UTTAC-84, 2015

UTTAC
ANNUAL REPORT 2014

TANDEM ACCELERATOR COMPLEX
Research Facility Center for Science and Technology
University of Tsukuba

http://www.tac.tsukuba.ac.jp/

UTTACANNUAL REPORT 2014
April 1, 2014 – March 31, 2015

UTTAC-84, 2015

Executive Editor : Eiji Kita
Editors : Daiichiro Sekiba, Tetsuaki Moriguchi, Kimikazu Sasa,Yoshihiro Yamato
and Aya Kashifuku

UTTAC ANNUAL REPORT is a series of issues, which include annual reports of
Tandem Accelerator Complex, Research Facility Center
for Science and Technology, University of Tsukuba.
Copyright © 2014 by Tandem Accelerator Complex, Research Facility Center
for Science and Technology, University of Tsukuba and individual contributors.
All reports are written on authors’ responsibility and thus the editors are not liable
for the contents of the report.

Tandem Accelerator Complex, Research Facility Center for Science and Technology,
University of Tsukuba
Tennodai 1-1-1, Tsukuba, Ibaraki 305-8577, Japanannual@tac.tsukuba.ac.jp

PREFACE
This annual report covers research conducted at the Tandem Accelerator Complex(TAC),
Research Facility Center for Science and Technology, University of Tsukuba, during fiscal
year(FY) 2014 (April 1, 2014–March 31, 2015). After the Great East Japan Earthquake on
March 11, 2011, research has been limited to that using the 1 MV Tandetron accelerator andradiation source experiments,

57

Co Mössbauer spectroscopy, and positron annihilation

spectroscopy. According to our original plan, we would have finished reconstruction by the endof FY2014, and a new 6 MV accelerator would have started operation. However, since weneeded to finish the removal procedure at first, the reconstruction of the main accelerator was
postponed.

The circumstances of our research has therefore still not changed much from thelast fiscal year. Thus, this volume has slightly fewer pages as compared to older volumes likethe one for last year.
A new 6 MV tandem-type accelerator with support from the government arrived in
mid-March 2014 at the TAC from the National Electrostatics Corporation in Middleton,
Wisconsin, USA. We are hoping for future research activities after the removal of the oldaccelerator.
The efforts of the Open Advanced Facilities Initiative supported by Ministry of Education,
Culture, Sports, Science and Technology (MEXT) were continued in this term. The government
assisted additional facilities related to this program with an extra budget. With this support,
accelerated performance in this program was achieved. We are very much looking forward tooperating and reporting on the new 6 MV accelerator.
Editors-i-CONTENTS

1. ACCELERATOR AND RELATED FACILITIES
1.1 Accelerator operation 2014 ···········································································

1

1.2 Performance prediction of the new Tsukuba AMS system········································

4

1.3 Reconstruction of the Lamb-shift polarized ion source············································

6

2. NUCLEAR PHYSICS
2.1 Measurements of nuclear moments for unstable nuclei at RCNP································

8

2.2 Beam irradiation test of Havar foil and Pt target for KISS experiment ·························

10

2.3 Production of unstable nuclei via resonant proton-capture reactions ···························

12

3. ACCELERATOR MASS SPECTROMETRY
3.1 Performance test of automated sample preparation system for 14C-AMS using IAEA
reference materials ····················································································· 13
3.2 Study on the migration behavior of Fukushima accident-derived iodine-129 from land area
to the marine environment ············································································
3.3 Changes in 129I / 127I ratio of crater lake and volcanic activity at Zao volcano ·················

15

3.4 Technological development for Strontium-90 determination using AMS ······················

19

17

3.5 Successive searches of iodine-129 contamination in the chemical sample preparation
rooms for AMS·························································································· 20

4. MATERIALS ANALYSIS BY ION BEAMS OR RADIO ISOTOPES
4.1 Micro-PIXE analyses of single fluid inclusions in quartz from Tanzawa granite, Japan······

23

4.2 Coincidence detection system of ion and secondary electron in HERDA ······················

26

4.3 Straggling effect in channeling on Si(100) with metal thin films ································

28

4.4 Mössbauer spectroscopy of ferromagnetic Fe3O4 nanoparticles developed for magnetic
hyperthermia ····························································································

30

4.5 Conversion electron Mössbauer spectroscopy (CEMS) of cobalt ferrite thin films···········

32

4.6 Magnetization control of Co ferrite thin films by Kr ion implantation·························

34

4.7 Oxygen and sulfur isotopic analysis of ion-induced sulfate production reaction initiatedvia proton beam·························································································- iii -

36

5. LIST OF PUBLICATIONS
5.1 Journals ··································································································

38

5.2 International conferences··············································································

42

6. THESES ·······································································································

45

7. SYMPOSIA
The 15th Japanese national workshop on surface and interface ion beam analysis····················

46

The 17th Japanese Symposium on Accelerator Mass Spectrometry······································

51

8. LIST OF PERSONNEL···················································································

55- iv -

1.
ACCELERATOR AND FACILITIES1.1

Accelerator operation 2014

K. Sasa, S. Ishii, H. Kimura, H. Oshima, Y. Tajima, T. Takahashi, Y. Yamato,
D. Sekiba, T. Moriguchi, E. Kita
The University of Tsukuba Tandem Accelerator Complex (UTTAC) is a major center of ion beam
research in Japan. We have operated and maintained the 1 MV Tandetron accelerator, the 1 MV
high-resolution Rutherford back scattering (RBS) system and the radio-isotope utilization equipment. At
present, the 6 MV Pelletron tandem accelerator system has been designed and constructed at the university
as part of the post-quake reconstruction project.
The total service time of the UTTAC multi-tandem accelerator facility was 2,512 hours in the fiscal
year 2014. 816 hours for accelerators and 54 days for the radio-isotope utilization equipment were used
under the project "Promotion of Advanced R&D Facility Utilization", which was supported financially by
the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of JAPAN. In the project, a
total of 17 research programs were conducted in 2014.
1 MV Tandetron accelerator
The operating time and the experimental beam time of the 1 MV Tandetron accelerator were 671.4
and 228.1 hours, respectively, during the total service time in 2014. A total of 50 research programs werecarried out and a total of 499 researchers used the 1 MV Tandetron accelerator. Figure 1 shows thepercentage of accelerated ions for the 1 MV Tandetron accelerator. Figure 2 shows the percentage of
research fields for the 1 MV Tandetron accelerator in 2014.

Fig. 1. Percentage of accelerated ions for the

Fig. 2. Percentage of research fields for

1 MV Tandetron accelerator in 2014.

the 1 MV Tandetron accelerator in 2014.

6 MV Pelletron tandem accelerator
We planned to install the new horizontal-type 6 MV Pelletron tandem accelerator in the experimentalroom on the first floor to replace the damaged 12UD Pelletron tandem accelerator by the Great East Japan
Earthquake of 11 March 2011 [1]. A three-year plan for the new accelerator’s construction was started in2012. The 6 MV Pelletron tandem accelerator will be used for various ion-beam research projects, such as

