CO4-1

Small Angle Neutron Scattering Sudy of Surfactant Micelle Structures
by Utilizing KUR-SANS

K. Hara, T. Yanagino, S. Yoshioka,
M. Sugiyama1 and T. Fukunaga1
Faculty of Engineering, Kyushu University
1
Research Reactor Institute, Kyoto University
INTRODUCTION:
Hydrocolloids are composed of dispersoid and water;by the interactions between them, emerge the characteristic properties and structures. The authors have beeninterested in the nano-structures of the hydrocolloids;
and in the previous study with utilizing KUR-SANS
system, they successfully detected the alteration of thenano-scale micelle structure of sodium oleate (SO,Fig.1) with changing the ambient temperature [1],which also demonstrated the usability of the system in
the investigations of the nanostructures of hydrocolloids.
On the basis of the previous study, the authors have
performed more extensive investigations by adding another surfactant, sodium decane sulfonate (SDS, Fig.1),
as the specimen for the comparative SANS study.
EXPERIMENTS:
Prepared were 1.0 wt% of SO and 3.0 wt% of SDS
heavy-water solutions, which were sealed into respective quartz cells. After having been left intact for 24hours at room temperature, observed were their small
angle neutron scattering (SANS) profiles (Fig.2). Also,
measured were the SANS profiles of the SO solutions
with different concentrations (Fig.3). The SANS experiments were performed with a KUR-SANS spectrometer installed at Kyoto University Reactor, Kumatori, Osaka, Japan.
RESULTS AND DISCUSSIONS:
Figure 2 shows the SANS profiles of 1.0 wt% of SO
and 3.0 wt% of SDS heavy-water solutions, demonstrating the different features in their nano-structures.
The relatively smaller structure in the SDS solution cancome from their highly ionized hydrophilic heads andshort-and-strait hydrophobic tails compared with SO
composed of the weak-acid head and long-and-bent tails.
From Fig.3, one can perceive a peak in the SANS profiles of SO with the concentrations above CMC, whichindicates the micelle formation. The shape of the SANS
profiles of SO in Figs.2 and 3 is characteristic and canbe come from some complicated nano-structure. Detailed investigations are in preparation.
REFERENCE: [1] KURRI Prog. Rep. 2010, CO4-1, p. 210.

Sodium oleate(SO)Sodium decane sulfonate(SDS)

Fig.1 Chemical structures of the surfactants
investigated in the present study.

Fig.2 SANS profiles of SO and SDS
measured by KUR-SANS system.

Fig.3 SANS profile change with SO-concentration
measured by KUR-SANS system.

採択課題番号 23008 アクリルアミド系ゲルのナノ構造とダイナミクスの高分子網目・溶媒コンポーネント依存性（九大院工）原 一広、柳野 智、吉岡 聰（京大原子炉） 杉山正明、福永俊晴

共同通常

CO4-2

Radiation-induced Luminescence for Applying to Retrospective Dosimetry

H. Fujita, Y. Nakano1 and T. Saito1
Nuclear Fuel Cycle Engineering Laboratories, JAEA
1
Research Reactor Institute, Kyoto University
INTRODUCTION: It is well known that natural
quartz exposed to ionizing radiation emits thermoluminescence (TL) such as ultra-violet TL (UVTL), blue TL(BTL) and red TL (RTL), and optically stimulated luminescence (OSL) [1]. The luminescence phenomena havebeen used for retrospective dosimetry (e.g. [2, 3]). However, the reason for the emission mechanisms of theirluminescences except for BTL [4] from Japanese quartz
has not yet been well explained. In this study, the emission mechanisms of UVTL, RTL and OSL were investigated in conjunction with various radiation-induced phenomena after annealing treatments of quartz samples,
involving TL OSL and electron spin resonance (ESR)
measurements.
EXPERIMENTS: Coarse quartz grains (150~250 m)collected from surface soils in Japan were extracted by ageneral treatment of 6M hydrochloric acid (HCl) and 6M
sodium hydroxide (NaOH) followed by concentratedhydrofluoric acid (HF) and sieving treatments. Further
purification of the quartz grains was performed by handselection for the sake of elimination of feldspar grains as
low as possible under a microscope. The extracted quartz
samples were annealed at 500 and 800 ºC in an electric
furnace. After the annealing treatment, the quartz samples
were irradiated with 60Co source at room temperature at
Kyoto University Research Reactor Institute (KURRI).
After the -ray irradiation (the applied dose: 1 kGy), thesample was stored at room temperature for one day toeliminate afterglow effect in dark room. The ESR measurement was carried out using an ESR spectrometer (JeolLtd., JES-TE 200) at room temperature and −196 ºC,
respectively. Prior to the ESR measurements, the quartz
samples were annealed for 1 min at 50 ºC intervals ranging from 150 to 300 ºC as preheat treatment. After the
ESR measurements, all luminescence measurements were
performed using a JREC automated TL/OSL-reader system installed with a small X-ray irradiator (Varian,
VF-50J tube). All preparations were carried out under
dim red light.
RESULTS: As shown in the previous report, the ESR
signals of Ti-centers ([TiO4/H+]0, [TiO4/Li+]0 and[TiO4/Na+]0), Al-centers and RT-centers were detected inboth quartz samples annealed at 500 and 800ºC. ESR

採択課題番号 23010

signal intensities of Ti-centers and Al-centers were decreased with the preheat temperatures but intensities of
RT-centers were changed with the temperatures, randomly.
UVTL and RTL glowcurves, and OSL decay curves
were measured using all kinds of quartz samples. TheUVTL and the RTL intensities were integrated in whole
region of heating temperature. The OSL signal intensity
was estimated by integrating the counts in the first 1 s ofthe decay curve after subtracting the average backgroundestimated from the data in the last 2 s of the OSL curve.
Fig. 1 shows the changes of each luminescence intensity
normalized to the intensity at 150 ºC. The intensities of
the UVTL and the RTL decreased with increasing preheat

Fig. 1. Tendency of UVTL, RTL and OSL intensities
with several preheat temperatures. Each luminescenceintensity was normalized to the intensity at 150 ºC.
temperatures. On the other hand, the intensities of OSL
increased up to 250 ºC and then decreased to 300 ºC. The
reason why the OSL intensity increased up to 250 ºC is
the re-trapping effect influenced by the preheat treatment.
In these results, the UVTL could be related to ESR signals of the Ti-centers but the other luminescences could
not be related to ESR signals. Moreover, it is supposedthat ESR signals of the Al-centers and the RT-centers
have no relationship with TL and OSL.
Further work is necessary to identify luminescencemechanism using ESR measurement and annealing experiment.
REFERENCES:[1] T. Yanmaguchi et al., BUNSEKI KAGAKU 52(2003) 787-793.
[2] T. Hashimoto et al., Radioisotopes 51 (2002) 10-18.
[3] T. Hashimoto et al., Radiat. Meas. 41 (2006)
1015-1019.
[4] T. Hashimoto et al., BUNSEKI KAGAKU 51 (2002)
527-532

