TIARA, JAEA.
The beam size was estimated at about 1 µm in diameterfrom secondary electron images of a commercially available
Ni mesh. The PBW was carried out with a resolution of
8192 x 8192 pixels in an area of 700 x 700 µm2 by anelectrostatic scanner. The projected ranges of proton beam
into the resist layer were controlled by using two different
proton beam energies of 1.2- and 3.0-MeV. The fluence of
protons was controlled ranging from 20 to 80 nC/mm2. 4)
In the first step, irradiation of the proton beam wascarried out at the energy of 3.0 MeV to form posts on thesubstrate with a projected range of more than 50 µm. In thenext step, the irradiation was carried out at the lower energyof 1.2 MeV to bridge across the posts at a depth of 28 µm.
After the development process for 3 minutes using adeveloper for SU-8 and rinse in isopropyl alcohol, thesamples, which were coated with Pt by sputter to avoid
charging, were observed by the SEM.
The fabricated 3-D structures were shown in Fig.1. The
depth of the lines written by 1.2-MeV PBW were 22 µm
from the resist surface that was close to 21 µm estimated by
SRIM simulation 5). The vertical and smooth side wall of theposts was formed by 3.0-MeV PBW. Using this technique,
we demonstrated fabrication of the structure like the Arch of
Triumph showed at Fig. 2.
The controlled ranges of the proton beam by changing thebeam energies enabled us to fabricate the multi-levelstructures in the single resist layer. This shows thecapability of the PBW in the formation of 3-D
high-aspect-ratio structures.
References
1) S. V. Springham et al., Proc. SPIE Int. Soc. Opt. Eng.
3183 (1997) 128.
2) A. A. Bettiol et al., Proc. SPIE Int. Soc. Opt. Eng. 5347
(2004) 255.
3) N. Uchiya et al., TIARA annual report 2005 (2006)
174.
4) N. Uchiya et al., Nucl. Instr. and Meth. B 260 (2007)
405
5) J.F. Ziegler et al, The Stopping and Range of Ions in
Solids, Pergamon Press, New York, 1985.

50 µm
28µm

Fig. 1 SEM image of the grid structure of SU-8
fabricated by PBW of energies of 1.2 and 3.0 MeV.

Fig. 2 SEM image of 3-D structure of SU-8 likethe Arch of Triumph fabricated by PBW atenergies of 1.2 and 3.0 MeV.

－ 196 －

JAEA-Review 2007-060

4-55 Measurement Technique of Two Dimensional DoseDistribution Using B3 Film Dosimeters and a PC-scanner
H. Hanaya, T. Agematsu and T. Kojima
Department of Advanced Radiation Technology, TARRI, JAEA

2. Experimental and result
B3 film dosimeters with and without 200 μm-thickaluminum package were irradiated by 2 MeV electron
beams to doses of 5 - 100 kGy. The irradiated dosimeters
without heat treatment were readout using the image
scanner (Canon LiDE50) with Green color components at
different elapse times after irradiation.
The dose response curves for different elapse time after
irradiation were shown in Fig.1: a) when dosimeters were
kept in the package, and b) when dosimeters were not kept
in the package. Any dose responses increase with dose andtheir curves are similarly linear up to at least 40 kGy. The
dose responses increase with elapse time, but the slopes
become gentle 24 h after irradiation, not depending on theuse of the package.
3. Discussion
The B3 dosimeters show the linear dose response up toat least 40 kGy even used without package. It demonstrates
that the dosimeters are usable also for ion beams having
short penetration range. The dose response increases as afunction of elapse time after irradiation. Such a variation canbe minimized with heat treatment, but it becomes negligible
order (< 3%) 24 h after irradiation without heat treatment.
The combined system with the B3 film dosimeters andan image scanner has a potential to be applied tomeasurement of 2D relative dose distribution of ion beams
in the dose range of a few tens kGy, although further studies
should be done using ion beams instead of electron beams.
References
1) T. Agematsu and H. Hanaya, JAEA Annual Report 2005,
183 (2006).
2) H. Hanaya and T. Agematsu, JAEA Annual Report 2005,
184 (2006).

Converted optical density(Log10(255/value of G reen component)

1.4
After 1 h

1.2

After 24 h

1.0

After 1 week

0.8

After 1 mounth

0.6
0.4
0.2
0.0

0

20

40

60

80

100

Dose [kGy]a) B3 film dosimeters kept in the aluminum package.
0.4
Converted optical density(Log10(255/value of Green componet)

1. Introduction
Measurement of 2D dose distribution in large ion beamirradiation area is one of the indispensable techniques for
R&D in material science and bio-technology using a
cyclotron. Measurement technique for 2D distribution ofrelative ion beam fluence has been developed using
Gaf-chromic films (HD-810) and an image scanner for a
personal computer1). This combined system has advantages
such as costless, easiness of handling and speedy
measurement with high spatial resolution. The measurable
dose using this system is, however, not applicable to doses
above 1200 Gy. The use of B3 film dosimeters (GEX
B3002) was tested instead of Gaf-chromic films to expand
measurable dose range of the combined system to higher
dose region. The B3 dosimeters are commercially available
in the aluminum package but would be used formeasurement of ion beams after removing it, since ion
beams have generally short penetration range. The opticalreadout of B3 dosimeters associates with heat treatment
after irradiation for stabilization of dose response before
readout. In the preliminary study, dose response of B3 films
irradiated in the package by 2 MeV electron beams waslinear up to 100kGy when readout using Green color
component without heat treatment after irradiation 2). Dose
responses of B3 film dosimeters irradiated with and without
package were examined including their stability after
irradiation.

After 1 h
After 24 h

0.3

After 1 week
After 1 monuth

0.2
0.1
0.0

0

10

20

30

40

50

Dose [kGy]b) B3 film dosimeters not kept in the aluminum package.
Fig.1 The dose response of B3 film dosimeters for 2MV
electron beams when readout using the image scannerwith Green color component.

－ 197 －

JAEA-Review 2007-060

4-56 Properties of Radiochromic Film Dosimetersfor Low Energy Electron Beam
a)

a)

b)

H. Seito , T. Kojima , T. Takei , T. Idea)b)

and I. Morib)b)

Department of Advanced Radiation Technology, TARRI, JAEA, IWASAKI ELECTRIC Co., Ltd

0.08

Specific absorbanceIntroduction
Application of low energy electron accelerators (50-300keV) is expanding in the field of radiation processing.
Radiochromic film dosimeters have been used widely bothin the industrial processes and research employing
gamma-rays and electron beams1). These dosimeters havebeen calibrated commonly only for cobalt-60 gamma-rays,
therefore the feasibility of this calibration should be studied
also for their application to low energy electron beams.

0.06

FWT60

0.04

B3

0.02
0
0

Experimental
Two different radiochromic dosimeters were used in thisstudy. One is nylon-based FWT602) with thickness of 10
μm, containing hexahydroxyethyl pararosaniline cyanide
as the radiation-sensitive component. Another is GEX B3
radiochromic film dosimeter3). The B3 radiochromic
dosimeter contains a radiochromic dye precursor ofpararosaniline cyanide dissolved in polyvinyl butyral.
Fundamental properties of these dosimeters were studied
preliminalily for gamma-rays. The gamma-ray irradiation
was carried out using a 60Co plaque source (2.6 PBq) at adose rate of 10 kGy/h, which was measured with theionization chamber periodically calibrated at AIST. Opticaldensity was measured using Hitachi spectrophotometermodel U-3310. Wavelength of 600 nm and 554 nm is used
for dose measurement of FWT60 and B3, respectively.
Results and discussion
Response curves of the two different dosimeters are shownin Fig.1. The dose response of FWT60 is larger than that of
B3. The response curve of FWT60 is nearly linear with dose

20

40

60

Dose (kGy)

Fig.1 Dose response curves of FWT-60 and B3
up to 30 kGy and become sublinear at higher doses, on theother hand, that of B3 is nearly linear with dose up to 60
kGy.
The stability of absorbance is studied both for FWT60
and B3 after irradiation to doses of 15、25、35、45、and 55
kGy, for 1 month. The variation of absorption occurred after
irradiation is less than 2% for both dosimeters showing longshelf-life stability.
These results should be a base for application of theseradiochromic dosimeters to low energy electron beams.
References
1) ISO/ASTM 51275 (2004) Standard Practice for Use of aRadiochromic Film Dosimetry System
2) A. Miller , Riso-M-2401. (1983)
3) A. Miller et al., Radiat. Phys. Chem. 31 (1988) 491－ 198 －

JAEA-Review 2007-060

4-57 Standard Dosimetry of a few MeV Electron and
60
Co Gamma-ray in Radiation Processing
H. Seito , T. Kojima , H. Kaneko and N. Haneda
Department of Advanced Radiation Technology, TARRI, JAEA

Results and discussion on dose intercomparison
The uncertainty associated with the established standard
dose measurement procedure in JAEA has been reviewed.
The total uncertainty in 60Co gamma-ray absorbed dosedelivered by the JAEA calibration system is evaluated to be
2.2%(2σ). The uncertainty of dose measurement using
JAEA alanine/ESR transfer dosimeters is also estimated tobe 3.4%(2 σ ) for 60Co gamma-ray irradiation. A doseintercomparison study in the dose range of 1-50 kGy was
carried out with National Physical Laboratory (NPL) to
confirm our estimated uncertainty, employing transfer
dosimeters: alanine dosimeters and dichromate dosimeters2).
The results of dose intercomparison between JAEA andNPL show good agreement within about 2% in the dose
range of 1-50 kGy. The results assure the uncertainties ingamma-rayabsorbed dose measurement at JAEA using parallel-plate
ionization chamber as a working reference dosimeter andalanine dosimeters as reference transfer dosimeters.

Dose comparison was performed for 2-MeV electrons
employing cellulose triacetate (CTA) and alanine film
dosimeters which were independently calibrated for 2-MeV
electrons and 60Co gamma-rays using the calorimeter andthe ionization chamber systems respectively3). Agreement of
two different dose evaluations was better than 2.0% (1σ) as
shown in Fig 1. These results should enable us to achieve
highly reliable dosimetry for the quality assurance inelectron radiation processing on the basis of gamma-ray
dose standards.

140
estimated dose(kGy)Introduction
The high-dose calibration technique using a parallel-plate
ionization chamber system has been developed in the JAEA
dose calibration facility1). The facility equips two 60Co γ-ray plaque sources covering wide dose-rate range of
5-20000 Gy/h which have overlapping dose-rate region withthat at the National Institute of Advanced Industrial Scienceand Technology (AIST), the national standard dosimetrylaboratory in Japan. Consistency of dose calibration results
at JAEA and those at AIST was verified without additionalcorrection regarding to difference in characteristics ofradiation fields involving current/exposure-rate conversion
coefficients given in the dose rate level of 10-100 Gy/h at
the AIST and high-dose rates of 5-20000 Gy/h at JAEA.

120
100

alanine film
CTA film

80
60
40
20
0

0 20 40 60 80 100 120 140
nominal dose(kGy)

Fig.1 Correspondence of electron dose evaluation(nominal dose) with gamma-ray dose evaluation(estimated dose)
References
1) T. Kojima, H. Tachibana, N. Haneda, H. Kaneko, Y.
Haruyama and R. Tanaka, RADIOISOTOPES 50 (2001)
291
2) T. Kojima, H. Tachibana, N. Haneda, I. Kawashima and
P.H.G. Sharpe, Radiat.Phys.Chem 54 (1999) 619
3) T. Kojima, H. Sunaga, and R. Tanaka, IAEA-CSP-18/CD
IAEA-SM-365/56, (2003) 216－ 199 －

This is a blank page.

－ 201 －This is a blank page.

－ 203 －JAEA-Review 2007-060

5-02 Operation of AVF Cyclotron
a)

a)

a)

a)

a)

a)

T. Nara , T. Agematsu , I. Ishibori , S. Kurashima , K. Yoshida , T. Yuyama ,
a)
a)
a)
a)
a)
a)
T.Ishizaka , S. Okumura , N. Miyawaki , H. Kashiwagi , Y. Yuri , W. Yokota ,
b)
b)
b)
b)
b)
b)
K. Akaiwa , To. Yoshida , S. Ishiro , Y. Arakawa , Tu. Yoshida , S. Kanou ,b)b)
A. Ihara and K. Takano
a)b)Department of Advanced Radiation Technology, TARRI, JAEA. Beam Operation Service, Co., Ltd.