1

AMS, microbeam applications, particle-induced X-ray emission (PIXE) analysis for geoscience andmaterials research, heavy ion RBS and elastic recoil detection analysis, nuclear reaction analysis forhydrogen in materials, and high-energy ion irradiation for semiconductor and nuclear physics. All
experimental equipment is installed on the first floor at UTTAC. Only rooms for control and data analysis
are on the second floor. Figure 3 gives an overview of the equipment on the first floor. The newaccelerator system consists of the 6 MV Pelletron tandem accelerator, four new ion sources, theLamb-shift polarized ion source (S1 in Fig. 3), and five new beam courses. After the 105° analyzer magnet,
the beam line is separated in two directions by the 40° switching magnet in the accelerator room. A
high-energy beam transport line equipped with a vertical ion-irradiation system is connected from theaccelerator room to the existing experimental room, which houses seven beam courses. A total of 12 beamcourses will be available for nuclear physics, ion beam applications, and AMS.
The Lamb-shift polarized ion source was used as the injector of polarized proton and deuteron beams to
the old tandem accelerator on the 9th floor at UTTAC [2]. After the earthquake, this ion source was moved
to a new experimental building outside the accelerator building. In the accelerator room, there are four
negative-ion sources. In Fig. 3, S2 is a high-current Cs-sputtering negative-ion source (SNICS II), and S3
is a radio frequency charge exchange ion source (Alphatros) to produce He− beams for injection into the 6
MV Pelletron tandem accelerator. S4 and S5 are the multi-cathode Cs-sputtering negative-ion sources(MC-SNICSs) for AMS.
In the accelerator room, the ion beam analysis (IBA) system equipped with a high-precision five-axis
goniometer is located on the L1 beam course. The L2 beam course has a large environmental testing
chamber (1 m diameter) that will be mainly used for the radiation-tolerance testing of semiconductor
devices for space satellites. The L3 beam course is constructed as follows: the Oxford microbeams
quadrupole lens system [3] is used to obtain spot diameters of the order of 1 μm and below, and asuperconducting detector [4] is used for high-sensitivity PIXE analysis. The L4 beam course is therare-particle detection system for AMS. The L5 beam course is a general-purpose line for ion beam
applications. In the experimental room, there are two large magnetic spectrographs (A6 and A7 beamcourses) for nuclear physics. Other beam lines are used for ion beam channeling (A2 beam course), 3D
fabrications with swift heavy ions (A3 beam course), and hydrogen analysis (A4 beam course). There isalso a large general-purpose chamber (A5 beam course).
The 6 MV Pelletron tandem accelerator was installed in the spring of 2014 at the University of Tsukuba.
Routine beam delivery and experiments will start in 2015.
References[1] K. Sasa, Proceedings of HIAT 2012, Joint Accelerator Conferences Website (2012) 80–82.
[2] Y. Tagishi, J. Sanada, Nucl. Instr. Meth 164 (1979) 411–413.
[3] G. W. Grime, F. Watt, Nucl. Instr. Meth B 30 (1988) 227–234.
[4] M. Ohkubo, S. Shiki, M. Ukibe, N. Matsubayashi, Y. Kitajima, S. Nagamachi, Scientific Reports 2(2012) article number:831.

2

Fig. 3. Overall view of the first floor at UTTAC. The 6 MV Pelletron tandem accelerator and its beamlines, the 1 MV Tandetron accelerator, and a positron-annihilation spectrometry system are set up on thefirst floor.

Fig. 4. Photograph of the 6 MV Pelletron tandem accelerator under construction in the accelerator room.

3

2.
NUCLEAR PHYSICS

1.2

Performance prediction of the new Tsukuba AMS system

K. Sasa, T. Takahashi, M. Matsumura, T. Matsunaka, Y. Satou, D. Izumi, K. Sueki
Fig. 1 details the Tsukuba 6 MV AMS system [1]. It has two Cs sputtering negative ion sources for
AMS: a 40-sample MC-SNICS for the routine measurement of all nuclides and a hybrid source with a
39-sample MC-SNICS equipped with a CO2 gas introduction system [2] manufactured by NEC with either
graphite or CO2 samples. It is expected to achieve ultra-small-scale 14C AMS measurements of 10 μg C. At
the low-energy side, the injection energy from the ion sources is 65 keV. The 90° high-mass-resolution
double-focusing magnetic analyzer with a 457 mm radius has a mass energy product of ME/Z2 = 15 amu
MeV. A 15 kV pulsed power supply is provided to bias the 90° magnetic analyzer chamber for thesequential injection of up to four different beams with a maximum mass difference of 17%. The main
accelerator (model 18SDH-2 Pelletron, NEC) has a long gas stripper tube assembly and a foil changer
with 80 foil holders for equilibrium stripping ions. Carbon stripper foils will be mainly used for 36Cl AMS
to obtain chlorine ions in a high charge state. The stripper gas canal is about 10 mm in diameter and 95 cm
long. The rare-particle detection system is set on the −20° port on the switching magnet. A 22.5° ESA(3.81 m radius) is provided to filter out unwanted ions whose mass energy product (ME/Z2) is the same as
the rare isotope of interest. Only ions with the correct energy-to-charge-state ratios (E/Z) will pass throughthe ESA, which has a resolution of E/ΔE = 200. A five-electrode gas ionization detector is installed on theend station of the rare-particle detection system, which is similar in design to the gas ionization detector
on the AMS system of the SUERC [3].
55°bending
magnetHE:
ME/Z2 = 176 amu MeV

90°analyzer
magnetR = 1.27 m−20°
Gas ionization detector(5 anodes type)22.5°ESA
R = 3.81 m

Three 90° rotational
Electrostatics Spherical
Analyzers (ESAs)

TripletQ-magnet

SwitchingmagnetRare-particle detection line

SNICS

CO2 gas type
MC-SNICS

Alphatros

MC-SNICS

40°switchingmagnetSF6 gashandling system

AMS injection

Offset-FCs Beamattenuator

LE:
ME/Z2 = 15 amu MeV

TripletQ-magnet

5m

Offset-FCs

TripletQ-magnet

Einzel lens
90°sequential
injection magnet

TripletQ-magnet

2nd stripper foil
Terminal with gas and foil stripper

6 MV Pelletron tandem accelerator

Electrostatics-Q

105°analyzer
magnetR = 1.27 m

Fig. 1. Details of the Tsukuba 6 MV AMS system.
The Tsukuba 6 MV AMS system is expected to measure all standard AMS species routinely. We
simulated AMS performance by using the Particle and Heavy Ion Transport Code System (PHITS) [4]. Fig.

4

2 shows sample two-dimensional spectra of 36Cl in the gas ionization detector simulated by PHITS. The
simulation showed that 36Cl7+ with an energy of 46.8 MeV is injected into the gas ionization detector. If
the entrance window of the gas ionization detector is 150-nm-thick Si3N4 foil, the optimal propane gaspressure is estimated to be 42 Torr. The simulation uses 36Cl : 36S = 10,000 : 10,000,000 as the incident
particles in the gas ionization detector. The 36Cl was clearly separated from the 36S in the gas ionization
detector by the Tsukuba 6 MV AMS system. Table 1 lists the AMS performance of the 6 MV Tsukuba
system estimated from PHITS simulations and primary beam tests. The new system will start routine
multi-nuclide AMS measurements of 10Be, 14C, 26Al, 36Cl, 41Ca, and 129I in 2015.
Deposited Energy in Plate 5 : ΔERes [MeV]

36Cl7+: 46.8 MeV (1.3 MeV/u)

36S

36Cl

Deposited Energy in Plate 1: ΔE1 [MeV]Fig. 2. Two-dimensional spectra of 36Cl AMS in the rare-particle detection system simulated by the PHITS.
Partial energy loss in the first anode along the ion path is indicated on the horizontal axis (ΔE1), and a total
residual energy signal from the fifth electrode, a cathode, is shown on the vertical axis (ΔERes).
Table 1 AMS performance estimated from PHITS simulations and primary beam tests.
Isotopes
TargetInjected ion
Injectable ion current(μA)
Detected ion/stripper
Terminal voltage (MV)
Transmission (%)
Background
Precision (%)

10

14

26

36

41

129

Be
BeO
BeO−

C
Graphite
C−

Al
Al2O3
Al−

Cl
AgCl
Cl−

Ca
CaF2
CaF3−

l
AgI
I−

4

50

1

30

0.3

20

10

Be3+
(Gas)
4.5
20
2 × 10−15
3

14

C4+
(Gas)
4.5
55
5 × 10−16
0.3

26

Al3+
(Gas)
4.3
20
5 × 10−15
3

36

Cl7+
(Foil)
6
20
1 × 10−15
3

41

Ca5+
(Gas)
5
5
3 × 10−143References[1] K. Sasa et al., Nucl. Instr. Meth. B (2015) in press. doi:10.1016/j.nimb.2015.04.028.
[2] S. Xu et al., Radiocarbon 46 (2004) 59–64.
[3] C. Maden et al., Nucl. Instr. Meth. B 259 (2007) 131–139.
[4] T. Sato et al., J. Nucl. Sci. Technol. 50 (2013) 913–923.