緊急時被ばく線量測定を目指した
放射線誘起ルミネッセンスの基礎的研究（原子力機構、核サ研）藤田博喜、（京大・原子炉）中野幸廣、齊藤 毅

共同通常

CO4-3

Neutron Irradiation Effects of Superconducting Magnet
Materials at Low Temperature

T. Nakamoto, M. Yoshida, T. Ogitsu, Y. Makida,
K. Yoshimura, S. Mihara, M. Sugano, H. Nishiguchi,
M. Iio, Y. Kuno1, M. Aoki1, A. Sato1, T. Itahashi1, Q. Xu2,
K. Sato2, Y. Kuriyama2, B. Qin2, Y. Mori2 andT. Yoshiie2
J-PARC Center, KEK
1
Department of Physics, Osaka University
2
Research Reactor Institute, Kyoto University
INTRODUCTION:
The superconducting magnets
will be subjected to a high neutron fluence of 1021 n/m2
or higher in the operation life time in the high energy
particle physics experiments with higher proton beam
power, such as a high luminosity upgrade of the LHC at
CERN and the muon source for the COMET experiment
at J - P A R C. Since electrical resistivity of a stabilizer at
low temperature, which is very sensitive to neutron
irradiation, is one of the important parameters for thequench protection of the magnet system. Measurement on
aluminum stabilizer with additives of Y taken from theprototype superconducting cable as well as reference
samples (5N pure aluminum and OFHC) was performed.
EXPERIMENTS: The irradiation test was carried out
at a low temperature irradiation facility (LTL) at E-4 line
of
KUR.
A
samplewithdimensionsof
1 mm x 1 mm x 70 mm was cut from the aluminumstabilizer(RRR~350)ofthesuperconductor
manufactured by Hitachi Cable. The RRR of 5N
aluminum and OFHC are 3000 and 300, respectively.
The electric resistance was measured by a 4-wire method
employing a Keithley 6221 current source and a Keithley
2182A voltmeter. Polyimide-coated wires were attachedat both ends of the sample as current feeds and voltage
sensing wires were attached with the interval of 45 mm
on the sample by crimping with copper sleeves. A currentof 100 mA was fed into the sample. The polarity waschanged at a frequency of 10 Hz and the readouts wereaveraged over 100 cycles. The temperature was measured
using a thermocouple of Au(Fe) and Chromel, since the
Cernox sensor CX-1050-SD shows a temperature drift
during neutron exposure maybe due to the irradiation
damage. The thermocouple and the Cernox sensor andplaced just behind the samples to measure thetemperature of the helium gas.
RESULTS: Two aluminum stabilizer samples were
irradiated in Nov. 2011. After cooling down to 10 K, thereactor was turned on to a power of 1 MW. The estimatedfast neutron fluence in 52 hour operation is 2.6x1020 n/m2.
Measured resistance and temperature changes during theirradiation are shown in Fig. 1. The temperature jumped
from 10 K to 12 K at the beginning due to radiation fromthe reactor core. During exposure thermocouple indicatesFig. 1.

Resistance and temperature of the aluminumstabilizer sample during irradiation.

stable temperature while the Cernox sensor readout drifts
up to 15 K maybe due to irradiation damage. The sample
resistance increased from 4.0 μΩ to 7.3 μΩ in 52 hours
of exposure. Another sample changes from 3.6 μΩ to
6.6 μΩ. The resistance changes of the samples
correspondtotheinducedresistivityofρi = 0.067-0.070 nΩm. The induced resistance seems toincrease in proportion to the neutron fluence duringexposure by a rate of dρi = 0.027 nΩm per 1020 n/m2. The
5N pure aluminum and OFHC samples are irradiated in
Sep. 2011 at KUR. Due to troubles on data acquisition
system, some data was lost and there exist noise in somepart. The slope of resistance changes indicatesdρi = 0.027 nΩm per 1020 n/m2 for 5N pure aluminum,and dρi = 0.008 nΩm per 1020 n/m2 for OFHC.
SUMMARY AND PROSPECT: A series of neutron
irradiation tests at Kyoto Univ. Research Reactor has
started, with the aim of R&D for radiation hardsuperconducting magnets. The electric resistivity inaluminum stabilizer for superconducting cable isinvestigated in this work. High strengthened aluminumstabilizer with yttrium doped were tested in 2011.
Annealed 5N pure aluminum and OFHC were also
irradiated as a reference data. Regardless of additives ortransition by cold work, all the aluminum sample shows
consistentdegradation
correspondingtotheneutron-induced resistivity. The OFHC sample indicatesless degradation by a factor of 3 than those of aluminum
samples. While irradiation damage on the electricalconductivity of aluminum can recover by thermal cycling
to the room temperature perfectly as observed in theprevious work, irradiation damage in copper could
remain after annealing at room temperature. Anotherirradiation test is planned to measure whether the
degradation by iterative irradiation could be accumulated
in copper.

65`lQ23013
b+US@8 DL 3&N*(n"d.poTq?02ZIcEP/!P_!AK :^=4[f>R%
m,i(p$g$ OqfY'j=GH\<BFh9Ja#;P]Vpe$ &MqX)7G1\WC-k7

CO4-4

Absorption Spectroscopy with the Coherent THz Radiationfrom Linac Electron Beams

S. Okuda, T. Kojima, S. Shimomura and T. Takahashi1of the measurement are described in ref. 3.

Radiation Research Center, Osaka Prefecture University
Research Reactor Institute, Kyoto University

1

INTRODUCTION: The coherent synchrotron andtransition radiation (CTR) from electron bunches of alinear accelerator (linac) has continuous spectra in a
submillimeter to millimeter wavelength range at extremely high peak-intensities. The coherent radiation(CR) light sources developed were applied to absorption
spectroscopy [1-4] especially for matters with relatively
strong light absorbance.
The absorption spectroscopy system using the CTR
from the electron beams of the 45 MeV L-band electron
linac was established at KURRI [5]. The CR has
high-intensity pulsed electric field. This kind of lightpossibly excites matters in a short period. The change ofthe transmittance was observed in the measurements
made by changing the light intensity [6]. However, theexperimental configurations were not adequate for the
study. In this work the previous absorption spectroscopy
system has been slightly modified for such experiments.
EXPERIMENTAL METHOD: The new experimental
configurations modified for the absorption spectroscopy
investigating the effect of light intensity are schematically shown in Fig. 1. The output light from a light sourcechamber was focused at a light collimator 8 mmφ in diameter. The spectrum of light after passing through thesample was measured with a Martin-Puplett type interferometer and a liquid-He-cooled silicon bolometer. In theprevious experimental configurations the sample was
located on the light path between the interferometer andthe detector [5]. The schematic diagram of the interferometer and the typical interferogram obtained by the measurement is shown in Fig. 2. The peak intensity of thepulsed light after the interferometer changes during themeasurement.