Operation
The AVF cyclotron was smoothly operated in fiscal 2006
and all the planned experiments were carried out without
cancellation due to troubles relating to the cyclotron. The
operation condition of the cyclotron is frequently changed
because many kinds of ion species are required for the
research in materials science and biotechnology with short
irradiation time around an hour. Therefore the number ofannual experiments reached 840. Table 1 shows thestatistics for the cyclotron operation. The total operation
time amounts to 3459.2 hours which is the longest so far.

Metal
1.8%
Xe
3.2%
Kr
2.0%
Ar
5.2%

2715.3 hr
693.0 hr50.9 hr3459.2 hr

Change of particle and/or energy
Change of beam course
Change of harmonic number

247 times
370 times
69 times

The number of experiments
Experiment canceled due to machine trouble

840
0

The percentages of operation time of the year used forexperiments, joint-use, machine tuning, and beamdevelopment are 72.8%, 5.7%, 20.0%, and 1.5%,
respectively.
A multi-cusp ion source used to produce hydrogen ions.
In the case of production of ions heavier than He, two ECR
ion sources are used alternatively. Table 2 shows the ratios
of operation time of each ion source. Figure 1 shows
popularity of major ions used for experiments. The tendencyof those statistics is similar to that of the past years.
Table 2.
Ion source

Operation times of ion sources.
Operation time
Ratio

Multi-cusp
ECR (OCTOPUS)
ECR (HYPERNANOGAN)

1027.2 hr
1826.7 hr
991.5 hr

26.7%
47.5%
25.8%

Maintenance
The number of the troubles of the year was 324, and they
were quickly repaired without cancellation of experiments.
The regular yearly overhaul was carried out for five
weeks in summer. About two hundreds of the rubber hoses
which deteriorated in a high temperature and radiation
environment for more than 15 years were renewed. The

Cocktail
14.5%

Ne
12.7%

H
28.4%

C
24.5%

He
5.8%

O
0.9%

Table 1. Statistics for cyclotron operation in fiscal 2006.
Beam service time
Machine tuning
Beam development
Total operation time

B and Si
1.0%

Fig. 1

Major ion species used in fiscal 2006.

internal seals of about four hundreds Vebeo joints whichwere used for copper pipes of the trim-coils were replaced
because cracks were found on a number of the seals.
The routine maintenance of power supplies for a week inautumn Most current power supplies were modified tomaintain good performance for the next reason. A DAC
amplifier of a current feedback control circuit in each power
supply was enclosed in a constant-temperature box heated to
50 ℃ by a thermostat-controlled oven for high current
stability. However, breakdown of some parts in the DAC
amplifier was increasing, and it was found that thistemperature hastened deterioration of the parts. Therefore,
the temperature has been changed to 25℃ which is kept bya Peltier device. The stability of intensity and position ofbeam has been improved as a result, which helps to shorten
the time of beam tuning for the microbeam formation.
Technical development
The beam acceleration tests were successfully carried out
for 14 MeV H+, 39 MeV 28Si10+ and 60MeV 11B3+, andthey are ready to be used for experiments.
The development of a multipole magnets system foruniform-irradiation has been started. It allows exactly
simultaneous beam irradiation over a wide area at highuniformity1), which is impossible by means of rasterscanning of a spot beam.
The main beam-probe of the cyclotron has been modified
to measure a beam phase width using a plastic scintillator
and a test experiment was successfully done.
Reference
1) Y. Yuri et al., Proc. 3rd Annual Meeting of Particle
Accelerator Society of Japan 31st Linear Accelerator
Meeting in Japan, (2006) 913.

－ 204 －

JAEA-Review 2007-060

5-03 Operation of the Electrostatic Accelerators
a)

a)

a)

a)

a)

a)

K. Mizuhashi , S. Uno , K. Ohkoshi , A. Chiba , K. Yamada , Y. Saitoh ,
a)
a)
a)
b)
b)
b)
Y. Ishii , T. Satoh , W. Yokota , T. Kitano , T. Takayama , T. Orimo ,
b)
b)
b)
b)
S. Kanai , A. Ohmae , M. Kouka and Y. Aokia)

Department of Advanced Radiation Technology, TARRI, JAEA,
Operation Service, Co., Ltd

1. Status of electrostatic accelerators
Three electrostatic accelerators of the TIARA
facility operated smoothly in fiscal 2006 and all theplanned experiments were carried out, except thosecanceled by users. The operating times of the tandem
accelerator, the single-ended accelerator and the ion
implanter were 1959.6, 2498.6 and 1898.9 hours
respectively. These are almost same as the past years
but the number of operating day increased. The total
operating times since operation started are 24821,
29585 and 23226 hours, respectively. Figure 1 shows
the total time of each accelerator from 1991 to 2006.

Operating time (H)

35000
30000
25000
20000

TandemSingle ended
Implanter

15000
10000
5000
0

91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06

Fiscal year

Fig.1 Total operating time of each accelerator
since operation started
The number of the troubles was small comparedwith the past years. The troubles of the year arecharacterized by the failure of condensers. Many
condensers are used in the power supplies and thecomputers of the accelerator system. A lifetime of acondenser is generally about 10 years, but most of
power supplies of the TIARA facility are used over 15
years. Main troubles of condenser are as follows. The
condensers used in the computers of the tandem
accelerator control system for seven years failed and anumber of the abnormal condensers were found in
three of six control computers. The single-end
accelerator was stopped for two days since thecondenser of the RC oscillation circuit for the RF ion
source was shorted. All the lost beam time due tothe troubles was compensated in the year.

b)

Beam

move more lightly. This drastically reduced the dust
production by the chain rotation at high speed 1), andthe ripple of the high voltage terminal attributed to thechain vibration lowered by about 20% due to betterstability of the chain rotation. As to single-ended
accelerator, the damage of the plastic electric
insulation support for the RF-electrode frequently
occurred because of the heating by the electric
discharge occurred at the bubble parts in the support.
In order to prevent the damage, the supports made ofpolypropylene were replaced with those ofpolycarbonate after checking that they had no bubbles
by eyes through their transparency.
The cluster ions of C and Au are accelerated by thetandem accelerator, but most (more than 90%) ofclusters are broken up by the collision with the charge
exchange gas N 2. Therefore, the gas stripper system
was modified so as to measure the charge exchange
efficiency for various gas species. The results of themeasurement indicate that a gas with a larger
molecular weight gives the higher charge exchange
efficiency 2) .
3. New beam development
As to the ion implanter, the Ge ion, which wasrequested by the users of the inorganic functional
material research, was newly accelerated. It isdifficult to stably generate ions of a low melting-pointmaterial, such as Ge, with a Freeman ion source
because it easily runs from the material holder.
Therefore, the holder has been modified so that the
short of the arc circuit by the melted material and its
loss should not take place. Stable Ge ion beam was
successfully generated as a result and about 5μA wasaccelerated.
References
1) K.Mizuhashi,et al.,JAEA Takasaki Annual Report2005(2006)197
2) K.Ohkoshi,et al.,JAEA Takasaki Annual Report2005(2006)192

2. Improvement for the accelerators
The sliding mechanism for one of a couple of thechain motors of the tandem accelerator, which give
constant tension to the pellet chain, was modified to－ 205 －

JAEA-Review 2007-060

5-04 Radiation Control in TIARA
T. Seki, T. Tsujimoto and K. Ida
Department of Administrative Services, TARRI, JAEA
1 Individual monitoring(1) Individual monitoring for the radiation workers
Table 1 shows a distribution of effective dose of theradiation workers in FY 2006. The effective dose values ofalmost all radiation workers were below the detection limit(0.1 mSv).
The maximum dose was 0.6 mSv/y due to the overhaul of
the TIARA AVF cyclotron.

Table 3. Monitoring results of released radioactive gases
and dust in FY 2006.
NuclideMaximum concentration
41

Ar

11

1st
2nd
3rd
4th
quarter quarter quarter quarter

Items
Distribution rangeof effective doseC

HE ＜ 0.1

512

0.1 ≦ HE ≦ 1.00

1.0 ＜ HE ≦ 5.0

0

HE:Effective dose *1 5.0 ＜ HE ≦ 15.0
(mSv)
15.0 ＜ HE
Number of persons under radiation
control (A)
Number of persons
Exposure(B)above 1mSv （B）/（A）×100（%）
Mass effective dose (Person・mSv)

553
8
0

542
2

567

(Bq/cm3)

Activity (Bq)

N

Total

2nd
quarter<1.4×101.2×10

8

0

0

0

0

0

0

0

0

0

0

0

512

561

544

567

640

0

0

0

0

0

0

0

0

0

0

0.0

2.2

0.3

0.0

2.5

Mean dose (mSv)

0.00

0.00

0.00

0.00

0.00

Maximum dose (mSv)

0

0.6

0.2

0

0.6

*1 Not detected according to internal exposure.

(2) Individual monitoring for the visitors and others
Table 2 shows number of persons who temporally entered
the radiation controlled areas. The effective dose of all
persons was less than 0.1 mSv.

<1.5×1088

3.8×10

1.7×10

-4

18

F

77

Kr

133

Xe

<1.4×10<1.5×10<1.5×10<1.5×10 -4

8

8

8

1.0×10 9-4<1.5×10 -4

7

2.3×10 7-4<1.5×10 -4

7

4.1×10 7

1.8×10

1.5×1065

Zn

2.3×10<1.5×10
4.1×10-4<1.5×10-4<1.5×10-4<1.5×10 -4

6

7

7

9.3×10 7<1.4×108.6×10

Activity (Bq)

Activity (Bq)

7.1×10

1.3×10<5.1×100-10<6.3×100

1.3×10-4<1.5×10-4<1.5×10 -4

7

6

1.6×10 7-10<6.7×10 -10<1.4×10(Bq/cm3)(Bq/cm3)

1.2×10<1.5×10

Activity (Bq)

Maximum concentration

1.5×10 9

8.6×108(Bq/cm3)

Activity (Bq)

1.8×10 -4

8-4

Activity (Bq)

(Bq/cm3)

1.8×10

Total
-4

-4

Maximum concentration

9

0

-4

-4

Maximum concentration

631

1.4×104th
quarter-4<1.4×10
5.9×10-4

3rdquarter(Bq/cm3)

Maximum concentration

0

0

Activity (Bq)

1stquarterMaximum concentration

Number of persons in each periods

persons(Bq/cm3)

Maximum concentration

13

Table 1. Distributions of the effective dose of the radiation
workers in FY 2006.

Periods
Items-10

2.8×10<6.7×100-10<6.3×100

0

3 Monitoring for external radiation and surface
contamination
External radiation monitoring was routinely carried out
in/around the radiation controlled areas and surface
contamination monitoring was also carried out. Neither
unusual value of dose equivalent rate nor surface
contamination were detected.
Figure 1 shows a typical example of distribution of thedose equivalent rate at the radiation controlled area in thecyclotron building.

Table 2. Number of persons who temporary entered theradiation controlled areas in FY 2006.
Periods

1stquarter

2ndquarter

3rdquarter

4thquarter

Total

Number of persons

425

545

622

491

2083

2

Monitoring of radioactive gas and dust
Table 3 shows the maximum radioactive concentrations
and total activities for radioactive gases released from thestack of TIARA, during each quarter of FY 2006.
Small amount of 41Ar, 11C, 13N, 18F, 77Kr and 133Xe weredetected for some time during operation of the cyclotron or
experiment, but the pulverized substances (65Zn, etc.) were
not detected.

Fig.1. Dose equivalent rate distribution at the radiation
controlled area in the cyclotron building.
Measurement date : 27th March 2007
Measuring position : Indicated with × 1m above floor
Unit :μSv/h (the dose equivalent rate less than 0.2
μSv/h is not indicated)－ 206 －

JAEA-Review 2007-060

5-05 Radioactive Waste Management in TIARA
J. Yoshii and N. Higuchi
Department of Administrative Services, TARRI, JAEA
1. The radioactive wastes management
The radioactive wastes generated in TIARA are
managed by Utilities and Maintenance Section. The mainradioactive wastes are the solid wastes generated by the
research experiment and the maintenance of the cyclotron.
Other radioactive wastes are the liquid wastes such as
inorganic waste fluids generated from the researchexperiment and the air-conditioning machines in controlled
area. These wastes are managed according to properties.
2. Solid radioactive waste
Table 1 shows the amounts of solid wastes at various
properties and kinds generated in each quarter of FY 2006.
The main solid waste is generated by the researchexperiment and the maintenance of the cyclotron.