5

129 4+

I
(Gas)
3.5
8
1 × 10−1431.3

Reconstruction of the Lamb-shift polarized ion source

T. Moriguchi, Y. Yamato, Y. Tagishi, T. Takahashi, S. Ishii, Y. Tajima, D. Sekiba, A. Ozawa
A polarized ion beam is an effective tool for measuring physical quantities such as analyzing power
and nuclear magnetic moment. The Lamb-shift polarized ion source (PIS) was installed at UTTAC in 1976
for experimental nuclear physics [1]. The PIS of this type makes it possible to produce highly polarized
negative proton and deuteron beams. The PIS, which was located at the 9th floor of the main building, wasused as one of the ion sources for the 12UD Pelletron tandem accelerator. However, the PIS was damaged
seriously by the Great East Japan Earthquake on 11 March 2011. A part of the damage of the PIS isreported in Ref. [2].
After the disaster, the reconstruction of the PIS was decided to use as the ion source for the newly
designed 6 MV tandem accelerator. The new building for the PIS was constructed at the west-side of theaccelerator room [3]. Since main components of the PIS such as a duoplasmatron chamber, a spin filter, anargon gas cell, an electrostatic steerer and a Wien filter were reusable, they were moved from the 9th floorof the main building to the new one, and then were reconstructed. Other components and parts of the PIS
except for the reusable ones were basically replaced to new ones. Until March 2015, almost all of thereconstruction of the PIS has been completed, as shown in Fig. 1. Fig. 2 shows the present layout of the
PIS. New scroll pumps and turbo molecular pumps (magnetic floating type) are used as the present
vacuum system. With this vacuum system, the beam line of the PIS is maintained at a vacuum of ~ 10-8
Torr. Acceleration tubes, quadrupole magnets and some beam ducts were newly produced and were
installed as the beam transport line of the PIS. Gate valves broken by the earthquake were overhauled forreusing. Many new power supplies for operating the PIS are placed on the high voltage insulation stage.
This stage was designed originally for the PIS. Most devices on this stage are controlled through opticalfibers. For instance, the FAst Spin State Interchange Control System (FASSICS), which was designed
newly, is connected to the PIS through optical fibers. This device makes it possible not only to switch aspin state, but also to decide whether or not a beam is polarized. As shown in Fig. 2, a beam produced by
the PIS is bent 90° by an electrostatic analyzer (ESA) and transported to the accelerator room throughoutside of the building.

Fig. 1. Pictures of the PIS after the reconstruction.

6

Fig. 2. Present layout of the PIS. The PIS is mainly composed of a duoplasmatron (DP), a spin filter(SF), an argon gas cell (Ar), an electrostatic steerer (ESS) and a Wien filter (WF). A beam produced by
the PIS is transported to the accelerator room (the right-hand side) through outside of the building.
We are presently preparing the control system using EPICS for the PIS. After that, we will perform
beam tests (intensity, polarization, transmission and so on), and then measure magnetic moment of
unstable nuclei with a polarized beam produced by the PIS.
References[1] Y. Tagishi et al., UTTAC Annual Report 1976 (1977) 12.
[2] K. Sasa et al., UTTAC Annual Report 2010 (2011) 1.
[3] K. Sasa et al., UTTAC Annual Report 2012 (2013) 3.

7

2.1

Measurements of nuclear moments for unstable nuclei at RCNP

Y. Ishibashi, D. Nagae, Y. Abe, Y. Ichikawa, T. Moriguchi, A. Ozawa, K. Sawahata, H. Ueno1
The β -ray detected nuclear magnetic resonance (β -NMR) method [1] is an efficient method to measure
the nuclear magnetic (µ ) moment of unstable nuclei. The absolute values of µ moments are measured
for various nuclei by β -NMR. However, the signs of µ moments are rarely measured experimentally.
Therefore, to determine the sign of µ moment, applying a rotating RF is necessary. The rotating RF
system has been developped [2,3] to determine the sign of µ moment by β -NMR. In the past, the rotating
magnetic field was obtained using two Helmholtz-like coils with axes crossed at right angles, and theexperimental apparatus is shown in Reference [3]. In the present work, the rotating magnetic field wascontrolled by changing the internal phase of a function generator (see Fig. 1) without cable delay. Thereby,
without changing the resonance condition of the tank circuit, it was possible to change the phase.
Tank circuit (90 deg.)ch1᳸Variable
capacitor

Attenuator

F.G.
ch2

Amp

Ferrite core

Tank circuit (0 deg.)

RF2

RF1

Magnet pole
β-ray counter
telescope
Spin polarized
beam

Staticmagnetic field

CaF2 stopper
Staticmagneticfield

Spin polarizedbeam

RF coilFig. 1. Block diagram of the RF system for rotating magnetic field and a schematic layout of the β -NMR
setup.

In this work, a performance of the system was studied with spin-polarized 20 F (I π = 2+ , T1/2 = 11.163s, µ (20 F) = +2.09335(9) µN ) nuclei at the Research Center for Nuclear Physics, Osaka University. A spin→−polarized 20 F was produced in the 19 F( d , p)20 F reaction. In this reaction the polarization of the beam→−
particles is transferred to each nucleus. The d beam was produced by a polarized ion source [4], andwas accelerated up to E/A = 5 MeV by the AVF cyclotron. The polarized beam was impinged on a CaF2
crystal (12 mm × 12 mm × 1 mmt ) to produce the polarized 20 F. The crystal was placed at the center ofthe β -NMR apparatus, at room temperature with a static magnetic field B0 = 350 mT applied.
The β -rays emitted from 20 F nuclei were detected with three plastic scintillator telescopes locatedabove and below the crystal. The up/down ratio R of the β -ray counts is written as R0 ≈ a(1 + Aβ P)/(1 −Aβ P), where a denotes a constant factor representing asymmetries in the counter solid angles and efficien1 RIKEN Nishina Center8

cies, Aβ and P denote the β -ray asymmetry parameter and the degree of spin-polarization. A rotating RF
perpendicular to the B0 is applied to 20 F by using the two pairs of coils. If the frequency and the direction of the rotating RF correspond to the resonant one, the direction of the spin-polarization is inverted(P → −P) by the NMR. Thus, the up/down ratio is changed as R ≈ a(1 − Aβ P)/(1 + Aβ P). When thepolarization is altered due to the resonant spin change, a change appears in the ratio R0 /R. The β -ray√√asymmetry Aβ P is written by, Aβ P = ( (R0 /R) − 1)/( (R0 /R) + 1).
Typical time spectrum for the β -rays is shown in Fig. 2. The obtained purity of 20 F was nearly 100%.
In this experiment, we firstly measured µ moment by β -NMR applying the linear RF using tank circuit(0 deg.). Then, we measured the µ moment using a tank circuit (90 deg). The obtained µ moments wereconsistent with reported values [5]. Finally, we tried to measure the sign of µ (20 F), applying rotating RF.
Analysis of the results is in progress.

Count [ / 8 s ]105

20F(T1/2) = 11.103 s

104
41Sc(T1/2) = 596.3 ms

0

5

10

15

20

25
30
Time [ s ]35Fig. 2. Typical time spectrum of 20 F.

References[1] K. Sugimoto, et al., J. Phys. Soc. Jpn. 21 (1966) 213.
[2] T. Niwa et al., UTTAC 81 (2012) 5.
[3] D. Nagae et al., Hype. Int., 220 (2013) 65.
[4] K. Hatanaka et al., Nucl. Instr. Meth., 217 (1983) 397.
[5] N.J. Stone, At. Data Nucl. Data Tables 90 (2005) 75.

9

40

45

2.2

Beam irradiation test of Havar foil and Pt target for KISS experiment

M. Mukai, Y. Hirayama1, N. Ishiyama1, S.C. Jeong1, H. Miyatake1, M. Oyaizu1, Y.X. Watanabe1, A.
Ozawa
KEK RNB group has developed KEK Isotope Separation System (KISS) [1] to measure theneutron-rich short-lived nuclei related to the astronucleosynthesis. In the KISS project, the gas cell filledwith argon gas of 50 kPa is used to stop the target like fragments produced by multi-nucleon transfer
reaction of 198Pt target (6 mg/cm2 in thickness) and 136Xe19+ beam (E/A = 10.75 MeV, beam size 10 mm indiameter). Extraction efficiency of KISS has achieved about 0.15% with 124Xe beam of 10 pnA so far. To
perform the lifetime measurement of 200W with such extraction efficiency, the beam of 100 pnA is required.
Such a high beam current may damage the Havar foil (gas cell window) and the 198Pt target. We need to
study the limitation of beam intensity as the foils are not broken. We performed beam irradiation test of
the Havar foil (3.6 μm in thickness) and the platinum target (1.2 μm in thickness) using 1H+ beam of 1.92
MeV from 1 MV tandetron. Beam current was from 20 pnA to 2 pμA and beam spot size was 2 mm indiameter. Energy losses [W/m2] of the proton beam in the tested Havar and platinum foils correspond to
those of the 136Xe19+ beam intensities of from 1 pnA to 100 pnA in the Havar foil (3.6 μm in thickness) andfrom 0.49 pnA to 49 pnA in the 198Pt target (6 mg/cm2 in thickness).
Experiment was performed using the C-course chamber. To monitor the change of the target
thickness, energy of back scattered proton was measured using SSD. SSD was masked with an aperture of
1 mm in diameter and placed at 15 cm away from thetarget surface and at the angle of about 160 degreefrom the beam axis. Temperature of target wasmeasured using a radiation thermometer.
Beam irradiation time was one hour withmaximum beam current of 1.9 pμA and 2 pμA for theHavar foil and the platinum foil, respectively. Width ofthe energy distribution of the back scattered proton(Fig. 1) was not changed during the experiment in bothtargets. It means that target thickness of both targets
was not changed. Red gleam from the target surface