Fig. 1. Schematic diagram showing the new configurations for absorption spectroscopy using the CTR.
In this system the wavenumber resolution was 0.2 cm-1.
It took about 5 minutes in a measurement. The spectrum
was sufficiently stable during the measurements within±2-3% in a wavenumber range of 4-12 cm-1. The details

Fig. 2. Schematic diagram of the Martin-Puplett typeinterferometer and the typical interferogram obtained by
the measurement.
RESULTS AND DISCUSSION: In the previous experimental configurations the wavenumber dependence ofthe transmittance of light was measured for various kindsof matters. For the sample of SiO2 nano particles thetransmittance became higher by 20-30% at a light intensity two orders of magnitude higher than the ordinary one.
These results seem to suggest some change in the conditions of the sample induced by the pulsed CTR. Measurements have been made under the new experimental
configurations shown in Fig. 1. We are analyzing these
new results obtained by the measurements.
In order to investigate the transient phenomena induced by the pulsed CR the pump-probe experimental
system was established in Osaka Prefecture University.
REFERENCES:[1] T. Takahashi, T. Matsuyama, K. Kobayashi, Y. Fujita,
Y. Shibata, K. Ishi and M. Ikezawa, Rev. Sci. Instrum.
69 (1998) 3770.
[2] K. Yokoyama, Y. Miyauchi, S. Okuda, R. Kato and T.
Takahashi, Proc. 20th Int. Free-Electron Laser Conf.
(Williamsburg, USA, 1998) II 17-18.
[3] S. Okuda, M. Nakamura, K. Yokoyama, R. Kato and
T. Takahashi, Nucl. Instrum. Meth. A445 (2000) 267.
[4] S. Okuda, M. Takanaka, M. Nakamura, R. Kato, T.
Takahashi, S. Nam, R. Taniguchi and T. Kojima,
Radiat. Phys. Chem. 75 (2006) 903.
[5] S. Okuda and T. Takahashi, Infrared Phys. Technol.
51 (2008) 410.
[6] S. Okuda and T. Takahashi, Proc. 35th Int. Conf. on
Infrared, Millimeter and Terahertz Waves (2010, Rome,
Italy), IEEE Xplore 10.1109/ICIMW.2010.5612474.

採択課題番号 23022 ライナック電子線からのコヒーレントテラヘルツ放射による吸収分光（阪府大・地域連携）奥田修一、小嶋崇夫、下邨広元（京大・原子炉）高橋俊晴

共同通常

CO4-5

State Analyses of Novel Gold Clusters by 197Au Mössbauer Spectroscopy

K. Konishi, Y. Shichibu, Y. Kamei, H. Ohashi1 and Y.
Kobayashi2
Faculty of Environmental Earth Science, Hokkaido University
1
Faculty of Arts and Science, Kyushu University
2
Research Reactor Institute, Kyoto University

not be accurate because of shape of spectra because of
shapes of these spectra.
In the near future, theMössbauer measurements of similar gold cluster compounds will help us to analyze details of assignment inthese spectra.

(a)
1.00

EXPERIMENTS: Ligand-coordinated gold clusters（[Au8(dppp)4](NO3)2 and [AuCl2(dppp)4](NO3)2, dppp =1,3-bis(diphenylphosphino)propane ） were prepared by
the similar procedure reported before [1]. The chemical
state of AuN prepared was determined by 197Au
Mössbauer spectroscopy (home-made equipment). The
197
Pt isotope (T1/2 = 18.3 h), a γ-ray source feeding the77.3-keV Mössbauer transition of 197Au, was prepared byneutron irradiation of isotopically enriched 196Pt metal at
the Kyoto University Reactor. The absorbers were particle specimens. The source and specimens were cooledwith a helium refrigerator. The temperature of thespecimens was in the range 8 – 15 K. The zero velocity
point of the spectra was the peak point of pure bulk gold.
The spectra for all the solid samples were fitted with asingle Lorentzian function.
RESULTS: Figure 1 shows 197Au Mössbauer spectra of[Au8(dppp)4](NO3)2 and [AuCl2(dppp)4](NO3)2, which
superposing two components c1-c2 and c3-c4, respectively. Table 1 shows Mössbauer parameters for eachcomponent of these two cluster compounds. The spectrum of [AuCl2(dppp)4](NO3)2 was different from that of[Au8(dppp)4](NO3)2, suggesting that Au-Cl bonds have astrong effect to Mössbauer parameters. The values of IS
and QS in c1-c4 doublets are quite large, because thevalence of gold is close to Au(I) and it has bonds to Cl or
P. However, the resolutions of these peaks may or may

採択課題番号 23024

c1
Relative Transmittance

INTRODUCTION: We have studied to prepare novel
gold clusters because of their unique optical, electronic,
and catalytic properties [1]. However, it is difficult toobtain such as electronic state of gold by X-ray single
crystal structural analysis. It is important to obtain thebond information between gold cluster and ligand ascluster science and catalytic chemistry.
The aim of this study was to investigate the chemical
state of gold in the ligand-coordinated gold clusters prepared.

0.99

c2
0.98
-8

0

8

16

(b)
1.00

c3
c4
0.99
-8

0

8

16
-1

Velocity / mm sFig. 1. 197Au Mössbauer spectra of [Au8(dppp)4](NO3)2(a) and [AuCl2(dppp)4] (NO3)2 (b).
Table 1.

Mössbauer parameters for each component
IS
QS
P
FWHM
Component/mms-1/mms-1/%/mms-1
c1
4.31
7.84
42.3
2.04
(a)
c2
2.95
6.17
57.7
2.04
c3
2.79
5.53
24.5
2.13
(b)
c4
3.24
7.17
75.5
2.13

REFERENCE:[1]
Y.
Shichibu
6(2010)1216-1220.

and

K.

Konishi,small,

新規金クラスター化合物の Au-197 メスバウアー分光法による
共同通常
状態解析
（北大院・地球環境）小西克明、七分勇勝、亀井優太朗 （九大・基幹教育院）大橋弘範（京大・原子炉）小林康浩

CO4-6

Coherent Excitation of Superionic Conduction

Department of Electronic Engineering, Tohoku Gakuin
University
1
Research Reactor Institute, Kyoto University

ABSORPTION COEFFICIENT(cm -1)

RESULTS: Figure1 shows change of transmittance intensity of a thin plate of RbAg4I5. Transmittance spectrum in external field divided by that without external
field is shown. Intensity decreased at 6 cm-1 and 10 cm-1.
Signal intensity was small around 10 cm-1 because ofstrong absorption; therefore, only decrement around 6
cm-1 is sure. This change recovered by removing theelectric field. This means that the change is due to ionic
conduction or secondary effect of the conduction, such aschange of density of conduction ions. There still may be
due to electrochemical reaction around electrodes.
Fig. 2 shows absorption spectra of RbAg4I5 and
RbCu4Cl3I2 crystal. No characteristic structure around 6
and 8cm-1, which existed in glasses[1, 2], was observedin these crystals. This means that such absorption bands
observed in glassy samples are related with random
movement of conduction ions.