Table 1.

Amounts
Items
Category A*
1)Combustible2)Incombustible
Compressible
Filters
Incompressible
Ion exchange resin
Category B*

Amounts of generation in each periods (m3)
2nd
3rd
4th
1st
Total
quarterquarterquarterquarter
0.38
0.44
0.28
0.38
2.73
0.30
0.44
0.40
0.48
1.40
0.08
0
0.14
1.11
1.33
0.08
0
0.14
0.24
0.46
0
0
0
0.87
0.87
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

Table 2.

Items
Category A*
1)Inorganic2)Organic
Organic
Oil3)Sludge4)Evaporation residue
Category B*

3. Liquid radioactive waste
Table 2 shows the amounts of liquid wastes generated ineach quarter of FY 2006. Liquid waste was almost inorganic
waste water generated with chemical experiments andoperation of air conditioning units installed in each room of
the first class radiation controlled area. Larger quantity of
waste water in summer season (2nd quarter) is mainly due
to condensed water, which is treated by evaporation, andinorganic water is reused in the controlled area. Only small
amounts of concentrated liquid are generated by theevaporation.

Radioactive solid wastes generated in FY 2006.

* defined by dose at the outer surface of** 200-liter drum

Amounts

Combustible wastes are rubber gloves, paper, andclothes, etc. Incombustible wastes are metal pieces, theglasses, and contaminated parts.

Number of
package
/drum
9**
0
3**
0
0
0
0

container : (A) ＜ 2 mSv/h ≦ (B)Radioactive liquid waste generated in FY 2006.

Amounts of generation in each periods (m3)
1st
2nd
3rd
4th
Total
quarterquarterquarterquarter
10.42
16.90
6.08
8.60
42.00
10.42
16.90
6.08
8.40
41.80
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.10
0.10
0
0
0
0.10
0.10
0
0
0
0
0

* defined by concentrations in Bq/cm3(β,γ) : (A) ＜ 3.7×10 ≦ (B) ＜ 3.7×104－ 207 －

Number of
package/drum
treatment
0
0
0
1
1
0

JAEA-Review 2007-060

5-06 Utilization of the Electron Accelerator andGamma-ray Irradiation Facilities
T. Kojima a), H. Kaneko a), N. Haneda a), H. Hanaya a), R. Yamagata a), H. Seito a), T. Kanazawa a) ,S. Koyama b), T. Yamaguchi b), I. Kawashima b), N. Yagi b) and M. Takagi b)a)

Department of Advanced Radiation Technology, TARRI, JAEA ,b)Radiation Application Development Association, RADA

1. Present status of the utilization of electron
accelerator and gamma-ray irradiation facilities
An electron accelerator and three gamma ray
irradiation facilities were operated for various
research subjects as operation plan in FY 2006
without serious trouble. Distribution of research
fields and number of experiment subjects are shownin Fig.1 and Fig.2, respectively. The number of
research subjects for the electron accelerator, thecobalt first facility, the cobalt second facility, andthe food irradiation facility, is 544, 159, 622, and357, respectively. Those for gamma-ray irradiation
facilities in FY 2006 are lower than those in FY
2005, while it shows the increase of longer-time
irradiation for radiation-resistance tests ofmaterials and apparatus used in nuclear power
plants or space.

Gamma-ray Irradiation Facilities

Electron Accelerator
Basictechnology,
9.2%

14.0%

Material
processing,
60.8%

Environm
ent, 3.9%
Material
for space,
2.5%

Basic
technology,
5.7%

Joint use,

Joint use;
16.8%

Material
processing;
33.7%

Resource& Biotechnology;
21.6%

Heatresist;
0.4%

Environm
ent; 4.1%

Heatresist,
9.6%

Nuclearfacilities;
14.1%

Material
for space;
3.5%

Fig.1 Distribution of research fields (FY 2006).

Electron Accelerator

Gamma-Ray Irradiation Facilities
Joint use

Resource & Biotechnology

700

Basic technology

600
500

Environment

400

Nuclear facilities

300

Material for space200

Heat-resist

100

Material processing

0
2002

2003

2004

2005

1600
Number of research subjects

Number of research subjects

Joint use

800

Resource & Biotechnology

1400

Basic technology

1200

Environment

1000
800

Nuclear facilities

600

Material for space400

Heat-resist

200

Material processing

0
2002

2006

2003

2004

2005

Fig.2 Number of research subjects (FY 2002-2006).

－ 208 －

2006

JAEA-Review 2007-060

5-07 Operation of the Electron Accelerators andGamma-ray Irradiation Facilities
a)

a)

a)

a)

a)

a)

H. Kaneko , H. Hanaya , N. Haneda , R. Yamagata , H. Seito , T. Kanazawa ,
a)
b)
b)
b)
b)
b)
T.Kojima , S.Koyama , T. Yamaguchi , I. Kawashima , N. Yagi and M. Takagib)

Department of Advanced Radiation Technology, TARRI, JAEA , Radiation
Application Development Association , RADA

Operation time (h)1. Operation
1.1 Electron accelerator
The electron accelerator was on service without serious
trouble in 9:00～17:30 on Monday and Friday, and in
8:30～23:00on Tuesday to Thursday, to satisfy demand ofoperation time from users.
The annual operation time for the electron accelerator,
as shown in Fig.1, is 597.4 h (517 h for vertical beams,
80.4 h for horizontal beams）. That for the accelerator
No.2 operated until 2004 is also shown in Fig.1. Total
operation time of the accelerator No.1 in FY2006 is about
30 % lower than that in FY2005, but the number of
research subject in FY2006 is the same as that in FY2005
indicating the increase of short time irradiation
experiments. The accelerator served mainly forgraft-polymerization for new material development,
radiation effect study on semiconductors, and various
experiments of visiting users.
1000
900
800
700
600
500
400
300
200
100
0

No.1 accelerator

2002

2003

2004

No.2 accelerator

2005

No.1 facility

No.2 facility

Food facility

25000

Operation time (h)

a)

20000
15000
10000
5000
0
2002

2003

2004

2005

2006

Fig.2 Yearly operation time.

Fig.2 Sift of annual operation of
gamma-ray irradiation facilitiestime

60

Co

for development of new functional materials and otherresearch subjects of visiting users, involving irradiation
room No.6 operated as hourly scheduled. The foodirradiation facility served mainly for development ofdetection method for irradiated foods and radiation
resistance testing at lower dose rates.
2. Maintenance
2.1 Electron accelerator
The operation of the accelerator was interrupted for 10
days in October, 2006 and 5 days in March 2007 becauseof periodical maintenance check of accelerator body andincidental equipment, e.g. conveyor and doors ofirradiation room and repair of current measurement
system at the horizontal beam line.

2006

Fig.1 Sift ofFig.1
annualtime of electron
Yearlyoperation
operation time.
accelerators
1.2 Gamma-ray irradiation facilities
The Co-60 gamma-ray irradiation facilities consist of
three buildings (8 rooms) and cover a wide dose-rate
range from 0.04 Gy/h to 20 kGy/h with eight irradiation
cells. The annual operation time for the cobalt first,
second irradiation facilities and food irradiation facility is
20,844 h, 6,335 h and 3,150 h, respectively, as shown in
Fig.2.
The first irradiation facility served mainly forradiation-resistance testing of cables used in nuclear
power plants and various materials used in J-PARC
facility with long irradiation period. The second
irradiation facility served mainly

2.2 Gamma-ray irradiation facilities
The periodical maintenance check mainly of mechanicalsystem for radiation source transportation has been
performed every three year among three gamma-ray
irradiation facilities one by one. The periodical check mainlyof interlock system has been performed two times a year for
all the facilities.
The maintenance check of the cobalt first irradiation
facility was done in July 2006, with 18 days interruption.
The control system for the cobalt second irradiation facility
was 18 years old and therefore waiting for replacement of
the sequencer for operation.
Co-60 sources were purchased and loaded to theirradiation room No.6 in the second irradiation facility tomaintain total activities of the room. The old waste
sources of about 30 pieces were disposed through JRIA.

－ 209 －

JAEA-Review 2007-060

5-08 COMMON USE PROGRAM in Takasaki
M. Otsubo , M. Hoto and R. Suzuki
Department of Advanced Radiation Technology, TARRI, JAEA

regular&irregular

regularrefereeyesnocharge*A

irregularBirregular

Total

application

proprietary

User

OthersresultNonproprietary

Table.2 User’s affiliation of each facility

5
3
1
6

2
0
0
0

3
2
0
1

10
5
1
7

Co-60 Gamma-ray
Irradiation Facility

5

0

12

17

Electron Accelerator

8

0

6

14

Total

28

2

24

54

Facility
AVF Cyclotron

TIARA

Table.1 Classification of COMMON USE PROGRAM
exceptpurposeresearch and development
R&D
classify
prioritycommercial
general-cationcase

3. Use in 2006
There were 28 Research Proposals in 2006 at Takasaki,and 16 of all hoped to use with open result. Including theusers from priority case, we accepted 325 applications from
54 users and half of the users were new. We can find thatthe percentage of users from universities exceeds the others
except Co-60 Facility from Table.2. However we expect
there should be latent needs in the industries. Therefore weare trying to find them by the public relations asabove-mentioned and also going to start another new
system.
Figure.1 shows classification of all 325 applications. On
TIARA, Non-proprietary use represents more than 50%,
while Co-60 Facility and Electron Accelerator have a few%.
This tendency may come from the user’s affiliation.

PublicInstitute
University

1. Introduction
The facilities of JAEA is widely opened to users likefrom universities, public institutes, and the industries, etc.
COMMON USE PROGRAM, the system of facility use forthe user’s purpose on fee-charging basis, started since 2006
taking over the former system. There are 3 OPEN USE
facilities in Takasaki; Co-60 Gamma-ray Irradiation
Facilities, Electron Accelerator and TIARA. In addition tothese, some of the off-line devices can be used.
We round up the Research Proposals dividing one year
into two terms, and the execution possibility and the validityof the experimental plan are checked by the special
committee. The facility usage fee will be the total of theadmission fee, irradiation fee and additional charge. Incase of Non-proprietary research, the users must report theirradiation result to JAEA, and could be exempt from
irradiation fee. JAEA will open the reports to the public. It
is also possible for universities to apply from the facility use
program of Tokyo University. Those applications are
accepted as priority case. Table.1 shows the outline of the
program.

3MV Tandem Accelerator
3MV Single-ended Accelerator
400kV Ion ImplanterC*A= admission fee + additional charge
B= admission fee + irradiation fee + additional charge
C= admission fee + irradiation fee + depreciation

100%
90%
80%

4%
28%

34%

32%
5%

70%

2. Public relations
The information like an outline of this system, guidelines
for applicants, format download, etc can be seen on JAEA
website(http://www3.tokai-sc.jaea.go.jp/sangaku/3-facility/index.html). In addition to this, we go out for publicity andto search current needs of the outside of JAEA. In 2006, weparticipatedin
15thPolymer
Material
Forum(Osaka),Seminar for advancement of RI/radiation
use(Nagoya), Opening Symposium of Center for Flexible
Micro machining(Tokyo), and so on.

60%

15%

50%
40%
30%

65%

64%

2%
Co-60 Gamma-ray(191)

Electron Acc(72)

Non proprietary

proprietarypriority case

except R&D

51%

20%
10%
0%

ＴＩＡＲＡ
(62) *

Fig.1 Percentage of each classification* the number of application－ 210 －

－ 211 －This is a blank page.

JAEA-Review 2007-060

Appendix 1. List of Publication
A1.1 Publications in Journal
06J001 1-06

I

Hirao and H. Itoh,

F. Takano, W. Wang, H. Akinaga, H Ofuchi,“Charge Induced in 6H-SiC PN Diodes by

S. Hishiki and T. Ohshima,

Irradiation of Oxygen Ion Microbeams”“Characterization of Mn-doped 3C-SiC prepared

Materi. Sci. Forum., 527-529 (2006) 1347-1350.

by ion implantation”

06J006 1-06

J. Appl. Phys., 101 (2007) 09N510.

E

F. Schmid, S. A. Reshanov, H. B. Weber, G. Pensl,

06J002 1-06

E

M. Bockstedte, A. Mattausch, O. Pankratov, T.

G. Pensl, F. Schmid, S. A. Reshanov, H. B. Weber,Ohshima and H. Itoh,

M. Bockstedte, A. Mattausch, O. Pankratov, T.

“Deactivation of nitrogen donors in silicon

Ohshima and H. Itoh,carbide”“(Nitrogen-Vacancy)-Complex Formation in SiC:

Phys. Rev., B 74 (2006) 245212.