Fig. 1. Measured energy distribution of thewas observed when the proton beam with the current ofback scattered proton from the Havar foil

higher than 1 pμA was irradiated to both targets. Target

with beam current of 1.9 pμA. Energy

temperature of 1223 K in the Havar foil and less thandistribution below 1300 keV originated from973 K in the platinum target were measured withthe back scattered protons around a beammaximum beam current. In the Havar foil, a burn markduct downstream of the target and a beam

was observed over the beam spot. However, thesecollimator upstream the target.

1

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801,
Japan

10

measured temperatures are several hundred kelvin lower than the melting points of both materials. It
implies that Xe beam with 100 pnA can be available at the KISS on-line experiment.
References[1] S.C. Jeong et al., KEK Report 2010-2(2010).

11

2.3

Production of unstable nuclei via resonant proton-capture reactions

A. Ozawa, Y. Ichikawa, T. Moriguchi, K. Sawahata
The proton-capture reactions have been investigated for long time for various stable nuclei and by thevarious energy range. The motivations for the investigation are based on astrophysical interests and searchfor excited states of produced nuclei. Among the proton-capture reactions, resonant proton-capture
reactions are very interesting since the reaction rate is very large and the reaction occurs even in low
energy (Ep < 500 keV). Since the energy widths of resonant proton-capture reactions are very narrow, they
are also applied to calibrate ‘absolute’ acceleration energy in accelerators. In the point of production of
unstable nuclei, the resonant proton-capture reactions are attractive. In the UTTAC, there is Lamb-shift
type polarized ion source, where polarized proton beams are available. If the polarized proton beams arecaptured, reaction products will be highly polarized. If the products are unstable nuclei, we may obtainhighly polarized unstable nuclei. If we obtain the polarized unstable nuclei, we may be able to measure
nuclear moments for these nuclei by using β-NMR method.
Among the resonant proton-capture reactions, specially, following reactions are interesting:24

Mg(p,γ)25Al(I=5/2+, T1/2=7.1 s) Ep=419 keV Eγ=2.674 MeV

29

Si(p,γ)30P(I=1+, T1/2=150 s) Ep=417 keV Eγ=5.9 MeV

40

Ca(p,γ)41Sc(I=7/2+, T1/2=0.6 s) Ep=1842 keV Eγ=2.883 MeV

58

Ni(p,γ)59Cu(I=3/2-, T1/2=82 s) Ep=1424 keV Eγ=4.82/4.33 MeV

In this list, typical proton-energies for each resonant proton-capture reactions and typical γ-ray energies tobe observed in the reactions with the respective proton energies are also shown. All reaction products in
the reactions are short-lived unstable nuclei. In the point of nuclear moment measurements, the magnetic
moment of 30P is not known. The magnetic moment of 59Cu has a large error bar. The quadrupole momentsof 25Al, 30P and 59Cu are not known. Thus, if we obtain large production yields for these nuclei by theresonant proton-capture reactions, investigation of the moments for these nuclei may be possible.
We performed a preliminary experiment to produce 25Al and 30P by the resonant proton-capture
reactions in UTTAC. The resonant proton-capture reactions for 25Al and 30P are well investigated [1, 2].
Purposes of the preliminary experiment were to check effective yields and contaminants. We used proton
beams with Ep=500 keV accelerated in 1 MV tandem accelerator. We used MgF2 and MgO target for 25Al
production, and Si and SiO2 targets for 30P production. Thickness of the targets was 0.5 mm. A typical
proton-beam intensity was 10 nA. γ-rays from reaction products were measured by a HP-Ge detector.
Finally, we irradiated for about 3000 seconds to MgO and Si targets, however we did not observe
prominent γ-ray peaks related to 25Al and 30P. We will suppress background events and increase beam
intensity in the further measurements and also we will try the production of 41Sc and 59Cu.
References[1] D.C. Powell et al., Nucl. Phys. A 660 (1999) 349 and references therein.
[2] J.P.L. Reinecke et al., Nucl. Phys. A 435 (1985) 333 and references therein.

12

3.
ACCELERATOR MASS SPECTROMETRY

3.1

Performance test of automated sample preparation system for
C-AMS using IAEA reference materials

14

T. Matsunaka, K. Sasa, K. Sueki, T. Takahashi, M. Matsumura, H. Matsuzaki1, T. Nakamura2
New 14C-AMS system using automated sample preparation system with an elemental analyzer (EA)and CO2 gas ion source was installed at the University of Tsukuba Tandem Accelerator Complex(UTTAC). Technical innovation of 14C-AMS system is expected in terms of speed-up, high repeatability,
low background, and microscale radiocarbon analysis. Firstly, we tested the ability of the sample
preparation system using reference materials, which shows known 14C activities from 0 to 150 pMC(percent Modern Carbon), purchased from International Atomic Energy Agency (IAEA) and National
Institute of Standards and Technology (NIST).

Fig. 1. (A) Conceptual diagram of 14C-AMS system using automated sample preparation system. (B)Photograph of automated class vacuum line coupled with an EA. (C) Chromatogram of N2, CO2, andSO2 separated by the EA.
Graphite materials were prepared using the automated sample preparation system with 20-reactor
graphite lines (Fig. 1) from IAEA-C1 (Marble), C2 (Travertine), C3 (Cellulose), C4 (Wood), C5 (Wood),
C6 (Sucrose), C7 (Oxalic acid), C8 (Oxalic acid), C9 (Wood), and NIST-4990C (Oxalic acid). Threecarbon isotopes of 12C, 13C, and 14C were measured for the graphite with AMS system at Nagoya
University and the University of Tokyo. Fig. 2 shows an excellent linear relationship between the wide
range of measured and consensus 14C values (pMC) for the reference materials. These measured values arein good agreement with the consensus values. The 14C activities of IAEA-C1 graphite were 0.04 – 0.1
pMC which corresponds to 55,000 – 64,200 yr BP (before present) at late three times, relatively lower
than the background level of 0.1 – 0.2 pMC in common laboratories (Fig. 3). Therefore, the automatedsystem is available for 14C dating of old sample until 55,000 yr BP.
1
2

The University Museum, The University of Tokyo
Center for Chronological Research, Nagoya University

13

Fig. 2. The correlation between consensus and measured 14C activities of reference materials purchasedfrom IAEA and NIST. The regression line and correlation coefficient (R2) are shown in the correlation
diagram.

Fig. 3. 14C activities of IAEA-C1 graphite prepared with automated sample preparation system at the
University of Tsukuba. Back ground levels of the system are shown from 14C activities and calculated
14

C ages of IAEA-C1.