採択課題番号 23026

1
0.98
0.96

RbAg 4I5 300K

0.94

6
8
10
WAVE NUMBER (cm -1)

12

Fig. 1. Change of transmittance of RbAg4I5 by applying external electric field. Measurement field wasrestricted around electrode by near filed spectroscopic method.

EXPERIMENTS: Thin and thick plates of RbAg4I5
and RbCu4Cl3I2 between quartz windows were preparedfrom melt of these crystals. Transmittance spectra of coherent millimeter wave were measured by a Martin-Puplett type interferometer. Near field spectroscopic
measurements were done by restricting field with lightcone waveguide. Near electrode region was observed to
study external field effect clearly. External electric field
was applied by standard type function generator. Amplitude of the sinusoidal electric field was 3.3Vpp and frequency was 1kHz. Gold thin wire was used as electrodes.

REFERENCES:[1] T. Awano and T. Takahashi, Journal of Physics: Conference Series 148 (2009) 012040.
[2] T. Awano and T. Takahashi, J. Phys. Soc. Jpn. 79
Suppl. A (2010) 118.

1.02

4

ABSORPTION COEFFICIENT(cm -1)

INTRODUCTION: Movement of ions is not in phaseand frequent scattering by other mobile ions seems todecrease the ionic conductivity. If coherent excitation ofionic movement by coherent external electric field occurs,
ionic conductivity seems to increase drastically. Coherent
THz wave from LINAC of KURRI is so strong that theexcitation effect is expected to be observed. We havemeasured millimeter wave absorption spectra of silver
halides - silver phosphate glasses to investigate the existence of such a collective movement of conductionion[1, 2]. In this study, it is tried to induce direct excitation of coherent ionic movement of conduction ion.

INTENSITY RATIO (no field = 1)

T. Awano and T. Takahashi1

100

RbAg 4I5
300K-77K
230K-77K
150K-77K

50

0

4

6
8
10
WAVE NUMBER (cm -1)

12

50
40

RbCu4Cl3I2

30

300K-77K
230K-77K
150K-77K

20
10
0

4

6
8
10
-1
WAVE NUMBER (cm )12Fig. 2. Increment absorption spectra of RbAg4I5 and
RbCu4Cl3I2. Absorption spectra at each temperatureare subtracted by that at 77 K.

超イオン導電体におけるコヒーレントミリ波誘起イオン伝導の検証（東北学院大・工）淡野照義 （京大・原子炉）高橋俊晴

共同通常

CO4-7

One-dimensional Imaging Microscopy of a Cancer Tissue in the Terahertz
Region using Coherent Transition Radiation

T. Takahashi, T. Iizuka 1 and S. Kimura 2, 1

[4] T. Takahashi, et al., Rev. Sci. Instrum. 69 (1998)
3770.

Research Reactor Institute, Kyoto University
School of Physical Sciences, The Graduate University
for Advanced Studies
2
UVSOR Facility, Institute for Molecular Science
1

INTRODUCTION: The basic properties of thetechnique of near-field THz-wave microscopy has been
experimentally investigated by our group [1-3]. The
technique is a characteristic application of coherent
radiation emitted from a relativistic electron beam, andprovides high spatial resolution below the diffraction
limit. In the present report we have performed the onedimensional imaging microscopy of a cancer tissue using
a near-field aperture probe with coherent transition
radiation (CTR) as the demonstration.
EXPERIMENTAL PROCEDURES: The experiment
was performed at the coherent radiation beamline [4] atthe 40-MeV L-band linac of the Research Reactor
Institute, Kyoto University. The width of the macro pulse
and the repetition rate of the electron beam were 47 ns
and 46 Hz, respectively. The charge of a bunch was 1.2
nC. The THz-wave source was CTR emitted from analuminum foil with a thickness of 15-m. The thicknessof a cancer tissue was 50 m and was put between two
sheets of Kapton film 25 m thick as shown in Fig. 1.
The size of the aperture of the scanning probe was 775
m . The spectra of CTR were measured by a Martin Puplett type interferometer at each scanning position of
the sample.
RESULTS: The observed one-dimensional imaging
spectra at the positions along the solid line in Fig. 1 wereshown in Fig. 2. The dark color in this figure represents
the large absorption by the sample. The absorption can beseen at around 11 cm-1. Similarly, the observed spectra at
the position along the broken line in Fig. 1 were shown in
Fig. 3. There seems to be the absorption at around 13cm-1.
The origin of this absorption is not clear at present.

Fig.1. The photograph of the sample. The cancer tissue
was put between two sheets of Kapton film.

absorption

Fig.2. Observed spectra of transmitted THz wave at thepositions along the solid line in Fig.1.

absorption

ACKNOWLEDGMENTS: This work was partly
supported by Quantum Beam Technology Program of
MEXT, Japan.
REFERENCES:[1] T. Takahashi, et al., KURRI-PR 2008 CO4-10.
[2] T. Takahashi, et al., KURRI-PR 2009 CO4-8.
[3] T. Takahashi, et al., KURRI-PR 2010 CO4-7.

Fig.3. Observed spectra of transmitted THz wave at thepositions along the broken line in Fig.1.

採択課題番号 23027 コヒーレント遷移放射を用いたミリ波近接場イメージング
分光法に関する研究（分子研）木村真一、飯塚拓也（京大・原子炉）高橋俊晴

共同通常

	
 

CO4-8

Trial use of KUR-SANS for Characterizing Precipitates in Steels

M. Ohnuma1, Y. Oba1, 2, P.Kozikowsky1,3 and M. Sugiyama2
1

National Institute for Materials Science
Research Reactor Institute, Kyoto University
3
Warsaw University of Technology
2

INTRODUCTION: Precipitates in alloys often play
an important role for modifying their properties in both
structural and functional materials. Precipitation hardening is one of the key technology in structural materials
and now widely used in the commercial products. Number density and average size of precipitates are dominantparameter for the level of increment in the mechanicalproperties. Though small-angle neutron scattering(SANS) is advantageous for obtaining such information in bulk form, shortage of machine time is serious
problem for spread applications in steel industries. In
addition, it is easy to prepare large samples that are stableat room temperature for the case of steel. Taking theabove conditions into account, usage of small neutron
source including both continuous and pulse is an urgent
requirements for industrial applications. In this study, weapplied KUR-SANS for the measurements of high-q
SANS of steels for evaluating precipitates.
EXPERIMENTS: The steel with adding V to the
S45C based compositions were measured using
KUR-SANS. Wavelength used in the measurements is
0.26nm. Sample thickness is about 2 mm. Glassy carbon
that is widely used as secondary standard for absoluteunit was also measured. The obtained profiles werecompared to the profiles measured using SANS-J-II installed in JRR-3. In this case, used wave length is 0.6nm.