Experiment and Theory”

06J007 1-06

Materi. Sci. Forum., 556-557 (2007) 307-310.

I, S

S. Kuroda, S. Marcet, E. Bellet-Amalric, J. Cibert,

06J003 1-06

I,G

H. Mariette, S. Yamamoto, T. Sakai, T. Ohshima

K. K. Lee, M. Laube, T. Ohshima, H. Itoh and G.

and H. Itoh,Pensl,“Structural Analysis of (Ga,Mn)N Epilayers and“Hall Effect and Admittance Measurements of

Self-Organized Dots using MeV Ion Channeling”

n-channel 6H-SiC MOSFETs”

Phys. Stattus. solidi (a) 203 (2006) 1724.

Materi. Sci. Forum., 556-557 (2007) 791-794.

06J008 1-07
06J004 1-06

T, I

E

T. Umeda, J. Isoya, T. Ohshima, N. Morishita,

T. Ohshima, T. Satoh, M. Oikawa, S. Onoda,

H. Itoh and A. Gali,

S. Hishiki, T. Hirao, T. Kamiya, T. Yokoyama,“Identification

A. Sakamoto, R. Tanaka, I Nakano, G. Wagner,

antisite-vacancy pairs in 4H-SiC”

and H. Itoh,Phys. Rev., B 75

(2007) 245202.

Obtained for 6H-SiC n+p Diodes Irradiated with

06J009 1-07

EGold Ions”

T. Umeda, N. Morishita, T. Ohshima, H. Itoh andMateri. Sci. Forum., 556-557 (2007) 913-916.

J. Isoya,ofpositively

chargedcarbon“Degradation of Charge Collection Efficiency“Electron

06J005 1-06

paramagnetic

resonance

study

T,I

carbon antisite-vacancy pair in p-type 4H-SiC”

T. Ohshima, T. Satoh, M. Oikawa, S. Onoda, T.

Materi. Sci. Forum., 556-557 (2007) 453-456.
－ 213 －of

JAEA-Review 2007-060

06J010 1-07

T

06J015 1-09

O

J. Isoya, M. Katagiri, T. Umeda, N. T. Son,

Miyashita, T.Ohnuma, M.Iwasawa, H.Tsuchida

A. Henry, E. Janzén, T. Ohshima and H. Itoh,and M.Yoshikawa,“Shallow phosphorus donors in 3C-, 4H-, and“Generation of amorphous SiO2/SiC interface

6H-SiC”

structure by the first-principles

Materi. Sci. Forum., 527-529 (2006) 593-596.

molecular dynamics simulation”
Materi. Sci. Forum., 556-557 (2007) 521.

06J011 1-07

E ＴＧＥ

T. Umeda, N. T. Son, J. Isoya, N. Morishita,

06J016 1-09

O

T. Ohshima, H. Itoh and E. Janzén,

T.Ohnuma,

A.Miyashita,“Electron paramagnetic resonance of the HEI4/SI5

M.Yoshikawa and H.Tsuchida,

center in 4H-SiC”“Dynamical simulation of SiO2/4H-SiC(0001)

Materi. Sci. Forum., 527-529 (2006) 543-546.

interface oxidation process: from first-principles”

M.Iwasawa,

Materi. Sci. Forum., 556-557 (2007) 615.

06J012 1-07

E

N. T. Son, T. Umeda, J. Isoya, A. Gali, M.

06J017 1-10

Bockstedte,

H. Ofuchi, T. Nishiwaki, K. Takaba, K. Ogawa,B.

Magunsson,

A.

Ellison,N.

I

Morishita, T. Ohshima, H. Itoh and E. Janzén,

M. Tabuchi, Y. Takeda, A. Wakahara, A. Yoshida,“Divacancy model for P6/P7 centers in 4H- and

T. Ohshima and H. Itoh,

6H-SiC”“Fluorescence EXAFS study on local structures

Materi. Sci. Forum., 527-529 (2006) 527-530.

around Eu atoms implanted in AlxGa1-xN”
Physica B 376-377 (2006) 496-498.

06J013 1-08

E

H. Matsuura, S. Kagamihara, Y. Itoh, T. Ohshima

06J018 1-10

I

and H. Itoh,

A. Wakahara“Mechanisms of reduction in hole concentration in“IMPACT OF AlGaN ON LUMINESCENCE

Al-doped 4H-SiC by electron irradiation”

CAPABILITY OF RARE?EARTH IONS IN

Microelectron. Eng., 83 (2006) 17.

AlGaN”
Opt. Mater., Vol. 28, Issues 6-7 (2006) 731-737.

06J014 1-08

E

H. Matsuura, S. Kagamihara, Y. Itoh, T. Ohshima

06J019 1-27

and H. Itoh,T. Yamaki, Y. Kozone, A. Hiroki, M. Asano, H.

“Relationshipbetweendefects

inducedby

C, E, G

Kubota and M. Yoshida,irradiation and reduction of hole concentration in“Nano-structure controlled polymer electrolyte

Al-doped 4H-SiC”

membranes for fuel cell applications prepared by

Physica B 376-377 (2006) 342.

ion beam irradiation”
ESC Transaction, 3 (2006) 103-112.

－ 214 －

JAEA-Review 2007-060

06J020 1-27

C, E, G

06J025 2-03

E

T. Yamaki, Y. Kozone, A. Hiroki, K. Hosoi,

N. Ito, A. Mase, N. Seko, M. Tamada, E. Sakata

M. Asano, H. Kubota and M. Yoshida,

and Y. Kogi,“Proton exchange membranes for fuel cell

“Surface Treatment of Poly(tetrafluoroethylene)

applications prepared by ion track technology”

and Perfluoroethylene-propylene by Radiation

Electrochemistry, 75, No. 2 (2007) 175-178.

Grafting”
Jpn. J. Appl. Phy., 45 (12), (2006) 9244.

06J021 1-28

E, G

J. Chen, M. Asano, Y. Maekawa and M. Yoshida,

06J026 2-04

E

“Suitability of some fluoropolymers used as base

A. Iwanade, T. Nomoto, D. Umeno, .K. Saito andfilms for preparation of polymer electrolyte fuelT. Sugo,cell membranes”“Protein Binding Characteristics of AmphotericJ. Membr. Sci., 277 (2006) 249-257.

PolymerBrushes

Graftedonto

PorousHollow-Fiber Membrane”

06J022 1-28

E, G

J. Ion Exch., accepted.

J. Chen, M. Asano, T. Yamaki and M. Yoshida,“Preparation and characterization of chemically

06J027 2-06

stable polymer electrolyte membranes by

Y. Wada, M. Tamada N. Seko and H. Mitomo,

radiation-induced

copolymerization

of

four

“Emulsion

E

grafting

of

vinyl

acetatemonomers into ETFE films”

pre-irradiated poly(3-hydroxybutyrate) film”

J. Membr. Sci. 269(1-2) (2006) 194-204.

J. Appl. Polym. Sci., in press.

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J. Chen, M. Asano, T. Yamaki and M. Yoshida,

N. Seko, Y. Ueki, H. Hoshina and M. Tamada,“Chemical and radiation crosslinked polymer“Preparation of graft adsorbent having amine

electrolytegroups and its Au(III) adsorption performance”

membranes

radiation-grafted

ETFE

prepared
films

for

from
DMFC

J. Ion Exch., in press.

applications”

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J. Power Sources, 158 (2006) 69-77.

E

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06J024 1-28

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“Synthesis

of

graft

adsorbent

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N-methyl-D-glucamine for boron adsorption”

Kubota and M. Yoshida,

J. Ion. Exch., in press.

with“Preparation of ETFE-based fuel cell membranes
by UV-induced photografting and

06J030 2-09

Eelectron beam-induced crosslinking techniques”

Md. R. Awual, A. Jyo, M. Tamada and A. Katakai,

J. Membr. Sci., 283 (1-2) (2006) 373-379.

“Zirconium(IV)loadedbufucntuonal

fiber

containing both phosphonate and sulfonate as－ 215 －

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arsenate adsorbent“

06J036 3-06

C

J. Ion Exch., Vol. 18, No.4 (2007) in press.

H. Yamaguchi, T. Morishita, K. Degi,

A. Tanaka,

N. Shikazono and Y. Hase,

06J031 2-13

E

“Effect of Carbon-ion Beams Irradiation on

Y. Ueki, N. Seko, H. Hoshina and M. Tamada,

Mutation Induction in Rice”“Preparation

Plant Mutation Reports 1(1) (2006) 25-27.

Fabric-basedofPolylactic

Acid

Nonwoven

Metal

Adsorbent

byRadiation-Induced Graft Polymerization”

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“Specificity of mutations induced by carbon ionsT. M. Quynh, H. Mitomo, N. Nagasawa, Y. Wada,in budding yeast Saccharomyces cerevisiae”

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“Properties of crosslinked polylactides (PLLA &PDLA) by radiation and its biodegradability”

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Y. Sekozawa, S. Sugaya and H. Gemma.

M. Takigami, H. Amada, N. Nagasawa, T. Yagi,“Alteration of black Sigatoka (Mycosphaerella

T. Kasahara, S. Takigami and M. Tamada

fijiensis Morelet) resistance in banana by in vitro”Preparation and characterization of CMC gels”

irradiation using carbon ion-beams”

Trans. Mater. Res. Soc. Jpn., in press.

Plant Biotechnology 24 (2007) 349-353.

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E,GG

A. Kimura, M. Taguchi, Y. Ohtani, Y. Shimada,K. Satoh, H. Ohba, H. Sghaier and I. Narumi,

H. Hiratsuka and T. Kojima,“Down-regulation of radioresistance by LexA2 in“Treatment of wastewater having estrogen activity

Deinococcus radiodurans”

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Microbiology 152 (2006) 3217.

Radiat. Phys. Chem., 76 (2007) 699-706.

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T

K. Akamatsu,

Y. Yokota, S. Yamada, Y. Hase, N. Shikazono,

“A

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methodology

forcharacterizing

I. Narumi, A. Tanaka and M. Inoue,

strand-break termini and damaged bases in plasmid“Initial yields of DNA double-strand breaks andDNA exposed to ionizing radiation”

DNA fragmentation patterns depend on linear

Anal. Biochem. 362 (2007) 229.

energy transfer in tobacco BY-2 protoplasts
irradiated with helium, carbon and neon ions”

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Radiat. Res., 167 (2007) 94-101.

A. Urushibara, N. Shikazono, R. Watanabe,－ 216 －C

JAEA-Review 2007-060

K. Fujii, P. O'Neill and A. Yokoya,

the descendants of irradiated normal human“DNA damage induced by the direct effect of He

diploid fibroblasts”

ion particles”

Mutat.

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H. Matsumoto, A. Takahashi andT. Ohnishi,

N. Hamada, H. Matsumoto, T. Hara and“Nitric oxide radicals choreograph a radioadaptive

T. Y. Kobayashi,

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Cancer Res., 67 (2007) in press.

mediating ionizing radiation-induced bystander
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Y. Kobayashi and T. Ohnishi,

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“Vanguards of paradigm shift in radiation biology:

N. Hamada, T. Funayama, S. Wada, T. Sakashita,

Radiation-induced

T. Kakizaki, M. Ni and Y. Kobayashi,

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human fibroblasts and their descendents”
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N. Hamada, H. Matsumoto, T. Hara and

06J049 3-34

C

Y. Kobayashi,

N. Hamada, G. Schettino, G. Kashino, M. Vaid,“Intercellular and intracellular signaling pathways

K. Suzuki, S. Kodama, B. Vojnovic, M. Folkard,

mediating ionizing radiation-induced bystander

M. Watanabe, B.D. Michael and K.M. Prise,effects”“Histone H2AX phosphorylation in normal human

J. Radiat. Res., 48 (2007) 86.

cells irradiated with focused ultrasoft X-rays:
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Radiat. Res., 166 (2006) 31.