14

3.2

Study on the migration behavior of Fukushima accident-derived
iodine-129 from land area to the marine environment

T. Matsunaka, K. Sasa, K. Sueki, Y. Onda1, T. Ishimaru2, K. Taniguchi1,3, Y. Wakiyama1,4, M. Honda,
T. Takahashi, M. Matsumura, H. Matsuzaki5
The March 2011 accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) in Japan results inthe massive release of high volatility fission products, including 129I (8.1 GBq [1]) and 131I (120–160 PBq,
[2–3]). The long-lived 129I (T1/2 = 15.7 million years) is one of the important radionuclides, which we needto evaluate its migration behavior from Japan’s land area to the marine environment because of its
relatively high chemical reactivity, biological concentration in the marine ecosystem, and affinity for the
thyroid gland although it is less radiologically harmful than the short-lived 131I (T1/2 = 8.02 days). The
present study aimed to evaluate the following three points: 1) the source and the discharge of particulate
129

I in the Niida River, 2) 129I distribution in the marine sediment around estuary of the Niida River system,and 3) 129I distribution in the sea water and the marine organism in area close to the FDNPP.
In the Niida River system where the upstream are in the relatively high-contaminated area located
30–40 km northwest from the FDNPP, total suspended solid (SS) each month from December 2012 toJanuary 2014 were continuously collected at Haramachi site (5.5 km upstream from the river mouth) of
the downstream river by installing the time-integrative SS sampler. Marin surface sediments (0–3 cm
depth) were collected at the two sites within 2 km from mouth of the Niida River. On the other hand, sea
water samples of 2 L in water depths of 0 m, 5 m, 10 m, 15 m, and 20 m, and rock fish were collected at asite 6 km south-southeast of the FDNPP in July 2014. The iodine in SS, sediment, and rock fish of 0.2–0.5
g was volatilized and trapped in an organic alkaline solution (~10 ml) by pyrohydrolysis method [4]. Afteradding 2 mg iodine carrier to the trap solution and the filtered water sample of 1 L, the iodine was isolated
and precipitated as AgI. The 129I/127I ratio of AgI targets were measured using an AMS system at the Micro
Analysis Laboratory Tandem accelerator (MALT), The University of Tokyo (Matsuzaki et al., 2007). 127I
in the trap solution and the water sample were measured by an ICP-MS at the University of Tsukuba. The
original 129I activities and 129I/127I ratios in the samples were calculated using 127I concentration obtained
from ICP-MS and 129I/127I ratio obtained from AMS.
129

I activities and 129I/127I ratios in SS of the Niida River were 0.9–4.1 mBq kg−1 and (2.5–4.4)×10−8,which were strongly correlated with the total dry weight of monthly SS samples with correlation
coefficient (R2) of over 0.79. 129I activities and 129I/127I ratios in SS were considered to infer the source ofSS (relatively high-level contaminated upstream area or low-level contaminated downstream area).
Meanwhile, the discharged particulate 129I at Haramachi site were estimated to be 7.7–12 kBq month−1from September to October 2013. Therefore, relatively massive amount of particulate 129I from the1

Center for Research in Isotope and Environmental Dynamics, University of Tsukuba
Oceanographic Observation Center, Tokyo University of Marine Science and Technology
3
Prefectural centre for Environmental Creation, Fukushima Prefectural Government
4
Institute of Environmental Radioactivity, Fukushima University
5
The University Museum, The University of Tokyo2

15

upstream were transported to the downstream of the Niida River from September to October 2013. 129I
activities in the surface marine sediments from two sites within 2 km from mouth of the Niida River were
5.8–8.4 μBq kg−1, 2–3 orders of magnitude lower than that of SS at Haramachi site of the Niida River.
The 129I activity in surface sea water collected 40 months after the accident was 2.2 μBq L−1 (Fig. 1), ~2
times larger than the previous 129I data in surface sea water collected 3 months after the accident [1]. 129I
activities in the rock fish were 42–48 μBq kg−1, approximately 20–400 times larger than that of sea waterof same site. There is a possibility of biological 129I concentration in the rock fish. Further investigations
are needed to evaluate the mechanism.

Fig. 1. Profiles of 127I concentration, 129I activity, and 129I/127I ratio in sea water (white squares) and rockfish (black squares) collected at a site 6 km south-southeast of the FDNPP.
References[1] X.L. Hou, P.P. Povinec, L.Y. Zhang, K. Shi, D. Bidduiph, C.C. Chang, Y. Fan, R. Golser, Y. Hou,
M. Jeskovsky, A.J.T. Hull, Q. Liu, M. Lou, P. Steier, W. Zhou, Environ. Sci. Technol. 47 (2013)
3091–3098.
[2] M. Chino, H. Nakayama, H. Nagai, H. Terada, G. Katata, H. Yamazawa, J. Nucl. Sci. Technol. 48(2011) 1129–1134.
[3] H. Terada, G. Katata, M. Chino, H. Naga, J. Environ, Radioact. 112 (2012) 141–154.
[4] Y. Muramatsu, Y. Takada, H. Matsuzaki, S. Yoshida, Quat. Geochro. 3 (2008) 291–297.
[5] H. Matsuzaki, Y. Muramatsu, K. Kato, M. Yasumoto, C. Nakano, Nucl. Instr. Meth. B 259 (2007)
721–726.

16

Changes in 129I/127I ratio of crater lake and volcanic activity at Zao
volcano3.3

T. Matsunaka, K. Sasa, K. Sueki, T. Takahashi, M. Matsumura, A. Goto1, T. Watanabe2, N. Tsuchiya2,
N. Hirano2 , H. Matsuzaki3
The volcanic activity has become higher at Zao volcano in Miyagi and Yamagata Prefectures, Japan,
since January 2013 after the 2011 Tohoku Earthquake [1]. Up to 106 times of the monthly volcanic
earthquakes were observed in August 2014, and twice of the white turbidity were found in the surface of
crater lake in October 2014. Basic water quality of crater lake have been studied by Tohoku University
since the water quality of crater lake are correlating with volcanic activity. As a part of this investigation,
we are trying to monitor the volcanic activity using 129I/127I ratios at Zao volcano.
Long-lived 129I (T1/2 = 15.7 million years) is produced in nature by cosmic-ray-induced spallation of
xenon in the atmosphere and spontaneous fission of uranium in the lithosphere [2]. Values of 129I/127I ratios
found nowadays in different environments are 2–8 orders of magnitude larger than that in the pre-nuclear
era (1.5×10–12, [3]) by the release of anthropogenic 129I originating from spent nuclear fuel reprocessing,nuclear weapons testing, and nuclear accident [2]. 129I/127I ratio in precipitation at Fukushima area rose to~10–5 soon after the nuclear accident [4]. In our previous study, 129I/127I ratio in lake water collected in
October 2013 from the crater lake at Zao volcano were 2.2×10−9, which were affected by anthropogenic
129

I. In terms of the global iodine cycle, chronologically-old iodine with low isotopic ratio was considered

to be supplied into the crater lake from underground corresponding to the volcanic activity, resulting thedecrease in 129I/127I ratio of the crater lake. The present study aimed to elucidate distribution of 129I/127I
ratio and source of iodine in the crater lake, and the relativity between 129I/127I ratio in the crater lake andvolcanic earthquake for the monitoring of volcanic activity at Zao volcano using 129I/127I ratio.
Water samples (2 L) were collected 6 times from the surface of crater lake in eastern side of Zao
volcano from October 2013 to October 2014 including before and after the white turbidity phenomena. In
May 2014, water samples were also collected from the central lake in water depths of 0 m, 6 m, 12 m, and
18 m at the site of ~20 m water depth, snow ice around the lake, and Zao hot spring. After adding 2 mg
iodine carrier to the filtered water sample of 1 L, the iodine was isolated and precipitated as AgI. The
129 127

I/ I ratio of AgI target was measured using an AMS system at the Micro Analysis Laboratory Tandem

accelerator (MALT), The University of Tokyo. 127I in the water sample was measured by an ICP-MS at the
University of Tsukuba. The original 129I/127I ratios in the water samples were calculated using 127I
concentration obtained from ICP-MS and 129I/127I ratio obtained from AMS.
129 127

I/ I ratios of the crater lake were (0.4–5.6)×10−9, 2–3 orders of magnitude larger than that of Zao

hot spring ((3.2–5.7)×10−12) which is higher contribution of iodine from the underground, and 1–2 ordersof magnitude lower than that of snow ice ((1.0–1.3)×10−8) including the anthropogenic 129I. Relatively

1Center for Northeast Asian Studies, Tohoku University
Graduate school of Environmental Studies, Tohoku University
3
The University Museum, The University of Tokyo217

high correlation between 129I/127I ratios and 1/127I was found in the three types of water (R2 = 0.69, n = 13),and the depth profile of 129I/127I ratios in the crater lake decreased with depth. Therefore, it is consideredthat iodine in the crater lake primarily originates from the meteoric water and the underground, and it isalso considered that the 129I/127I ratios in the lake were determined by the mixing of both sides.
129 127

I/ I ratios of the crater lake increased from 2.2×10−9 to 5.6×10−9 during October 2013 to the

middle of October 2014, and then abruptly decreased to 4.3×10−10 soon after the second white turbidity(Fig. 1). A relatively strong negative correlation was found between the 129I/127I ratio and monthly volcanic
earthquake (R2 = 0.68, n = 4), and there is a possibility that the 129I/127I ratio in the crater lake is related to
the volcanic activity at Zao volcano. Further investigations are needed for the monitoring of the volcanic
activity.