Fig. 1 SANS and SAXS profiles of glassy carbon
measured by KUR-SANS and SAXS at ANL
採択課題番号 23028	
 RESULTS: Figure 1shows a SANS profile of Glassy
carbon measured for 4hours at the running conditionof 1MW of KUR. The profile shown in solid line is theone measured by small-angle X-ray scattering(SAXS)in Argonne National Labo(ANL), indicating that thedata obtained in KUR is fine in the range of 0.3 to 3
nm-1 which is the optimum q-rage for characterizing
nano-size precipitates. Figure 2 shows SANS profilesof the steel with Vanadium addition. The profiles were
measured under the magnetic field of 0.5T to separate
nuclear and magnetic scattering component. Although
the q-range is same with the profiles of glassy carbon,
profile shapes are not same with the one measured
using SANS-J-II. Recent measurements using TAIKAN installed in J-PARC shows similar distortion of
the profiles when the wave length below 0.4nm. Because the value correspond to the Bragg edge of 110
plane that is the maximum lattice plane in the bcc-Fe,
the distortion of the profiles compare to the one measured using cold neutron with larger than Bragg cutoff
wave length, can be attributed to the multiple diffraction.
Based on these results, we are now planning to use
neutron with the wavelength larger than 0.4nm. Enlarging beam size from 5mm (present) to 10mm indiameter can cover the smaller neutron flux aroundthis wavelength and make KUR-SANS useful tool inthe steel research.

Fig. 2 SANS profiles of the steel with V measured
by KUR-SANS and SANS-J-II at JRR-3

SAXS と SANS のコントラスト差を利用した組成情報を含むサイズ評価法の確立	
 	
 （物材機構）大沼正人,	
 大場洋次郎、（京大原子炉）杉山正明	
 共同通常

CO4-9Encapsulation of Hydrogen Atom into Metal Complexes
8sing Silsesquioxane Ligand with Cage Structure

Y. Okaue, T. Yokoyama, H. Ohashi1 and F. Yoshimura
Department of Chemistry, Faculty of Sciences, Kyushu
University
1
Faculty of Arts and Science, Kyushu University
INTRODUCTION: Trimethylsilylated silsesquioxane,
Q8M8 ([(CH3)3SiO]8(SiO1.5)8), is a member of thecage-shaped oligosilsesquioxanes with cubic framework
called double four-ring (D4R) structure as illustrated inFig. 1. Upon 60Co γ-ray irradiation at room temperatureon Q8M8, stable hydrogen atom is encapsulated in D4R
cage for the period of several years. The encapsulationand stabilization of hydrogen atom in D4R cage wereconfirmed by ESR spectroscopy. The hydrogen atom
encapsulated in D4R cage of silsesquioxane interacts
magnetically with paramagnetic oxygen molecules outside D4R cage to change ESR signal intensity and saturation behavior.[1] The purpose of this study was preliminary research for interactions between metal ions andencapsulated hydrogen atom within single molecule byintroducing D4R cage structure of silsesquioxane to theligand for metal ions. In this research, Schiff baseligand was used to form stable complexes with many
metal ions easily.
R1
R2
O
O Si
O
Si
R1
O
Si
Si R1
O
O
O
O
Si
R
Si O
R1
Si O
Si O
O
R1
R1

Fig. 1.

RESULTS: Ligand L1 was obtained as yellow powder.
The maximum yield was ca. 40%. Light yellow Zn(II)complex was obtained as Zn(L1)2 in a 54% yield. Dark
green Cu(II) complex was also obtained as Cu(L1)2 in a
77% yield.
ESR spectrum of the irradiated L1 was shown in Fig. 2
and ESR spectrum of the irradiated Zn(L1)2 was shownin Fig. 3. Characteristic two hyperfine lines separated
with about 50 mT due to hydrogen atom nucleus (I=1/2)
were observed in these spectra. It was concluded thatligand L1 and the complex, Zn(L1)2, can encapsulate hydrogen atom in the D4R cage of silsesquioxane unit. On
the other hand, ESR spectrum of the irradiated Cu(L1)2
was typical spectral pattern due to Cu(II) species asshown in Fig. 4. Signals due to encapsulated hydrogen
atom were also observed in enlarged spectrum, slightly.
REFERENCE:[1] R. Sasamori, Y. Okaue, T. Isobe and Y. Matsuda, Science, 265 (1994) 1691-1694.

Q8M8 ; R1, R2 = OSi(CH3)3
T8iBu7Ap ; R1 = CH2CH(CH3)2R2 = CH2CH2CH2NH2
L1 ; R1 = CH2CH(CH3)2
R2 =

N

286

Fig. 2.

336

Magnetic Field / mT

386

ESR spectrum of irradiated L1.

HO

D4R cage structure of silsesquioxanes.

EXPERIMENTS: New Schiff base ligand, L1, wassynthesized by condensation of salicylaldehyde and
T8iBu7Ap, which is commercially available silsesquioxane with D4R cage structure as illustrated in Fig .1.
L1 and zinc(II) acetate dihydrate were stirred in methanol
at 60 °C for 2 h. The resulting light yellow solution wasconcentrated under reduced pressure and cooled to room
temperature. Zn(II) complex with L1 was produced aslight yellow powder. In a similar manner, Cu(II) complex was also obtained as dark green powder. Characterizations were made by IR and 1H NMR spectroscopy
and elemental analyses. Powder samples of L1 and thecomplexes with Zn(II) and Cu(II) were irradiated with
γ-ray under air at room temperature in 60Co γ-Ray Irradiation Facility at Kyoto University Research Reactor
Institute. Irradiated samples were recrystallized fromhexane. X-band ESR spectra for these recrystallized
samples under air were measured on a JEOL JES-FA200
spectrometer at room temperature.

286

Fig. 3.

261

Fig. 4.

336

Magnetic Field / mT

386

ESR spectrum of irradiated Zn(L1)2.

336

Magnetic Field / mT

411

ESR spectrum of irradiated Cu(L1)2.

採択課題番号 23031かご型シルセスキオキサン配位子を用いた金属錯体への水素原子包接 一般通常
（九大院・理）岡上吉広、横山拓史（九大・基幹教育院）大橋弘範（九大・理）吉村富治郎

Tritium Release Behavior from Li4SiO4 doped with Ti

Cold Trap(Molecular sieve-5A)

Volumes of ionizationchambers are 66cm3 each other.

10000ppm
H2/N2Gas

I.C.2

1000ppmH2/N2gas
or dry N2 gas

I.C.1
Bubbler

Fig.1. Schematic diagram of experimental apparatus.