Z.-G. Cui, T. Kondo and H. Matsumoto,“Enhancement of apoptosis by nitric oxide

06J050 3-39

released from α-phenyl-tert-butyl nitrone under

M. Hino, S. Wada, Y. Tajika, Y. Morimura,

hyperthermic conditions”

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J. Cell. Physiol., 206 (2006) 468.

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C

ion

C, T

microbeamirradiationinduces

ultrastructural changes in isolated single fibers of

N. Hamada, T. Hara, T. Funayama, T. Sakashitaskeletal muscle”

and Y. Kobayashi,

Cell Struct. Funct., 32 (2007) 51-56.

“Energetic heavy ions accelerate differentiation in－ 217 －

JAEA-Review 2007-060

06J051 3-42Cradiation tolerance”
Int. J. Radiat. Biol., 82 (2006) 587-592.

K. Akeo, T. Funayama, A. Ogawa, N. Hamada,
Y. Akeo and Y. Kobayashi,“Effects of gamma irradiation on bcl-2 and p53

06J056 3-47

C

expression in the porcine ciliary body”

M. Watanabe, T. Sakashita, A. Fujita, T. Kikawada,

Exp. Anim., 55 (2006) 375-381.

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S. Wada, T. Funayama, Y. Kobayashi and

06J052 3-43

C

T. Okuda,

T. Kakizaki, N. Hamada, S. Wada, T. Funayama,“Estimation of radiation tolerance against highT. Sakashita, T. Hohdatsu, T. Sano, M. Natsuhori,

LET heavy ions in an anhydrobiotic insect,

Y. Kobayashi and N. Ito,

Polypedilum vanderplanki”“Distinct modes of cell death by ionizing radiation

Int. J. Radiat. Biol., 82 (2006) 835-842.

observed in two lines offeline T-lymphocytes”

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J. Radiat. Res., 47 (2006) 237-243.

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06J053 3-43

C

M. Watanabe, T. Kikawada, Y. Nakahara,

T. Kakizaki, N. Hamada, T. Funayama,

N. Hamada, S. Wada, T. Funayama, S. Higashi,

T. Sakashita, S. Wada, T. Hohdatsu, M. Natsuhori,

Y. Kobayashi, T. Okuda and M. Kuwabara,

T. Sano, Y. Kobayashi and T. Ito,

“Radiation tolerance in the tardigrade Milnesium“Killing of feline T-lymphocytes by gamma-rays

tardigradum”

and energetic carbon ions”

Int. J. Radiat. Biol., 82 (2006) 843-848.

J. Vet. Med. Sci ., 68 (2006) 1269-73.

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06J054 3-43

CC

M. Watanabe, Y. Nakahara, T. Sakashita,

T. Kakizaki, N. Hamada, T. Sakashita, S. Wada,

T. Kikawada, A. Fujita, N. Hamada,T. Hara, T. Funayama, T. Hohdatsu, M. Natsuhori,

D.D. Horikawa, S. Wada, Y. Kobayashi and

T. Sano, Y. Kobayashi and N. Ito,T. Okuda,“Vulnerability of feline T-lymphocytes to charged“Physiological changes leading to anhydrobiosis

particles”

improve

J. Vet. Med. Sci., in press.

vanderplanki larvae”

radiation

tolerancein

Polypedilum

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C

M. Watanabe, T. Sakashita, A. Fujita, T. Kikawada,

06J059 3-48

D.D. Horikawa, Y. Nakahara, S. Wada,

E. Ling, K. Shirai, R. Kanekatsu, K. Kiguchi,

T. Funayama, N. Hamada, Y. Kobayashi and

Y. Kobayashi, T. Funayama and H. Watanabe

T. Okuda,“Contribution of circulating hemocytes to the“Biological effects of anhydrobiosis in an African

regeneration of heavy ion beams (12C5+) irradiatedchironomid,

hematopoietic organs in the silkworm, Bombyx

Polypedilum

vanderplankion－ 218 －C

JAEA-Review 2007-060

mori, through the way of phagocytosis of injured“Facilitated disassembly of polyplexes composed

cells after invasion”

ofDev. Comp. Immunol., 30 (2006) 531-541.

enhances the gene transfer efficacy”

self-assembling

amphiphilic

polycations

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C

K. Fukamoto, K. Shirai, T. Sakata, T. Sakashita,

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T. Funayama, N. Hamada, S. Wada, T. Kakizaki,

A. EL-Salmawy, T. Kitagawa, I. K. Ko,

S. Shimura, Y. Kobayashi and K. Kiguchi.

A. Murakami, Y. Kimura, T.Yamaoka and“Development of the irradiation method for the

H. Iwata,

first instar silkworm larvae using locally targeted“Preparation and properties of ProNectin F-coatedheavy-ion microbeam”

biodegradable hollow fibers”

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Journal of Artificial Organs 8 (2005) 245.

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06J066 3-53

G

O

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T. Sakamoto, A. Mahara, K. Yamagata, R. Iwase,“Free radicals in irradiated wheat flour detected by

T. Yamaoka and A. Murakami,

electron spin resonance”“Evaluation of dynamic feature of Escherichia coli

Appl. Magn. Reson. 29 (2005) 315.

16S

ribosomalRNAinhomogeneous

physiological solution”

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Biophys. J. 89 (2005) 4122.

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“Poly(lactide) swelling and melting behavior in

N. Kawachi, K. Sakamoto, S. Ishii, S. Fujimaki,

supercritical carbon dioxide and post-venting

N. Suzui, N. S. Ishioka and S. Matsuhashi,

porous material”“Kinetic analysis of carbon-11-labeled carbon

Biomacromolecules 6 (2005) 2370.

dioxide for studying photosynthesis in a leaf using
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06J063 3-53

O

IEEE Trans. Nucl. Sci., 53 (2006) 2991.

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“Analytical method for estimation of kinetics of

T. Tsukamoto, H. Nakanishi, S. Kiyomiya,oligonucleotide/RNA

S. Watanabe, S. Matsuhashi, N. K. Nishizawa andhybridization

using

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“52Mn translocation in barley monitored using a
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S

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N. Kishimoto, S. Kikuchi, H. Nakanishi, S. Mori

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S. Matsuyama, H. Yamazaki, T. Kamiya, T. Sakai,

K. Koyama .,K. Arakawa, M. Saitoh, M.Oikawa and K. Sera,
18“PET and PET/CT using F-FDG in the diagnosis“Method for Determing the localization of Traceand management of cancer patients”

Elements Observed by the Micro PIXE camera”

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Int. J. PIXE., Vol.14, Nos.3&4 (2004) 83-87.

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T. Kamiya, T. Arakawa, M. Saitoh andFullerenes by Ion Implantation”

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liquid-coremicrocapsules by Y polymerization”

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“Synthesis of Endohedral 133Xe-Fullerenol by

S. Harada, S. Ehara, K. Ishii, A. Tanaka, T. Satoh,

Using Higher Fullerene”

S. Matsuyama, H. Yamazaki, Y. Komori,

Journal of Nuclear and Radiochemical Science, in

T. Kamiya, T. Arakawa, M. Saitoh, M. Oikawa.

press.

“Optimizing

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for

the

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T, I, S

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S. Jitsukawa, L. L. Snead and A. Hasegawa,“The kinetics of Fe and Ca for the development of“Effect of displacement damage up to 50 dpa on

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“Formation of Silicone Carbide Membrane by

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Radiationand M. Yoshikawa,CuringofPolycarbosilane

andPolyvinylsilane and Its Gas Separation up too“Effect

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ValenceStateson

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Gasochromic Properties in Tungsten Oxide Thin

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Radiation Curing”“Effect of Annealing Temperature of Palladium

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Oxide Films on Gasochromic Performance”
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M. Yoshikawa and T. Shikama,of preceramic polymers”“Gasochromic Coloration of Non-stoichiometric

Mater. Sci. & Eng., B, in press, (2007).

WO3-x Films”
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L. L. Snead and A. Hasegawa,K. Takano, A. Inouye, S. Yamamoto, A. Miyashita“Effect of Al and Be ions pre-implantation on

and M. Yoshikawa,formation and growth of helium bubbles in“Effect

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Gasochromic Properties in Tungsten Oxide Thin

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M. Yoshikawa,“EffectsofComposition

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Gasochromic Coloration of Tungsten Oxide Films“Yield of OH radicals in water under heavy ion

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chromium(VI) in aqueous solution containing

catalytic

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TiO2, Al2O3 or SiO2 fine particles”

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“Contribuion of aeolian dust in Japan Sea

Y. Sugo, Y. Izumi, Y. Yoshida, S. Nishijima,

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Y. Sasaki, T. Kimura, T. Sekine and H. Kudo,

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Membranes

tapes”

Embeddedwith

ObliqueCu

Nanowires for Anisotropic Infrared Absorption”

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06J098 4-23

S“Comparative study of structures and electrical

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properties

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mixturesand P, Avramov,systematic change of cobalt content”“Planar doping of crystalline fullerene with cobalt”

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H. Naramoto, Pavel V. Avramov, K. Narumi,

Mobility in Pentacene by Microwave and Optical

V. Lavrentiev and Y. Maeda,

Spectroscopy Techniques”“Tunnelmagnetoresistancein

Co

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nanoparticle/Co-C60 compound hybrid system”
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the

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J. Vacik, V. Havranek, J. Subrtz, S. Bakardjievaz,“Formation and Decay of the Triplet Excited State

H. Naramoto and K. Narumi,of Pyridine”“Synthesis and microstructure characterization of

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Ni/C60 composite material”

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Ion-Channel Biosensors”

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Planar-Type

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SO

S. Tsukuda, S. Seki, M. Sugimoto and S. Tagawa,

S. Sakai, H. Naramoto, P. V. Avramov, T. Yaita,“Customized morphologies of Self-condensed

V. Lavrentiev, K. Narumi, Y. Baba and Y. Maeda,

multi-segment polymer nanowires”－ 223 －

JAEA-Review 2007-060

Formation by High Energy Charged Particles”

J. Phys. Chem., B, 110 (2006) 19319-19322.

Surf. Coat. Technol., 201 (2007) 8486-8489.

06J109 4-25

O

S. Seki, S. Tsukuda, S. Tagawa, and M. Sugimoto

06J114 4-25

“Correlation
Nanowires

betweenand

Width

Backbone

O

Roughnessof

S. Seki and S. Tagawa,Conformationof“Optoelectronic

Properties

andNanostructure

Polymer Materials”

Formation of σ-Conjugated Polymers”

Macromolecules, 39 (2006) 7446-7450.

Polymer J., 39 (2007) 277-293.

06J110 4-25

06J115 4-25

OO

Y. Yamamoto, T. Fukushima, Y. Suna, N. Ishii,

S. Tsukuda, S. Seki, M. Sugimoto, and S. Tagawa,

A. Saeki, S. Seki, M. Taniguchi, S. Tagawa, T.

“Effect of Ion Beam Energy and Polymer Weight

Kawai and T. Aida,on the Thickness of Nanowires Produced by Ion“Photoconductive
Molecularly

CoaxialConnected

Nanotubes

Electron

Donor

of

Bombardment of Polystyrene Thin Films”

andSurf. Coat. Technol., 201 (2007）8526-8530.

Acceptor Layers”

06J116 4-25

Science, 314 (2006) 1761-1764.

O

S. Tagawa, S. Tsukuda, S. Seki, M. Sugimoto,

06J111 4-25

O

T. Sato, M. Oikawa, and T. Sakai

A. Saeki, S. Seki, Y. Koizumi and S. Tagawa,“Ion Beam Induced Nano-Space Reactions and“Dynamics of Photogenerated Charge Carrier andNanowire Formation in Polymers by High EnergyMorphology Dependence in Polythiophene Films

Sub-μm Heavy Ion Beams”

Studied by In-Situ Time-Resolved Microwave

Surf. Coat. Technol., 201 (2007）8495-8498.

Conductivity

andTransient

Absorption

Spectroscopy”

06J117 4-25

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J. Photochem. Photobiol., A, 186 (2007) 158-165.

Y. Koizumi, S. Seki, A. Saeki, and S. Tagawa,“Electronic Properties of the Charge Carriers on

06J112 4-25

O

Oligofluorene Backbone”
Radiat. Phys. Chem., 76 (2007) 1337-1341.