Fig. 1. Temporal changes in 129I/127I ratio of crater lake (white circles) and monthly volcanic earthquake(black bar [1]) at Zao volcano.
References[1] Japan Meteorological Agency Monthly Volcanic Activity Report 2015 (in Japanese).
[2] X.L. Hou, V. Hansen, A. Aldahan, G. Possnert, O.C. Lind, G. Lujaniene, Anal. Chim. Acta, 632 (2009)
181–196.
[3] U. Fehn, J.E. Moran, G.T. Snyder, Y. Muramatsu, Nucl. Instr. Meth. B 259 (2007) 496–502.
[4] S. Xu, S.P.H.T. Freeman, X.L. Hou, A. Watanabe, K. Yamaguchi, L.Y. Zhang, Environ. Sci. Technol.
47 (2013) 10851–10859.

18

3.4

Technological development for Strontium-90 determination using AMS

Y. Satou, K. Sueki, K. Sasa, T. Matsunaka, T. Takahashi, N. Shibayama1, D. Izumi, N. Kinoshita2, H.
Matsuzaki3
Strontium-90 (90Sr) is a fission product and expected to be released into the environment throughsuch as a nuclear accident. 90Sr quantities are usually measured by chemical isolation of Sr fromenvironmental samples followed by low-level beta counting, however, there are complicated andtime-consuming processes to determine 90Sr. Rapid and simple processes are highly required to evaluate
90

Sr quantities, especially after the nuclear disaster. The Accelerator Mass Spectrometry (AMS) is one ofpotential methods which would solve these problems. We have attempted to develop the 90Sr-AMS using
the 5 MV tandem accelerator at MALT, the University of Tokyo. We report production tests of negative
ion beams and detection tests of 90Zr with the AMS techniques for effective 90Sr measurements. Target
samples of SrF2 were made with chemical separation from the soil at Fukushima. Mixed samples with thepurified SrF2 and PbF2 were pressed in the aluminum sample holder and installed in the MC-SNICS ion
source. The negative ions of 88SrF3- with over 500 nA were successfully extracted from the MC-SNICS ion
source. Natural isobar of 90Zr interferes with 90Sr detection using an ionization chamber. However, in orderto observe the behavior of the 90Sr in gas counter, 90Zr isobar was monitored as 90Sr in this study. After theions passed through a gas stripper, the ions with 90 for mass number and 6+ for charge state, which areconsidered to be 90Zr, were transported to an ionization chamber. The ions with 1000 cps for count rate
were identified in the two-dimensional spectrum in Fig. 1, which correspond to approximately 3 × 10-8 foratom ratio of 90Zr/88Sr in the Sr beam. Further works would provide a successful isobaric separation.
500

Total Energy [channel]

400

Fig. 1. Spectrum of

Zr

90

300

90

200

100

100

200

300

400

Plate 1 Residual Energy [channel]
1

University of Tsukuba, Master’s Programs of Pure and Applied Science
Institute of Technology, Shimizu Corporation
3
MALT, The University of Tokyo
2

19

500

Zr6+ on gas counter.

3.5

Successive searches of iodine-129 contamination in the chemical sample
preparation rooms for AMS

M. Matsumura, K. Sasa, T. Matsunaka, T. Takahashi, Y. Satou, K. Sueki, H. Matsuzaki1
Our research involved measuring 129I (half-life: 1.57 × 107 y) in various samples by Accelerator mass
spectrometry (AMS) [e.g. 1]. This radionuclide’s presence in the atmosphere is attributed to spontaneous
fission of uranium, historical nuclear weapon tests, accidents in nuclear facilities, neutron activation
analysis, and interactions with cosmic rays. Because halogens such as iodine have volatile species, therooms used to prepare samples tend to become gradually contaminated through the chemical treatment ofsamples with high 129I concentrations. AMS can in some cases lead to overestimates of concentrations
mainly due to sample contamination, the memory effect and noise at measurement. A sample has a risk to
be contaminated during its preparation from its environment and also from other samples. It is important
to monitor the contamination in the sample preparation rooms to certify our measurements [2].
We have started monitoring of 129I

129

Table 1 Details of the rooms measured I contamination rates.
129
Low-level I used rooms are located in a building at (A) University of Tsukuba
129
Tandem Accelerator Complex. High-level I used rooms are located in a building at(B) the Center for Research in Isotopes andEnvironmental Dynamics, University ofTsukuba.
Research area
Building
name

Room
name

1

Purpose ofroom use

ConcentrationofKind of sample
129-1
I (atoms g )

―

C304

Desk work

―

―

―

C209

Samplepreparation

Environmental
36
for Cl andfinal

10 to 10

C210

Samplepreparation

Environmental
water

Samplepreparation

Environmental
and soil for
129
I,
enviromental
14
samples for C

107 to 1010

7

10

(UTTAC), Japan, since Aug. 2013 [3].
The 129I monitoring was also performed―

10

method, in a building of University ofTsukuba Tandem Accelerator Complex―

7

AMS sample preparations, by a simple

Ratio of
129 127
I/ I

Desk work

C108

B(Radiation
controlled
area)

Treated samples

C208

A

B

History of
the room use

from air in our rooms usually used forat rooms known as a high129

I

contaminated area in a building of theCenter for Research in Isotopes and

10－11 to 10－5

Environmental Dynamics as well as
rooms unrelated with chemistry as

10 to 10

－11

10

to 10

－5

background at UTTAC, in order tocompare with the results at the sample

10－11 to 10－5

preparation rooms (table 1). Alkaline
trap solutions were placed in the rooms
with each three weeks. Stable (127I) and

Non-RI
room

Samplepreparation

Soil

10 to 10

RI room

Samplepreparation

Soil etc.

< 10

16

10－4 or more

ICP-MSroom

measurement

Liquid for ICPMS< 101310－4 or more

Passage infront of RI
room

Access to
RI room

―

―

―

9

10

10－11 to 10－5

129I

naturally

deposited

from

the

atmosphere into the alkaline trap

The University Museum, The University of Tokyo20

solutions was evaluated. The iodine
collection was repeated up to eighttimes during one year. After three
weeks, the amount of the alkaline trap

solutions

wasobtainedthroughweighing. Then, iodine carrier (with129 127

I/ I = 1.7 × 10−13) was added to thepart of trap solutions, the trapped
iodine was collected as AgI via
chemical purification for AMS. The
129

I /127I ratio in the trap solutions were

determined by AMS at the Micro
AnalysisLaboratory

Tandemaccelerator (MALT), the University ofTokyo,

Japan[4-5].

Measurement

condition was; a terminal voltage wasFig. 1.

129

I contamination rate to the iodine trap solution (barchart) and

129 127

I/ I ratio in the iodine trap solution (white circle).

3.47 MV and charge state was 5+. The
measurement results were normalizedby Purdue standard material (129I/127I =6.54 × 10−11): Z94-0596 provided by PRIME Lab., Purdue University [6], the value was revised in 2014[7]. During all experimental procedures, the blank levels, which included the iodine carrier were 129I/127I =2.0 to 5.6 × 10−13. Also, from the trap solution, approximately 20 mL aliquot was taken for 127I
determination by inductively coupled plasma–mass spectrometry (ICP–MS).
Ambient levels of atmospheric 129I in each room were estimated from the measured concentrations intrap solutions as shown Fig. 1. The unit of 129I contamination rate was multiplied by the weight of theoriginal iodine trap solution and by the area of bottle mouth. Strong contamination was consistently
observed in all of the rooms during Nov. to Dec. 2013. The increase was attributed to the handling ofsolutions with high levels of 129I during that time at a certain room. It is concluded that 129I was diffused by
air and human movement. Although experimental result was at high risk of overestimation during thisperiod, no sample was prepared fortunately. This raised 129I presence then gradually decreased in all of therooms. Except for this contamination point, 129I was found to be present at lower than ~104 atoms cm–2
day–1 in the rooms where no-samples and samples with low levels of 129I were handled. Values of 104 to
105 atoms cm–2 day–1 were recorded in another room where environmental samples were treated. Higher
levels of 129I, ranging from 106 to 107 atoms cm–2 day–1, were recorded in rooms used for treating
neutron-activated iodine. With the exception of the values obtained during Nov. to Dec. 2013, the 129I
contamination rate and the 129I/127I ratio at rooms in UTTAC ranged around 2 × 10−8, which were also
consistent with the 129I level and the 129I/127I ratios of environmental level, from atmospheric fallout
samples in Tsukuba until 2005 [8].
The experimental results show that the 129I depended on the sample-preparation history of the room.
Considering the results of this monitoring, it becomes clear that the sample preparation rooms, in which
we actuary used the samples had no serious 129I contamination. This method is valid and simple. We intend
to continue the monitoring of 129I from air at sample preparation rooms by this method.
This work was supported by JSPS KAKENHI Grant Numbers 24246156 and 24110006.