3

240

1200

(a)

210
180

1000
Temperature

150

800

120

HT+HTO

600

90
HT

60

400

30

200

0
-30

0

2

4

6

0

Time (h)

240
1200

(b)

210
180

1000

Temperature

150

800

HT+HTO

120

HT

90

600

60

400

30
200

0
-30

Temperature (K)RESULTS: Figure 2 shows comparison of experimental tritium release curves for the Li4SiO4 samples
irradiated for 30 minutes with neutron flux with 5. 51014
cm-2s-1 [1/cm2s]. The sweep gases of 1,000 ppm H2/Ar
gas were used in the experiments. Comparison of Figs.
2(a) and (b) indicates that tritium is released at lower

Sample Bed

Temperature (K)EXPERIMENTS: The titanium-doped Li4SiO4 ceramic
breeder materials were prepared and donated by Karlsruhe Institute of Technology (KIT). These ceramic
breeders with catalytic metals encapsulated in a quartz
tube were irradiated in Kyoto University Research Reactor (KUR) in the thermal neutron with the flux of 5.
51014 cm-2s-1 in the He atmosphere.
Release curves of bred tritium from the breeder pebbles were obtained using the out-pile temperature programmed desorption techniques. The experimental apparatus is schematically shown by Figure 1. The volumes ofionization chambers are 66 cc and the time constant for
replacement of the gas inside the chambers [volume] /[flow rate] is 40 seconds. The first ionization chamber
was used to measure the total tritium concentration andthe second chamber placed after a water bubbler wasused to measure that of molecular form tritium in thepurge gas, respectively.
Water vapor was introduced to the purge gas at the inlet of the ionization chamber when dry nitrogen gas or
nitrogen with hydrogen gas was used as the purge gas tominimize the tritium memory effect according to the result obtained in the previous works.

CuO

Concentration of released tritium (Bq/cm )INTRODUCTION: The effect of titanium on the tritium
release from Li4SiO4 ceramic breeder material was investigated. Titanium was doped in Li4SiO4 during the fabrication process so-called melt-spraying method. Tritium
release curves were obtained in a series of experiments
carried out using the out-of-pile temperature programmed desorption (TPD) technique. Tritium release
curves obtained for solid breeders with different titanium
composition were compared to examine the effect of catalyst metal on tritium release.

relatively temperatures when titanium was doped to the
Li4SiO4 breeder material. With regard to the chemical
form of tritium, almost all of the tritium was released as
HTO for the both samples.

3

K. Munakata, K. Wada and T. Takeishi1
Department Faculty of Engineering and Resource Science, Akita University
1
Graduate School of Engineering Science, Kyushu University

Concentration of released tritium (Bq/cm )CO4-10

0

2

4

6

0

Time (h)Fig. 2. Tritium release curves.
(a) Li4SiO4 ceramic breeder material(b) Li4SiO4 ceramic breeder material
doped with titanium
採択課題番号 23033
核融合炉トリチウム増殖材料および中性子増倍材料からの一般通常
トリチウムの放出挙動の解明（秋田大･工学資源）宗像健三、和田孝平 （九大･工学研究員）竹石敏治

CO4-11

Neutron Irradiation Effect on Superconducting Magnet Materials

A. Nishimura and M. Sakamoto1

EXPERIMENTS: The insulation sample (a kind of
GFRP) was hand-made by laminating a glass fiber clothand a polyimide film followed by impregnation of theblended resin. The size of the sample was 10 mmW x 15
mmL x 2.5 mmt. After the neutron irradiation at JRR-3,
JAEA, or the gamma ray irradiation with 60Co, the3-point bending spanning 12.5 mm was carried out at 77
K and the interlaminar shear strength (ILSS) was evaluated. As for the superconducting strands, the 14 MeV
neutron irradiation was carried out at FNS, JAEA, andthe superconducting properties were measured using 28 T
superconducting magnet at HFLSM, Tohoku University.
RESULTS: The ILSS results are shown in Fig. 1. CTD
and MCE indicate the Cyanate ester and EP indicates the
epoxy, and the blend ratio was varied. It should be notedthat the lower fraction of the cyanate ester brings theILSS (MPa)INTRODUCTION: The construction of a large scale
plasma device, such as ITER or JT-60SA, is undergoing.
These devices will perform Deuterium-Tritium (D-T) or
D-D reaction and generate a lot of fusion neutrons with
14 MeV. Some fusion neutrons will penetrate the blankets
or stream out of the ports and reach the superconducting
magnets. The superconducting magnets consist of thestabilizer such as high purity copper and aluminum, theelectric insulation materials, the superconducting materials and the structural materials. The stabilizer will carry
the running current when the superconducting material
becomes normal by temperature rise. The electric resistance of the high purity copper and the aluminumchanges after the neutron irradiation (> 0.1 MeV) of order of 1019 to 1020 n/m2. The insulation materials are theepoxy resin basis. To improve the neutron and gamma ray
irradiation resistance, the cyanate ester blended with the
epoxy has been developed for the ITER superconducting
magnets. In case of ITER, the neutron fluence of 1.0 x1022 n/m2 is a design value. Some typical results will bepresented later. Regarding the superconducting material,
the changes in the critical current and the critical temperature of superconducting strands by the neutron irradiation have been investigated and the study on the criticalmagnetic field started. The recent results will be shown
below. The irradiation effect on the structural material
such as Type 316L stainless steel has been investigated
and the change in the mechanical properties has beenfound in the range of the neutron fluence of order of 1024
to 1025 n/m2.

70

CTD: 100 for JRR-3 Co-60 irrad.
irradiation

60

CTD: 100

JRR-3 irrad.
(1.0x1022)(n/m2)

50
CTD/EP: 40/60

4030

MCE/EP: 30/70

20

CTD/EP: 20/80

10

EP+D230

77 K(1.0x1021)(n/m2)

0
Non-irrad.
10-3 10-2 10-1 100 101 102
Dose (MGy)103

Fig. 1 Relation between ILSS at 77 K and dose.

200
Critical current (A)Department of Helical Plasma Research, National Institute for Fusion Science
1
School of Physical Sciences, Sokendai

80

150

1.78x1021(RT)
2.65x1021(RT)

Non-irrad.
3.52x1020(4.5K)

100

0

Nb3Al

1.78x1021 (RT)

NbTi

8

12

Non-irrad.
1.78x1021 (RT)

Non-irrad.

50

2.65x1021 (RT)

Nb3Sn

16
20
24
Magnetic field (T) Border point

Fig. 2 Change in critical current of NbTi, Nb3Sn and
Nb3Al strands.
lower ILSS and the ILSS does not drop at the dose ofabout 50 MGy at least. However, when the dose increased to about 500 MGy, the ILSS except for the caseof 100 % cyanate ester dropped significantly. In a practical point of view, the pot life is important to handle theresin. The results of the critical current measurements of
NbTi, Nb3Sn and Nb3Al strands are shown in Fig. 2. The
maximum fluence achieved is 2.65 x 1021 n/m2. In case of
the Nb3Sn, the critical current improved by the neutron
irradiation, as far as the test was carried out, especially inthe lower field. Since the magnetization diagram (M-H
curve) was expanded by 1.0 x 1022 n/m2 irradiation, thecritical current would increase more. However, 1.0 x 1024
n/m2 irradiation made the M-H hysteresis shrink and thestrand would not become superconducting at 4.2 K. The
critical temperature of 2.65 x 1021 n/m2 irradiated sample
decreased by 0.2 K. These changes would be caused by
the knock-on effect of the fast neutron.