K. Maehashi, H. Ozaki, Y. Ohno, K. Inoue,
K. Matsumoto, S. Seki and S. Tagawa,“FormationofSingleQuantum

Dot

in

06J118 4-25

O

Single-Walled Carbon Nanotube Channel Using

S. Seki, S. Tsukuda, S. Tagawa, M. Sugimoto,

Focused-Ion-Beam Technique”

A. Watanabe, and T. Miyashita

Appl. Phys. Lett., 90 (2007) 023103.

“FormationofIsolated

Ultrafine

OpticalNanofibers by Single Particle Nanofabrication
06J113 4-25

Technique”

O

S. Seki, S. Tsukuda, M. Sugimoto and S. Tagawa,J. Photopolym. Sci. Technol., 20 (2007) 125-128.

“Cross-Linked Silicon Based Polymer Nanowire－ 224 －

JAEA-Review 2007-060

06J119 4-25

O

Structure and Photoelectrochemical Properties ofY. Koizumi, S. Seki, K. Okamoto, A. Saeki, andPorphyrin-Fullerene

S. Seki,Electrophoretically Deposited on Nanostructured“Radiation

InducedPolymerizationof

One-Step
Functional

One-pod
ConjugatedComposite

Clusters

SnO2 Electrodes”
Chem. Eur. J., in press.

Molecules”
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06J124 4-26

T

Y. Horino, A. Chayahara, Y. Mokuno, H. Yamada

06J120 4-25

O

and N. Fujimori,Y. Yamamoto, T. Fukushima, A. Saeki, S. Seki,“High-rate

S. Tagawa, N. Ishii, and T. Aida,

microwave plasma chemical vapor deposition with

“MolecularEngineeringofCoaxialgrowthoflargediamondsbynewly designed substrate holders”

Donor-Acceptor Heterojunction by Coassembly of

New Diamond and Frontier Carbon Technology 16

Two Different Hexabenzocoronenes: Graphitic(2006) 63.

Nanotubes

withEnhanced

Photoconducting

Properties”

06J125 4-26

T

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Y. Mokuno, A. Chayahara, Y. Soda, H. Yamada,Y. Horino and N. Fujimori,

06J121 4-25

O

“High rate homoepitaxial growth of diamond by

K. Yamaguchi, T. Inoue, M. Fujii, M. Haraguchi,

microwave plasma CVD with nitrogen addition”

T. Okamoto, M. Fukui, S. Seki, and S. Tagawa,Diam. Relat. Mater., 15 (2006) 455.

“Electric Field Enhancement of Nano Gap ofSilver Prisms”

06J126 4-30

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Chin. Phys. Lett., 24 (2007) 2934-2937.

Y. Chimi, N. Ishikawa, A. Iwase and F. Ono,
“Modification of magnetic properties in Fe-Ni

06J122 4-25

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alloy thin films induced by energetic ion

A. Sharma, M. Katiyar, Deepak, S. Seki, andirradiation”

S. Tagawa,Nucl. Instrum. Methods., B 257 (2007) 388.

“Polysilane Based Organic Light Emitting Diodes:
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06J123 4-25

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H. Naramoto, K. Narumi and M. Sasase,

H. Imahori, M. Ueda, S. Kang, H. Hayashi,“Core-level

S. Hayashi, H. Kaji, S. Seki, A. Saeki, S. Tagawa,

spectra of Au clusters embedded in carbon”

T. Umeyama, Y. Matano, K. Yoshida, S. Isoda,

J. Appl. Phys., 100 (2006) 084325.

M. Shiro, N. V. Tkachenko, and H. Lemmetyinen,“Effects of Porphyrin Substituents on Film
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andvalence-band

photoemission

JAEA-Review 2007-060

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diffraction”

K. Takahiro, K. Kawatsura, S. Nagata, B. Tsuchiya,e-J. Surf. Sci. Nanotech., 4 (2006) 435.

S. Yamamoto, H. Naramoto“Improvement in Crystal Quality of Epitaxial Ag

06J134 4-34

I

and Cu Films Induced by Self-ion Irradiation”

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Surf. Coat. Technol., 201 (2007) 8273.

“Characterization of ion beam-induced SiC-OI
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M. Hashimoto, Y. Fukaya, A. Kawasuso andA. Ichimiya,“Surface structure of In/Si(111) studied by

06J135 4-35

Sreflection high-energy positron diffraction”

H.Shibata, Y.Kohno, K.Shibata, T.Sato, M.Oikawa,

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Nucl. Instrum. Phys. Res., B 260“Reflection high-energy positron diffraction study

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Nagamine,surface“The changes of heavy metal and metallothioneinbyreflection

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06J137 4-40

“Structural analysis of Ge(111)-3×3-Sn surface at

K.Ishii, H.Yamazaki, S.Matsuyama, W. Galster,

low temperature by reflection high-energy positron

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diffraction”“Contribution of Atomic Bremsstrahlung in PIXE

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Y. Watanabe, T. Yamaguchi, G. Momose,Y. Barbotteau, A. Suzuki, T. Yamaguchi,

T. Amartaivan, A. Suzuki, Y. Kikuchi and

G. Momose and H. Imaseki.

W.Galster.

“MICROBEAM“Micron-CT using PIXE with Micro-beams”

UNIVERSITY FOR BIOLOGICAL STUDIES”

Int. J. PIXE.,

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D. Satoh, T. Sato, A. Endo, Y. Yamaguchi,

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M. Takada and K. Ishibashi.

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“Measurement of response functions of liquid“Development of an image reconstruction methodorganic scintillator for neutrons up to 800 MeV”

for Micron-CT using PIXE”

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“DARWIN: Dose monitoring system applicable to

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various radiations with wide energy ranges”

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Radiat. Prot. Dosim., in press.

A.Ishizaki, R.Oyama, Y.Kawamura, A.Suzuki,
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06J145 4-46

“Microbeam analysis of single aerosol particles at

D. Satoh, T. Sato, A. Endo, N. Matsufuji,

Tohoku University”

M. Takada and S. Sato.

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S. Onoda, T. Wakasa, J. S. Laird, T. Hirao,“Identification of Qxidation States of Trace-Level

T. Kamiya, H. Itoh, A. Kinoshita, R. Tanaka,

Arsenic in Environmental Water Samples Using

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PIXE”“Characterization of charge generated in siliconInt. J. PIXE.,

Vol.15, Nos.3&4 (2005) 241-248.

carbiden+p

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Industrialization. Floriculture”

M. Oikawa, T. Satoh, T. Sakai, N. Miyawaki,

Oranamental and Plant Biotechnology Vol.I,

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pp619-628, Global Science Books (2006).

M. Fukuda, W. Yokota and T. Kamiya,“Focusing high-energy heavy ion microbeam

06J1523-23

system at the JAEA AVF cyclotron”

W. O. Reyes-Borja, I. Sotomayor, I. Garzón,

Nucl. Instrum. Methods., B 260 (2007) 85-90.

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H. Gemma

S. Kurashima, N. Miyawaki, S. Okumura,“Mutation induction by gamma-rays and carbon

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ion beam irradiation in banana (Musa spp.): a

T. Satoh, T. Nara, T. Agematsu, I. Ishibori,study with an emphasis on the response to black”

W. Yokota and Y. Nakamura,

Sigatoka disease. In M Miranda, A Lebeda (eds).

“Improvement in beam quality of the JAEA AVF

Disease Resistance – Methods for mass screening

cyclotron for focusing heavy-ion beams withof banana and other crops (book chapter 2007, inenergies of hundreds of MeV”

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N. Uchiya, T. Harada, M. Murai, H. Nishikawa,
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06J150 4-57

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T. Kojima, H. Sunaga, N. Haneda, I. Kawashima
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gamma-ray

dosimetry at JAERI involving a two-way doseintercomparison study with NPL in the dose range
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A1.2 Publication in Proceedings
06C001 1-01

I, C, T, E

and T.Hirao

C. Morioka, M. Imaizumi, T. Ohshima, H. Itoh and“Bulk Damage Caused by Single Protons in

K. KibeSDRAMs”“Study on Optimum Structure of AlInGaP Top

The IEEE Nuclear and Space Radiation Effects

Cell for Triple-Junction Space Solar Cell”

Conference (NSREC 2003).

Proc. of 4th World Conf. on Photovoltaic Energy
Conversion, May 2006 (Waikoloa), pp.1846-1849.

06C006 1-02

C

S. Kuboyama, H.Shindo S. Matsuda. and T.Hirao.

06C002 1-02

C“Consistency of Bulk Damage Factor and NIEL

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for Electrons, Protons, and Heavy Ions in Si

Iide, T. Yokose, Y. Tsuchiya, T. Arimitsu, H. Asai,

CCDs”

H. Shindou, S. Kuboyama and S. Matsuda

The IEEE Nuclear and Space Radiation Effects“Hardness-by-Design Approach for 0.15 μ m

Conference (NSREC 2002).

FullyDepleted CMOS/SOI Digital Logic Devices
with Enhanced SEU/SET Immunity”

06C007 1-04

C, T

The IEEE Nuclear and Space Radiation Effects

高橋芳浩、芝田利彦、大西一功、平尾敏雄、

Conference (NSREC 2005).

小野田忍、神谷富裕“MOS 構造における重イオン照射誘起電流”

06C003 1-02

C

電子情報通信学会論文誌, J89-C, 3 (2006) 104.

H. Shindou, S. Kuboyama, T. Hirao and S.
Matsuda

06C008 1-09

O

“Local and pseudo SELs observed in digital

Miyashita,

LSIsand their implication to SEL test method”

T.Kano, M.Yoshikawa and N.Soneda,

The IEEE Nuclear and Space Radiation Effects“Generation of Amorphous SiO2/SiC Interface andConference (NSREC 2005).

Dynamical Simulation of

T.Ohnuma,

M.Iwasawa,

T.Sakai,Interface Oxidation Process of SiC Device”

06C004 1-02

C

Annual Report of the Earth Simulator Center
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N. Ikeda, S. Kuboyama, S. Matsuda and T. Handa“AnalysisofProton-Induced

AngularDependenceofMultiple-Bit

Upsetsain

06C009 1-10

I

Synchronous SRAM”

A. Wakahara(Invited)

The IEEE Nuclear and Space Radiation Effects“Monolithic Optoelectronic Integrated Circuits”

Conference (NSREC 2005).

4th

International

Workshopon

Nanoscale

Semiconductor Devices (April 5-6, 2007, Jeju,

06C005 1-02

C

Korea) pp.221-234

H. Shindou, S. Kuboyama, N. Ikeda, S. Matsuda.
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I

to be published.

A. Wakahara, K. Takemoto, F. Oikawa and H.

06C014 2-04

Okada
“Energytransfer

processin

AlGaN:TbbyE

A. Iwanade, D. Umeno, K. Saito and T. Sugotime-resolved photoluminescence analysis”“Protein Binding to Amphoteric Polymer Brushes

IUMRS-ICA-2006 (Sept.

Grafted onto Porous Hollow-Fiber Membrane

10-14, 2006, Jeju,

Korea) 3-O-6, Abstract book p.30

submitted to Biotechnol”
Prog. submitted to Biotechnol. Prog.

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G

A. Idesaki, N. Koizumi, M. Sugimoto, N.

06C015 2-21

E

Morishita, T. Ohshima, and K. Okuno

島田明彦、田久保剛、箱田照幸、岩崎達行、“Gas Evolution from Insulating Materials for

木下忍、小嶋拓治

Superconducting Coil of ITER by Gamma Ray“ホルムアルデヒド殺菌ガスの電子ビーム処

Irradiation at Liquid Nitrogen Temperature”

理”

Proceedings of Cryogenic Engineering Conference

第 43 回& International Cryogenic Materials Conference

要旨集

アイソトープ・放射線研究発表会

p.119

2007, 16-20 July 2007, U.S.A. (To be published in

06C016 2-22

Advances in Cryogenic Engineering in 2008

G

広田耕一、趙常礼、小嶋拓治、星正敏

06C012 1-19T

“有機溶媒中ダイオキシン類の放射線分解―

K. Kondo, Y. Miwa, N. Okubo, Y. Kaji, T.

ダイオキシン類分析廃液処理法の開発―”

Tsukada.