21

References[1] T. Matsunaka et al., Nucl. Instr. Meth. B, Doi:10.1016/j.nimb.2015.03.056 (available online).
[2] A. Schmidt et al., Sci.Total Environ. 223 (1998)131.
[3] M. Matsumura et al., UTTAC Annual Report 2013 (2014) 31.
[4] H. Matsuzaki et al., Nucl. Instr. Meth. B 259 (2007) 721.
[5] H. Muramatsu et al., Quat.Geochro. 3(2008) 291.
[6] P. Sharma, et al., Nucl. Instr. Meth. B 123 (1997) 347.

[7] M. Caffee, (Purdue University), Personal communication (2014).
[8] C. Toyama, et al., Sci. Technol. 47 (2013) 8383.

22

4.
BEAM AND ISOTOPE APPLICATIONS

4.1

Micro-PIXE analyses of single fluid inclusions in quartz from Tanzawa
granite, Japan

M. Kurosawa, K. Sasa, S. Ishii
Introduction
Fluid released from granitic magma during solidification plays a key role in formation of various
metal-ore deposits, hydrothermal alteration, and chemistries of deep groundwater around granite bodies. A
part of the fluid is normally trapped as fluid inclusions in the solidified granite and surrounding rocks.
Thus, chemical analyses of the inclusions provide useful information about chemistries and behaviors of
the fluid. The Miocene plutonic complex in Tanzawa, Kanagawa Prefecture, Japan, is well known for atypical M-type granite [1] and has isotopic and chemical signatures of basaltic rocks derived from theupper mantle [2]. Fluid-inclusion analyses of the Tanzawa granite, therefore, is expected as an information
source about chemistries of hydrothermal fluids from M-type granite, because the chemical features havebeen poorly characterized. For these reasons, we analyzed trace-element contents in fluid inclusions fromquartz crystals at the Tanzawa granite by using micro-PIXE.
SampleThe Tanzawa plutonic complex is mainly composed of
granite (tonalite) with minor gabbro, and the granite body is
subdivided into several rock types. The Yusin type has highSiO2

contents

(>70

wt.%)

and

demonstrates

highlyfractionated features [2]. Quartz crystals were collected frommiarolitic cavities in the Yusin granite. The quartz included so

NaCl

Bubble
KCl

Fe3O4
FeCl2

many two-phase and polyphase inclusions (Fig. 1), minor
vapor-rich and liquid-rich inclusions, and trace amounts ofliquid-CO2 inclusion. Elemental compositions of the major
two-phase and polyphase inclusions were determined by
micro-PIXE. Salinities of the polyphase inclusions were ofabout 40 wt.% NaCl eq. and the homogenizing temperatures(Th) ranged from 400 to 500 °C. The two-phase inclusions
showed almost Th of 220 to 500 °C.

Fig. 1. Photomicrograph of polyphaseinclusion in quartz crystal from amiarolitic cavity at the Tanzawa
granite, Japan. A large bubble andmany daughter crystals of halite,
sylvite, and so on are present in the
inclusions. Scale bar is a 50 μm.

Experimental
The PIXE analyses were performed at the 1 MV Tandetron. A 0.15 to 0.3 nA beam of 1.92-MeV
proton was focused to a 30 × 30 μm spot on the sample using slits and magnetic lenses. The beamincidence was normal to the sample surface, and the X-ray measurement take-off angle was 45˚ [3,4]. The
characteristic X-rays excited by the incident beam were collected by the Si(Li) X-ray-energy detector23

(Sirius 30+ detector; e2V Scientific Instruments, UK)

Proton beam

X-ray

with a nominal resolution of 139 eV at 5.9 keV. A
55-μm-thick Mylar film was used to attenuate the45

intense X-rays from the predominant light elements andto prevent the entry into the detector of protons scattered

inclusion depth

matrixfrom samples. The total charge was determined by(x,y,z)woXlintegrating the target currents, and all samples wereanalyzed to the integrated charges of 0.4 to 0.9 μC.

t

YZAnalytical points were chosen based on optical viewing

Fluid
inclusionusing a CCD camera mounted on the microscope [4].

Fig. 2. Schematic geometry for PIXE analysis
of fluid inclusion.

Quantification was performed based on the model ofKurosawa et al. [3,4].

Results and Discussion
PIXE spectrum of a polyphase fluid inclusion in
the miarolitic cavities consisted of K X-ray peaks
from Cl, K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, and Sr,and of L X-ray peaks from Pb and Ba (Fig. 3). Mostof polyphase inclusions in the miarolitic cavities
demonstrated the similar X-ray spectra. Element
concentrations

of

the

polyphaseinclusions,determined by PIXE, were as follows: 20 to 25 wt.%
for Cl, 3‒8 wt.% for Fe, 3‒5 wt.% for K, 0.9‒2.7
wt.% for Mn, 1‒1.6 wt.% for Ca, 1000‒5000 ppm forZn, about 2200 ppm for Cu, 200‒1000 ppm for Pb,
700 ppm for Ba, 270‒430 ppm for Br, 30‒280 ppm
for Ge, 80‒200 ppm for Rb, and 0‒140 ppm for Sr.
The values determined for Cu, Ti, and Mn are several
times higher than the values of polyphase inclusions
in miarolitic quartz from the Kofu granite, Yamanashi,

Fig. 3. PIXE spectra of polyphase (upper)
and two-phase (lower) fluid inclusions inquartz crystal from miarolitic cavity at the
Tanzawa granite, Japan.

Japan, which is an I-type Miocene granite [5]. The values for Ge and Sr is extremely lower than those of
the Kofu granite. Elemental contents of the two-phase inclusions were as follows: 2.6 to 3.5 wt.% for Cl,
0.2‒0.4 wt.% for K, 1000‒1900 ppm for Cu, 500‒1700 ppm for Fe, 600‒1900 ppm for Ca, 700‒1700 ppm
for Ba, 300 ppm for Mn, 90 ppm for Zn, 15‒20 ppm for Br, and 0‒30 ppm for Pb and Ge. Rb and Srcontents were undetectable. The extremely lower values of Ge, Rb, Sr, and Pb and the relatively higher
contents of Cu, Ti, and Fe are quite different from those of the I-type Kofu granite [5]. The high contentsof Cu and Ti and the extremely low contents of Ge and Sr is thought to be a chemical feature ofhydrothermal fluids of M-type granite from the comparison to those from the Kofu granite.

24

The high Cu contents of polyphase and two-phase inclusions are consistent with an existence ofsulfide mineral of copper, chalcopyrite, in the miarolitic cavities from the Tanzawa granite. It seems to bemetal concentration enough to form large-scale Cu ore deposits near the granite body. The large-scale ore
deposits, however, are absent around the granite. This may result from an insufficient total-volume ofhydrothermal fluids released from the granite body or lack of concentrated depositions of Cu contents inthe fluids at one place. A quick lift-up and erosion of the shallower part around the Tanzawa area
associated with the arc‒arc collision [2] may be significant for loss of the ore deposits formed often near
the earth’s surface. An elucidation of the lack of Cu ore deposits at the Tanzawa granite would be
important to understanding the cause for absence of a porphyry-Cu type ore-deposits in Japan.
References[1] M. Takahashi, Modern Geol. 14 (1989) 127.
[2] S. Kawate, M. Arima, Island Arc 7 (1998) 342.
[3] M. Kurosawa et al., Geochim. Cosmochim. Acta 67 (2003) 4337.
[4] M. Kurosawa et al., Nucl. Instr. Meth. B 266 (2008) 3633.
[5] M. Kurosawa et al., Island Arc 19 (2010) 40.