採択課題番号23043
超伝導マグネット材料の中性子照射効果（核融合研・ヘリカル研究部）西村 新（総研大・数物）阪本光孝

一般通常CO4-12Complex Structure of Ions Coordinated with Hydrophilic Polymer. 12:
Stain Growth on Composite under DC Field

A. Kawaguchi , Y. Gotoh1 and Y. Morimoto
KURRI
Facuty of Text. Sci. and Tech., Shinshu Univ.

1

INTRODUCTION:
We have reported in situ
composite structure through "secondary doping" bydiffusion of m etallic ions into the iodinated hydrophilicpolymers. Polyiodide ions, In- ( n = 3, 5,,), which havebeen doped into the polymers previously, enhances
following diffusion of other molecules or ions at room
temperature.[1,2] As the easiest case for dif fusing
operation of metallic io n, we h ave achieved spontaneous
diffusion of silver ion (Ag+) from AgNO3(aq) intoThis
"iodinated polyamide-6 (PA6, NylonTM-6)".
process can develop precipitation of inorganic salt at
inner space of polymeric matrix and conseque ntly
provides hybrid composite for unlimited shape or size
without plasticizing matrix.[3,4] On the other hand,such spontaneous diffusion can not always advance easily
for some other metallic cations; there is dependence onionic species for both complex structure and diffusion
efficiency.[5]However, in spite of such dependence, ionic diffusion andconductivity in iodinated polymers certainly suggest aview as electrolyte, and we can exp ect possibility ofenforced diffusion of ions driven by applied voltage. Or,
experimental results with SANS data suggest thatswelling can induce resolution of silver iodide (AgI) salt
grain as fillers which precipitated in the composite eventhough AgI is hardly soluble in water.[6] As the first step,
behavior for ionic conduction was investigated with(hybrid)composite"
underapplying"Ag+/In-/PA6
electrical field.
EXPERIMENTS: Commercial filmy products "Rayfan#1401" in thickness of 0.1mm (Toray Film co.ltd.), wasused as non -doped PA6. Af ter annealing at 210 °C in
vacuum, a piece of
PA6 film was immersed into
KI-I2(aq)/0.8N.(iodine-doping) Next, aged in vacuum at
R.T., the iodine-doped PA6 film was i mmersed into
AgNO3(aq)/0.1M.(secondary doping of Ag+) After driedin vacuum again, this filmy sample was clip ped withplatinum plates as conduction probes; both an anode anda cathode were Pt. Applying DC10V, the sample washold in a humid vessel keeping RH 60-85% at R.T.
RESULTS AND DISCUSSION: After secondary dopingof Ag+, the samples showed "light yellow" color similar
as AgI salt.("stage II", Fig.1a)[7] In dried stage, thesample did not indicate explicit conduction current by
DC10V (I < 10-8A), but conduction was o bserved after
the sample hold with the Pt prob es was transferred in thehumid environment; monitored current was fluctuated as
10-6A range, but quantitative discussion has not beenachieved since estim ation of film thickness a nd

uniformity of the sample were not confirmed.
On the other hand, appearance of the sample varied with
applying voltage; "black stain" like expanding branches
grew from the cathode (negative probe) to the anode(positive probe).(Fig.1b-d) Howev er, expansion of thestain did not show any effects for conduction; whilecurrent was observed after transferring in humid
environment, it was ha rdly changed in each stage of
growth of "black stain", before it appeared on the edge ofthe cathode or after it reached the anode. After
experiments, surface area behind the cathode seemed tostand still as ordinary sample while region behind theanode partially turned to black. (Fig.1e)
It is regarded that "black stain" growing from the cathodeto the anode was not reduced Ag(0) since it d id notcontribute to conduction; it m ay be Ag2O or insulative
compounds. Nevertheless, DC conduction and ionictransfer (behind the anode) were induced by support ofswelling process at room temperature. On the other
hand, AgI which is main components of precipitates asfiller in th e hybrid composite is known as i norganic salt
hardly soluble to water and indicating ionic conduction.
Present results complementary to previous SANS
experiments indicate that iodinated polymer can be
regarded as "pseudo solvents" and that ionic diffusion canadvance through polymeric matrix at room temperature.
b

(-)

(+)

(-)

d

a

(+)
(-)

(+)

c
Fig.1. (a) composite after"secondary doping" with Ag +,indicating "stage II"; (b)-(d)development of " black stain"from cathode to anode dur ing
conduction; (e) ionic diffusion(-)
behind released anode.
REFERENCES:[1] A. Kawaguchi, Sens.
Actuators B, 73 (2001) 174-178.
[2] Y. Gotoh, et.al., Polym. Prep. Jpn., 51 (2002), 2259-2259.
[3] A. Kawaguchi, et.al., ibid., 53 (2004), 3372-3372.
[4] A. Kawaguchi, et.al., ibid., 56 (2007), 5471-5472.
[5] A. Kawaguchi, Sens. Actuators B, 63 (2000) 10-17.
[6] A. Kawaguchi, et.al., KURRI Prog.Rep., 2002 (2003), 20-20.
[7] A. Kawaguchi, et.al., Polym. Prep. Jpn., 53 (2004), 3737-3738(+)

e

採択課題番号 23047
親水性高分子－金属塩ナノコンポジットの調製と構造（京大・原子炉）川口昭夫、森本幸生（信州大 ・繊維）後藤康夫

一般通常CO4-13

Variation of Polarization of Coherent Transition Radiation
with Radiator

T. Takahashi
Research Reactor Institute, Kyoto University
INTRODUCTION: For the spectroscopic purpose,
various types of coherent radiation emitted from a
relativistic electron beam have attracted a considerable
attention as a new and powerful light source in theTHz-wave region. Coherent transition radiation (CTR) is
one of such a light source. Whereas synchrotron radiation
has linear polarization along an electron orbit, the electric
vector of transition radiation (TR) emitted from a
metallic screen is axially symmetric with respect to the
trajectory of an electron beam. Therefore, CTR is usually
utilized as a non-polarized light source in the
spectroscopic application. However, circularly polarized
light has been useful in the circular dichroism
spectroscopy. I have proposed a new technique ofgeneration of circularly polarized THz-wave radiation
with wire-grid radiators. [1]. In this report the property ofpolarization with some radiators has been experimentallyinvestigated.
EXPERIMENTAL PROCEDURES: The experiment
was performed at the coherent radiation beamline [2] atthe 40-MeV L-band linac of the Research Reactor
Institute, Kyoto University. The width of the macro pulse
and the repetition rate of the electron beam were 47 ns
and 46 Hz, respectively. The average current of theelectron beam was 1.8 A. The schematic layout of theexperiment is shown in Fig. 1. As a forward radiator (FRin Fig. 1) of forward CTR a wire grid 10 m thick with
25mm spacing was used. A flat aluminum foil 15 m
thick and a wire grid were prepared as backward radiators.
The direction of the wire grid was vertical. The CTR was
detected by a liquid-helium-cooled Si bolometer. In order
to measure the polarization a wire-grid polarizer wasused in front of the detector.
RESULTS: The intensity variation as a function of theazimuth angle of the polarization was observed byrotating the wire-grid polarizer. The observed intensitywith the aluminum-foil backward radiator is shown by
the open squares in Fig. 2. Zero degree corresponds to thevertical component of radiation. The polarization ofobserved radiation was horizontal. On the other hand, thepolarization of radiation from the wire-grid backward
radiator (open circles in Fig. 2) was perpendicular. The