環境と測定技術

Vol33

behavior of ion irradiated type 316L stainless

06C017 3-05

Csteel”

飯塚正英、木村康夫、長谷純宏、田中淳

Proceedings of 13th International Conference on“イオンビーム照射によるオステオスペルマム

Environmental

突然変異体の誘発”

No8

23-28

“The effects of residual stress on corrosion

DegradationofMaterials

in

Nuclear Power Systems - Water Reactors, 2007, to

園芸学研究 6 別１．470（2006）．

be published.

06C018 3-07
06C013 1-19

TC

遠嶋太志、白尾吏、上野敬一郎、大江正和、

Y. Kaji, Y. Miwa, N. Okubo, K. Kondo, T.

安庭誠、長谷純宏、田中淳

Igarashi and T. Tsukada.

“サトウキビの有用変異体作出に適するイオン“New concept of damage evaluation method for

ビーム線量”

core internal materials considering radiation

九州農業研究発表会

induced stress relaxation”

2006 年

Proceedings of Second International Symposium
on Nuclear Power Plant Life Management, 2007,－ 230 －

8月

P41

専門部会発表要旨集

JAEA-Review 2007-060

06C019 3-10

06C023 3-40

C

Y.Kawashima,Y.Hase,Y.Yokota,A.Tanaka,“EffectofIrradiation

germination,mycerial

growth

on
and

fruit

C

Y. Suzuki, K. Shirai, T. Mizui, N. Hamada, S.
spore

Noda, T. Funayama, Y. Yoshida, Y. Kobayashi, T.

body

Shirao, T. Nakano

formation of mushrooms”“Relative

Biological

Effectiveness

Value

of

Bulletin of the Gunma Prefectural Forestry

Carbon Ion Beam To X-ray on Immature

Experiment Station,12,13-20(2007).

Hippocampal Neurons in vitro”
Proceedings of the 48th Annual ASTRO Meeting,

06C020 3-25

C

Vol. 66, p. 591 (2006)

杉浦俊浩、柿薗俊英、西尾尚道“単細胞緑藻 Haematococcus pluvialis の従属栄

06C024 3-40

C養培養におけるアスタキサンチン生成の検討”

Y. Yoshida, Y. Suzuki, A. Takeuchi, N. Hamada,

第 59 回日本生物工学会大会要旨集 iD10-3, p60

K. Shirai, T. Funayama, T. Sakashita, Y.

(2006).

Kobayashi, S. Ozawa and T. Nakano“Effects of X-ray and Carbon Ion Beam on the

06C021 3-33

C

Postnatal

CerebelluminOrganotypic

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H. Matsumoto and T. Ohnishi.

Cultures”“Radiation-induced advantageous bystander effect

Proceedings of the 48th Annual ASTRO Meeting,and adaptive response through NO radical

Vol. 66, p. 250 (2006)

generations”
Proc. of Int. Symposium on Low-dose radiation

06C025 3-40

exposure and bio-defense system. Ed. S. Tanaka, K.

鈴木義行、白井克幸、水井利幸、浜田信行、

Fujikawa,

野田真永、舟山知夫、吉田由香里、小林泰彦、Y.

Oghiso.

(Sept.

28-30,

2005,

Rokkasho, Japan) pp23-26 (2006).

C

白尾智明、中野隆史“培養ラット未熟神経細胞における、アポトー

06C022 3-34

C

シスを指標とした炭素線の生物学的効果比”

N. Hamada, M. Ni, T. Funayama, T. Sakashita, T.

Proceedings of the 19th Annual Meeting of

Kakizaki, S. Wada, Y. Yokota and Y. Kobayashi.

JASTRO, Vol. 18, p. 186 (2006).

“Bystander killing in normal human fibroblasts byheavy-ion microbeams”

06C026 3-46

Extended Abstracts of the 7th International

森ちひろ、東谷篤志

Workshop:“線虫の放射線応答：重イオンマイクロビーム

Microbeam

Probesof

CellularC

Radiation Response (Mar 15-17, 2006, Columbiaを用いた研究結果を中心に”

Univ., NY, USA)

放射線生物研究 41(4), 399-408 (2006)”

Radiat. Res. 166, 684-685, 2006.

06C027 3-46

C東谷篤志
“放射線照射に対する生物応答：モデル生物 C－ 231 －

JAEA-Review 2007-060

エレガンスを用いたイオンマイクロビームの(2005).

照射研究”
111,

放射線と産業

06C032 3-54

(2006) 13-18

C

N. Kawachi, S. Fujimaki, S. Ishii, N. Suzui, N. S.

06C028 3-53

O

Ishioka, and S. Matsuhashi.

T. Hashimoto, A. Kobori, A. Murakami and T.

“A new method for parametric imaging of

Yamaoka.

photosynthesis with C-11 carbon dioxide and“The destabilization of polyplexes facilitates

positron emitting tracer imaging system (PETIS)”

intranuclear transcription dfficiency”

Proceedings

Nucleic Acids Symposium Series, 49, 365-366

Nuclear Data for Science and Technology, 2006

(2005).

IEEE Nuclear Science Symposium ConferenceofInternational

Conferenceon

Record, 3 (2006) 1519.

06C029 3-53

O

T. Sakamoto, A. Mahara, A. Kobori, T. Yamaoka,

06C033 3-58

A. Murakami.

本田修三、関本均、加藤翔太、落合由記子、“Luminescenceanisotropy-based

detection

Cof山口良恵、米山香織、米山弘一、竹内安智、

nucleic acids and proteins using long-lifetime

河地有木、藤巻秀、鈴井伸郎、石井里美、

Ru(II) complex as a luminescent label”

石岡典子、松橋信平

Nucleic Acids Symposium Series, 49, 203-204“ホスト植物が同化した炭素・窒素の根寄生植(2005).

物への分配様式のＰＥＴＩＳ法によるイメー
ジング”

06C030 3-53

O

2006 年度日本土壌肥料学会関東支部大会講演

M. Higuchi, A. Yamayoshi, A. Kobori, T.

要旨集、ｐ15．2006 年 11 月（宇都宮）

Yamaoka, A. Murakami.
“Synthesis

andantisense

properties

ofphoto-reactive

oligonucleotides

contining

06C034 3-58

C

H.Sekimoto and S.Honda

2’-O-psoralen-conjugated adenosine”“Ealuation of Effect of Root Parasite on Carbon

Nucleic Acids Symposium Series, 49, 331-332

and Nitrogen Translocation and Distribution in the(2005).

Host Plant by Positron Emitting Tracer Imaging
System (PETIS) ”

06C031 3-53

O

Proceedings

of

the

Bi-national

Japan-Israel

R. Iwase, U. Fukui, A. Kobori, T. Yamaoka, A.

Workshop on Aspects of Parasitic Weeds: biology

Murakami.

and Control.Agricultural Research Organization“Synthesis

ofantisense

oligonucleotides

the Volcani Center, March 2007 (Israel)containing a photocleavable protecting group on a
guanine base and theier photoinduced duplex

06C035 3-62

formation”

Y. Iida, H. Hanaoka, T. Katabuchi, S. Watanabe,

Nucleic Acids Symposium Series, 49, 151-152

S. N. Ishioka, S. Matsuhashi, N. Oriuchi,－ 232 －C

JAEA-Review 2007-060

INNERVISION 17/7 (2004) 27-28.

T. Higuchi, M. Miyakubo and K. Endo
“Utility of 64Cu for immuno-PET; in vivo
measurementofradiation

dose

for

06C040 3-68

Sradioimmunotherapy”

S. Harada, S. Ehara, K. Ishii, A. Tanaka, T. Satoh,Proc. of The Fifth Annual Meeting of the Society

S. Matsuyama, H. Yamazaki, Y. Komori, T.

for Molecular Imaging, The Big Island of Hawaii,

Kamiya, T. Arakawa, M. Saitoh, M. Oikawa, andUSA, 5, 361 (2006).

K. sera.
“Innovation of the Target preparation of the micro

06C036 3-62

C

PIXE Camera for the floating cells”

Y. Iida, H. Hanaoka, T. Katabuchi, S. Watanabe,

Proceeding of the 10th International Conference on

S. N. Ishioka, S. Matsuhashi, N. Oriuchi,

Particle-Induced X-ray Emission and its Analytical

T. Higuchi, M. Miyakubo, K. Endo

Applications (CDR publication)“Application of PET imaging with [Cu-64] forquantitative evaluation of radioimmunotherapy”

06C041 3-68

S

Proc. of 9th Congress of the World Federation of

S. Harada, S. Ehara, K. Ishii, A. Tanaka, T. Satoh,

Nuclear Medicine & Biology, Seoul, Korea, 5,

S. Matsuyama, H. Yamazaki, Y. Komori, T.

supple1, S189 (2006).

Kamiya, T. Arakawa, M. Saitoh, M. Oikawa and K.
sera.

06C037 3-66

S

“The alteration of the cis-platinum (Platinum

櫻井英幸、岡本雅彦、新雅子、竹内あい子、

analogues for cancer therapy) by the low dose

長谷川正俊、佐藤隆博、及川将一、神谷富裕、

irradiation

荒川和夫、中野隆史

preliminary study”“大気マイクロ PIXE を用いたヒト肺癌細胞内Proceeding of the 1oth International Conference on

シスプラチンの可視化，定量化の試み”

Particle-Induced X-ray Emission and its Analytical

第 9 回癌治療増感研究シンポジウム p30（2007）

Applications (CDR publication)

06C038 3-68

06C042 4-08

S

studiedinhumanleukemia,AI

S. Harada, K. Ishii and T. Kamiya.

H.Iwata, Y.Tokuda, M.Takagi and T.Imura,“Kinetics of cis-platinum after radiation, and“Effect of Boron Co-implantation on Hydrogentargeting of cis-platinum, directed by radiation”

induced Exfoliation”

INNERVISION (2006) 61.

Proceedings of 16th International Microscopy
Congress, Vol.3, pp.1352

06C039 3-68

(2006.9)S

S. Harada, K. Ishii and S. Obara.

06C043 4-17

“Determination of radiation Induced apoptosis by

S. Nakagawa, M. Taguchi and T. Kojima

the kinetics of the trace-elements, and predicting“LET effect on radiation of hydroxymaleimide in

the antitumor effect and prognosis of radiation

2-propanol”

therapy”

Proceeding of 49th Annual Meeting of Japanese－ 233 －C

JAEA-Review 2007-060

06C050 4-41

Society of Radiation Chemistry, 61-62 (2006).

T,I,S

阿達正浩、斎藤勇一、千葉敦也、鳴海一雅、

06C044 4-19

E, G

金子敏明

R. Nagaishi, N. Aoyagi, R. Yamada, Y. Hatano“炭素薄膜中での高エネルギー炭素クラスター

and Z. Yoshida,

イオンの荷電変換断面積の評価”“Radiation-induced reduction of metal ions in

第 54 回 応用物理学関係連合講演会 予稿集

aqueous solution systems and its application”

第 I 分冊

p.150 (2007)

Conference abstract book of the 1st asia-pacific

06C051 4-41

symposium on radiation chemistry, 83 (2006).

T,I,S

齋藤勇一、千葉敦也、 阿達正浩、鳴海一雅

06C045 4-19

E, G

“クラスターイオンのタンデム加速器透過率のY. Sugo, Y. Sasaki, T. Kimura and T. Sekine,

測定”“Radiolysis studies of amidic extractants for

春季第 54 回応用物理学関係連合講演会

partitioning of HLW”

集 第 I 分冊

p.150 (2007)

06C052 4-41

T,I,S

予稿

Proceedings of 15th International Conference on
Nuclear Engineering (ICONE-15), 10573 (2007).

斎藤勇一、千葉敦也、阿達正浩、鳴海一雅

06C046 4-25

O

“薄膜を通過させた MeV クラスターイオン構

関修平

成原子の電荷のクラスター形状依存性”“量子ビームと高分子材料の創る世界”

第７回「イオンビームによる表面・界面解析」

Optronics, 25 (2006) 166-167.

特別研究会１２月９日岡山理科大学

06C047 4-25

06C053 4-45

T,I,S

C

杉本雅樹、吉川正人、関修平、田川精一

岩元洋介、松田規宏、坂本幸夫、落合謙太郎、“イオンビームによるセラミックナノファイ

中根佳弘、中島宏、柴田徳思

バーの合成”“10MeV 陽子入射によるベリリウムからの中

Material Stage, 7 (2007) 63-67.