superposition of forward and backward radiation wasobserved in this configuration. Therefore, it was clearly
represented by these results that the horizontal polarizedradiation was emitted by the wire-grid forward radiatorand the backward radiation from the wire-grid backward
radiator had a vertical polarization. The polarization of
backward radiation from an aluminum foil was radially.
This conclusion will lead to the development of thehigh-resolution
time-resolved
circulardichroism
spectroscopy in the THz-wave region.
REFERENCES:[1] T. Takahashi, et al., KURRI-PR 2008 CO4-6.
[2] T. Takahashi et al., Rev. Sci. Instrum. 69 (1998)
3770.
Ti windowFR

AlBRfoilfrom
L-band Linac

electronbeam

M2

Accelerator Room

M1

Shield WallExperimental RoomM4

detector
InterferometerP
M3

Fig.1. The arrangement of the experiment. Keys are:
(FR) a forward radiator, (BR) a backward radiator,(M1, M4) flat mirrors, (M2, M3) spherical mirrors,(P) a polarizer.

Fig.2. Intensity variation of CTR with a wire-grid (opensquares) and an aluminum foil (open circles) as a
backward radiator. The intensity of open circles was
multiplied by ten.

採択課題番号 23051 コヒーレント遷移放射を用いたミリ波領域
高時間分解分光法と円偏光の制御に関する研究（京大・原子炉）高橋俊晴、窪田卓見

共同通常

CO4-14

Release Kinetics of Tritium Generated in Lithium-enriched Li2+xTiO3 by
Thermal Neutron Irradiation

K. Okuno, Y. Oya, M. Kobayashi, J. Osuo, M. Suzuki, A.
Hamada, K. Matsuoka, K. Kawasaki, T. Fujishima, Y.
Miyahara, H. Uchimura, T. Taguchi, K. Toda, R. Miura, T.
Fujii1, and H. Yamana1
Radioscience Research Laboratory, Faculty of Science,
Shizuoka University
1
Research Reactor Institute, Kyoto University
INTRODUCTION: For the development of D-T fusion reactors, it is important to establish an effective fuelrecycling system and a comprehensive model of tritium
migration processes in solid tritium breeding materials. In
the test blanket module for ITER, lithium titanate(Li2TiO3) is a candidate as tritium breeding materials.
Recently, the use of Li2+xTiO3 (x=0.2, 0.4), which is thelithium-enriched Li2TiO3, is proposed to improve thetritium breeding ratio [1,2].
In this study, thermal neutron irradiation was carriedout to evaluate tritium diffusivities in Li2+xTiO3 (x=0, 0.2,
0.4). Therefore, out-of-pile tritium release experiments
under isochronal and isothermal heating were performed.
Comparing to Arrhenius parameters of tritium diffusionin these materials, the effects of excess lithium on tritium
release were also discussed.
EXPERIMENTAL: Powders of Li2+xTiO3 purchasedfrom Kaken Co. were used as samples. The average grain
diameters of Li2.0TiO3, Li2.2TiO3 and Li2.4TiO3 measured
by SEM were 3.0, 1.0 and 1.0 μm, respectively. The samples were introduced into quartz tubes individually andannealed at 1173 K. Thermal neutron irradiations wereconducted at Pneumatic tube 2 (Pn-2) of Research Reactor Institute, Kyoto University (KURRI). The thermal
neutron flux was 5.5 x 1012 n cm-2 s-1. The thermal neutron irradiation was carried out for 10 min, corresponding
to the thermal neutron fluence of 3.3 x 1015 n cm-2.
Out-of-pile tritium release experiments were performedin tritium-TDS (Thermal Desorption Spectroscopy) system at Shizuoka University. TDS spectra obtained inisochronal annealing experiments were simulated by using above-mentioned Arrhenius parameters obtained byisothermal annealing experiments to confirm the adequacy of this work.
RESULTS&DISCUSSION: Figure shows the tritium
TDS spectra for Li2+xTiO3. Major tritium release stages

were located around 600 K for all Li2+xTiO3 samples. In
addition, tritium release around 450 K was clearly foundfor Li2.4TiO3. These tritium release stages around 450 and
600 K were named as Peaks 1 and 2, respectively. The
release rate of Peak 1 at lower temperature side was increased as the amount of excess lithium increased, which
was attributed to the release of tritium trapped in Li4TiO4structure. Peak 2 was considered to a release of tritium
trapped by irradiation defects in Li2TiO3.
Isothermal annealing experiments indicated that tritium
releases were controlled by diffusion process. The diffusion coefficient for Li2.0TiO3 was one order of magnitude
as large as those for Li2.2TiO3 and Li2.4TiO3, although
activation energies for these ceramics were almost thesame to be 0.59 eV. These results showed that activationenergy was determined by the diffusion process of tritiumin Li2TiO3 structure and excess lithium would reduce thediffusion coefficients and activation energies, which wasquite low compared to previous data [3], indicating that it
would be caused by the existence of Li4TiO4 structure.
The simulation of TDS spectra using Arrhenius parameters obtained by isothermal annealing experiments wascompared with the present experimental results It was
found that the rate limiting process of tritium release under He atmosphere was the diffusion process. However,surface reactions are also quite important for actual fusion reactor and further studies using different purge gas
are required for the comprehensive understanding of tritium migration in tritium breeding materials.
REFERENCES:[1] T. Hoshino et al., J. Nucl. Mater., 386 (2009) 1098.
[2] J. Osuo et al., Fusion Eng. Des, 86 (2011) 2362
[3] T. Kinjo et al., Fusion Eng. Des. 83 (2008) 580.

Fig. Tritium-TDS spectra for Li2+xTiO3
with heating rate of 0.5 K / min

採択課題番号23057 核融合炉トリチウム増殖材中トリチウムの移行過程に及ぼす照射効果
共同通常（静岡大・理・放射研）奥野 健二、大矢 恭久、小林 真、押尾 純也、鈴木 優斗、濱田 明公子、
松岡 和志、川崎 淨貴、藤島 徹生、宮原 祐人、内村 大道、田口 僚久、
戸田 健介、三浦 遼（京大・原子炉）山名 元、藤井 俊行、上原 章寛、中野 幸廣