性子成二重微分断面積”
原子力学会｢2007 年春の年会｣、E09（2007）

06C048 4-25

T,I,S

関修平、佃諭志、田川精一

06C054 4-46C

“高分子材料の単一粒子ナノ加工と構造制御”

佐藤達彦、佐藤大樹、遠藤章

放射線化学, 83 (2007) 10-20.

“高エネルギー中性子対応マルチ放射線モニタ
DARWIN の開発”

06C049 4-41

T,I,S

放射線, 32, (2006) 233-238.

斎藤勇一、千葉敦也、鳴海一雅、阿達正浩“TIARA におけるクラスター加速の現状”

06C055 4-46

第１９回タンデム加速器とその周辺技術の研D. Satoh, T. Sato, N. Shigyo and K. Ishibashi.

究会報告集

p.13 (2006)

C“SCINFUL-QMD; Monte Carlo based computer－ 234 －

JAEA-Review 2007-060

code to calculate response function and detection(2006) p.907.

efficiency of a liquid organic scintillator forneutron energies up to 3 GeV”

06C059 4-54

S, T

JAEA-Data/Code 2006-023 (2006).

N. Uchiya, T. Harada, M. Murai, H. Nishikawa, J.
Haga, T. Satoh, Y. Ishii and T. Kamiya,

06C056 4-50

C

“Micro-machining of resists on silicon by proton

S. Okumura, S. Kurashima, N. Miyawaki, H.

beam writing”

Kashiwagi, K. Yoshida, I. Ishibori, Y. Yuri, T.

Proceedings of 10th International Conference on

Nara and T. Agematsu,

Nuclear Microprobe Technology and Applications,“Measurement of the beam energy spread at the

July 2006 (Singapore), p.189.

JAEA AVF cyclotron”
Proceedings of the 3rd Annual Meeting of Particle

06C060 4-54

S, T

Accelerator Society of Japan and the 31th Linear

打矢直之、古田祐介、西川宏之、芳賀潤二、Accelerator Meeting in Japan, Sendai, Japan

佐藤隆博、石井保行、神谷富裕(2006).p.919.

“集束プロトンビーム描画による厚膜レジストの微細加工”

06C057 4-50

C

秋季第 67 回応用物理学会、p.649、2006 年 8

Y. Yuri, N. Miyawaki, T. Kamiya, W. Yokota, K.

月(滋賀)Arakawa, T. Agematsu, I. Ishibori, H. Kashiwagi,
S. Kurashima, T. Nara, S. Okumura, K. Yoshida,

06C061 4-54

M. Fukuda,

古田祐介、打矢直之、西川宏之、芳賀潤二、“Studyon

Large-area

Uniform

Ion

Beam

S, T

佐藤隆博、及川将一、石井保行、神谷富裕

Formation Using Multipole Magnets”“集束プロトンビーム描画によるマイクロマシ

Proceedings of the 3rd Annual Meeting of Particle

ニングプロセス”

Accelerator Society of Japan and the 31th Linear

第 37 回電気電子絶縁材料システムシンポジウ

Accelerator Meeting in Japan, Sendai, Japanム、D-1、2006 年 10 月(千葉)(2006) p.913.

06C062 4-54
06C058 4-50

C

N.Miyawaki,

S.Okumura,

H.Kashiwagi,

K.Yoshida,S, T吉田栄治、西川宏之、打矢直之、古田祐介、
S.Kurashima,

I.Ishibori,Y.Yuri,

芳賀潤二、及川将一、佐藤隆博、石井保行、
神谷富裕

T.Nara, T.Agematsu, M.Fukuda,“集束プロトンビームによる高アスペクト比微“DEVELOPMENT OF THE CENTRAL REGION

細加工”

FOR CONTROL OF A BEAM PHASE WIDTH

プラスチック成形加工学会 第 14 回秋季大会

AT THE JAEA AVF CYCLOTRON”

成形加工シンポジア 06 特別セッション、A-08、Proceedings of the 3rd Annual Meeting of Particle

2006 年 11 月(岐阜)

Accelerator Society of Japan and the 31th Linear
Accelerator Meeting in Japan, Sendai, Japan－ 235 －

JAEA-Review 2007-060

06C063 4-54

S, T

古田祐介、打矢直之、西川宏之、芳賀潤二、
及川将一、佐藤隆博、石井保行、神谷富裕、“集束プロトンビーム描画による三次元構造体の作製”
春季第 54 回応用物理学会、p.780、2007 年 3月(神奈川).

06C064 4-57

E

T. Kojima, H. Sunaga and R. Tanaka,“Consistency in evaluation of a few MeV electron
dose and 60Co gamma-ray dose in radiation
processing”
Radiation Technology in Emerging Industrial
Applications,

Conference&

Symposium,

IAEA-SM-365/56, 216-219 (2003)－ 236 －

JAEA-Review 2007-060

Appendix 2
List of Related Patents
06PAT001

06PAT006

1-20

2-7

井岡郁夫（原子力機構）他神戸製鋼所、コベル

瀬古、玉田、吉井（原子力機構）

コ科研との共同出願、「金を吸着回収する吸着材の合成方法及び排「耐粒界腐食性および耐応力腐食割れに優れ

水処理」

たオーステナイト系ステンレス鋼およびその特開 2005-154973 号

製造方法」
出願番号

06PAT007

特願 2007-117981 号

2-16

玉田、八木、長澤（原子力機構）金澤（住友電

06PAT002

1-27

工ファインポリマー）

高木、小林、斉藤（トヨタ自動車）、吉田、「ポリ乳酸製熱収縮材」

八巻、浅野（原子力機構）

特願 2006-212502 号「Functional membrane and electrolyte membrane
for fuel cell and method for producing the same」,

06PAT008

2-16

PCT/JP2006/303504

金澤、川野（住友電工ファインポリマー）、
玉田、長澤、八木（原子力機構）

06PAT003

1-27「ポリ乳酸製架橋材の製造方法およびポリ乳

廣木、八巻、浅野、吉田（原子力機構）

酸製架橋材」「プロトン伝導度測定方法と装置」

特願 2006-213951 号

特願 2006-043562 号

06PAT009
06PAT004

1-27

2-16

玉田、八木、長澤（原子力機構）金澤（住友電小林(トヨタ自動車)、八巻、浅野、吉田、前川

工ファインポリマー）（原子力機構）「ポリ乳酸弾性体」「機能性膜の製造方法、及び燃料電池用電解質

特願 2006-216068 号

膜の製造方法」

06PAT010

特願 2006-317281 号

2-18

瀧上、天田（群馬県産業支援機構）、長澤、

06PAT005

2-3

八木、玉田、笠井、吉井（原子力機構）

瀬古、玉田（原子力機構）、伊藤、坂田（九州「カルボキシメチルセルロースゲルの製造方

日立マクセル）法」「高周波基盤およびその製造方法」

特願 2006-250947 号

特願 2005-359923 号－ 237 －

JAEA-Review 2007-060

06PAT011

2-18媒とするアルコール添加硫酸水溶液を使用す

瀧上（群馬県産業支援機構）、長澤、八木、る放射線誘起水素製造法」

玉田（原子力機構）

特願 2006-161019 号「カルボキシメチルセルロースを主成分とするゲルの製造方法とそのゲル」

06PAT018

4-19

特願 2007-70145 号

永石、山田、籏野、吉田（原子力機構）「固体を共存した水溶液への放射線照射によ

06PAT012

2-19

る水溶液中の強酸化性金属イオンの処理回収

八木、長澤、廣木、玉田（原子力機構）、Charito

方法」

T. Aranilla（フィリピン原子力研究所）

特開 2006-247485 号「多糖類を原料とするゲルの製造方法」

06PAT019

特願 2006-331679 号

4-19

山田、永石、籏野、吉田（原子力機構）

06PAT013

2-20「石英、アルミナなどの耐強酸性の酸化物固体

笠井昇、吉井文男（原子力機構）、湯浅淳一（積を触媒とする放射線誘起水素製造法」

水化学工業）

特開 2006-248822 号「ポリオレフィン系樹脂管の曲げ加工方法」
特願

06PAT020

2007-129566 号

4-19

山田、永石、吉田（原子力機構）

06PAT014

3-52「高レベル放射性廃棄物を線源とする放射線

鵜飼光子、下山雄平（北海道教育大学）

誘起触媒反応による水素製造法」「放射照射食品の検査方法」

特開 2006-248821 号

特願 2005-61622 号

06PAT021
06PAT015

3-53

4-25

杉本雅樹、吉川正人（原子力機構）、関修平、

藤里俊哉、山岡哲二、中谷武嗣、北村惣一郎（国佃諭志、田川精一(大阪大学）

立循環器病センター）「イオンビーム照射によるセラミックナノワ「生体組織マトリックスへの細胞播種方法」

イヤーの製造法」

特願 2005-180344 号

特開 2007-76978 号

06PAT016

06PAT022

3-54

4-25

河地有木、藤巻秀、松橋信平（原子力機構）

関修平、佃諭志、田川精一（大阪大学）、「光合成機能イメージングのための新規方法」

杉本雅樹、吉川正人（原子力機構）

特開 2007-154225 号「高分子多段ナノワイヤー及びスターバース
ト型ナノ粒子とそれらの製造法」

06PAT017

4-19

特願

山田、永石（原子力機構）「石英、アルミナなどの耐強酸性の酸化物を触－ 238 －

2007-64288 号

JAEA-Review 2007-060

06PAT023

4-49

島田、及川、加藤、佐藤、堀内、遊佐、岸、
中野（群馬大学）、佐藤、酒井、上松、福田、
荒川（原子力機構）「荷電粒子線の照準位置決定装置，その使用方
法，及び照準位置決定装置を用いた治療装置」
PCT/JP2007/050347

06PAT0244-51

吉田、田島（原子力機構）、横山（信越化学）「ECR イオン源に用いられるプラズマ閉じ込め用のミラー磁場発生装置及び方法」
特開 2006-049020 号－ 239 －

JAEA-Review 2007-060

Appendix 3
List of Related Press-Release and TV
Programs
06NP001

06NP006

2-01

4-54

平成１８年７月２８日、日経産業新聞に掲

平成１９年２月２０日、日刊工業新聞他７

載、

紙に掲載、

「ホタテ内臓捨てずに利用

無害化し肥

料などに」

「原子力機構と芝浦工大
加工

神鋼と先端素子装置開発へ」「陽子ビーム加工技術開発

06NP002

2-16

PBW で長深度原研機構など」「プロトンビームライティング

平成１９年６月２１日、２５日、２６日

製に応用

読売新聞他７紙に掲載、鋼」等

超精密金型作原子力機構－芝浦工大－神戸製「塩ビに替わる柔らかいポリ乳酸の開発に
成功－植物由来プラスチックの応用範囲を

06TV001

3-33

大幅に拡大－」

平成１８年８月３日１９時３０分、NHK 総合、[クローズアップ現代]、

06NP0032-18「残留放射線の脅威

平成１８年１２月８、１２、２１日、追う～」

日本経済新聞他８紙に掲載、「環境に優しい植物由来のゴムのような弾性ゲル体の開発に成功」、「吸水・弾力性のゲル開発」

06NP0043-01

平成１８年４月２５日、毎日新聞他８紙に掲載、「植物を紫外線に強くするメカニズム」

06NP0054-33

平成１８年８月７日、上毛新聞他４紙に掲
載、「高輝度陽電子ビームを用いて表面ナノ物
質の原子立体配列の観測に成功―陽電子で物質最表面の顕微技術が可能に―」－ 240 －～“第３の被爆”を

－ 241 －－ 242 －JAEA-Review 2007-060

Symbol used in the Appendix
Written example

06

J

173

4-42

C

①

②

③

④-⑤

⑥

①

Abbreviation of A.D. year

②

J

:

Publications in JournalC:

Publications as Proceeding

NP : Press-Release
TV :TV Programs

PA : Patent③

Reference number④

The number of research field
1

Space,nuclear and energy engineering

2

Environment conservation and resource security

3

Bioyechnology and medical application

4

Advanced materials, analysis and novel technology⑤

The number of papers⑥

Irradiation FacilitiesC

AVF Cyclotron System

T

Tandem Electrostatic AcceleratorI

Ion implanter

S

Single-ended Electrostatic AcceleratorG

Co-60 Gamma-Ray Irradiation Facilities

E

Electron AcceleratorO

Off-line－ 243 －

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