25

4.2

Coincidence detecction systeem of ion and seconndary eleectron in HERDA
H

T. Tamura,, I. Harayamma, S. Maeda,, S. Ishii, D. Sekiba
High--resolution Elastic
E
Recoil Detection Analysis (HHERDA) equ
uipped with the 90º sector magnet
and positioon sensitive detector (PSSD) is an efffective tool tot determine the hydrogeen depth disttribution inthin films [1]. While HERDA
H
has an advantagee from the viewpointvof the non-desttructive meth
hod and theability of quantificatioon, its limit of detectionn is not enouugh compared with that of secondary
y ion mass
spectroscoopy (SIMS) ~ 1018 particcles cm-3. Thhe limit of detectiondin a reasonablee data acquiisition time
directly reeflects the raatio between signal and nnoise. In thee case of HE
ERDA, the oorigins of the noise are
attributed tto the dark currentc
produ
uced in the mmicro channel plate (MCP
P) as the PSD
D and the straay particles
scattered ffrom the inner walls of thet vacuum cchamber. On
ne of the effeective solutioons to removve the darkcurrent noise from the data is the coincidencecddetection of thet recoil annd secondaryy electrons em
mitted froma Mylar fiilm set in froont of the PSD. Hashim
moto et al. ap
pplied this coincidence ddetection sysstem to theHigh-resollution Rutheerford backsccattering speectroscopy (HRBS) [2]. The coinciddence detecttion system
improved the limit of detection off HRBS for As in Si [3] and that of HERDA fo
for B in Si [44] with thefactors of 200 and 20, respectively. In the preesent study, we tried to determine thhe limit of detectiondof
HERDA wwith the coinccidence deteection system
m for H in thee hydrogenatted amorphoous carbon (aa-C:H) filmgrown on tthe Si substrrate with chem
mical vapor deposition (CCVD).
Fig. 11. (a) displayys the schemaatics of arranngement of thet two PSDss, electrodess to guide thee secondary
electrons aand the stoppper foil (Myylar, t = 0.5 μm). Fig. 1. (b), on the other hand, shows a piccture of theconstructed system. Baased on the electrodesearrrangement proposedpin Ref.
R [3,4], w
we simply ado
opted a flat
plate for tthe electrodees. The bluee lines in Fiig. 1(a) show
ws the trajeectories of thhe secondaryy electrons
emitted froom the stoppper foil put onn the PSD1.
PSD2

t
f il
PSD1 andd stopper
foil

(aa)

MCP IN : GND(b)Secoondary
electtrons(10 eV)e-2.0 kkV
H+ ion-1.0 kV-1.8 kV-1.5 kV -1.7
7 kV

-2.0 kVV

GND

Fig. 1. (a) Schematics electrodes arrrangement aand electric potentials.
p(bb) A picture oof the newly
y developed
coincidencce detection system.
s

26

The simulation was carried out with a software (SIMION) with an assumption that the initial kinetic
energy of the secondary electrons is 10 eV, while this value is not very much sensitive to the trajectory
because the secondary electrons immediately accelerated up to ~ 0.8 keV with a Cu mesh toward thePSD2. We can see that the secondary electrons are perfectly collected by PSD2 with the present simple
arrangement of electrodes.
Fig. 2 shows the obtained HERDA spectra taken on the a-C:H film with and without the coincidence
detection system. In the experiments, 1 MeV 16O+ was used as the incident beam, and the data acquisition
time and irradiation were ~ 300 sec and 5.4 μC, respectively, monitored by a beam chopper. As a result,
we observed a remarkable reduction of the dark current noise clearly appeared in the vacuum region of
530 ch ~ 850 ch. The signals of recoils seen in the region of 300 ch ~ 520 ch, however, also showed asignificant reduction due to the coincidence detection system. As a total system, the HERDA with thecoincidence detection system exhibits the better performance not only for B, but also for H. The problemof the signal loss should be improved in future. In other words, the solution of the signal loss will give us afurther major improvement of the limit of detection. The most likely reason of the signal loss seen in the H
detection will be a small amount of the emitted secondary electrons induced by the H penetration throughthe stopper foil. Some coating of the stopper foil to enhance the secondary electron emission might be an
efficient improvement in a future work, while some other possible problems, for example, non-suitablesetting of time gate generation should be carefully removed.
350
16

Yield(counts)+

probe ions : 1 MeV O
target : a-C:H/Si
measurement time : 300 sec-6
2
beam irradiation : 5.4×10 C/mm

300
250
200

― non-coincidence― coincidence

150
100
50
0
300

400

500

600

700

800

Particle Energy(ch)Fig. 2. HERDA spectra taken on the same a-C:H film with (red) and without (green) the coincidence
detection system.
References[1] K. Kimura, K. Nakajima, H. Imura, Nucl. Instr. Meth. B 140 (1998) 397-401.
[2] K. Kimura, M. Mannami, Nucl. Instr. Meth. B 113 (1996) 270-274.
[3] H. Hashimoto, K. Nakajima, M. Suzuki, K. Sasakwa, K. Kimura, Rev. Sci. Instrum. 82 (2011) 063301.
[4] H. Hahimoto, S. Fujita, K. Nakajima, M. Suzuki, K. Sasakawa, K. Kimura, Nucl. Instr. Meth. B 273(2012) 241-244.

27

4.3

Straggling effect in channeling on Si(100) with metal thin films

E. Noguchi, D. Sekiba, I. Harayama, Y. Watahiki, S. Ishii
Recently various metal thin films have been grown on substrates by means of chemical vapor
deposition (CVD). In contrast to physical vapor deposition (PVD) with the magnetron sputtering, themetal thin films obtained by CVD in principle contain the light elements come from the original processgas, which are usually organic metals. The physical and chemical properties of the metal thin films
strongly reflect those contaminations. Therefore the knowledge on the light element distributions areimportant. When the thickness of an interesting metal film is several nano-meters, high-resolution
Rutherford backscattering spectroscopy (HRBS) [1] with channeling is effective to determine the lightelement distribution in the metal film grown by CVD on a single crystal. In our experience, however, thechanneling effect is rapidly suppressed with increasing the film thickness above ~5 nm. To determine themaximum film thickness suitable to the light element distribution analysis by HRBS, we survey the film
thickness dependence of yield suppression in channeling on the Pd/Si(100) system.
Five samples were prepared with changing the thickness of the Pd films (t = 4, 8, 9, 13, 14 nm)
grown by PVD with the magnetron sputtering on the Si(100) substrate. The dimension of the substrates
was 15 mm x 15 mm x 0.5 mm, and the substrate was cleaned fluoric acids before the Pd film deposition.
For the channeling measurements, the Si<110> axis was used. The beam incident angle was set at θ = 45ºfrom the surface normal, and then the azimuthal angle ω was swept to observe the channeling dip.
HRBS1000 system supplied by KOBELCO with the 1 MV single-end electrostatic accelerator was used.
The 400 keV He+ beam with a typical current of several tens nA was shaped to 1 mm x 1 mm with adouble slit system. The detection angle for the scattered particle was set at 80º with respect to the beamincident direction.
Fig. 1 shows a typical RBS spectrum taken on Pd (t = 8 nm) / Si(100) with the <110> channeling. An
intense peak corresponding to the Pd film is seenin the energy region from 360 keV to 380 keV.
suppressed due to the channeling, and the leadingedge is observed at ~315 keV. The channeling
dips depending on the Pd film thickness wereplotted by collecting the yield corresponding to

1500

Yield [counts]

The signals from the Si substrate are well

1000

Pd
ROI

500

Si

the Si subsurface region indicated by the gray0

hatch (ROI: Region of Interest).

280

300

320

340

360

380

Energy [keV]

Fig. 2(a) shows the channeling dips taken on

Fig. 1. RBS spectrum taken on Pd (t = 8 nm) /Si(100) with the <110> channeling condition.

the five samples around the <110> channeling28with changing the azimuthal angle ω: Pd (t = 4 ~ 24 nm) on Si(100). The yield on the random spectrum

Yrandom is ~800 counts. We can see that the yield at the bottom of the dip Ymin increases with increasing
the Pd film thickness. Some satellite dips beside the <110> channeling, which correspond to other planar
channeling, are also observed when the Pd film thickness is small. Fig. 2(b) displays the minimum yieldratio

χ min = Ymin Yrandom depending on the Pd film thickness. While χ min = 0.16 was obtained on thePd (t = 4 nm) /Si(100), the χ min increased up to ~ 0.4 over the film thickness of 10 nm. The value χ min= 0.4 is no longer suitable to the measurements of light element distribution. We tried to interpret theobserved behavior of χ min by a theory taking mainly the angular straggling of trajectory to the account~[2]. Here primary concept is that the effective critical angle for the channeling θ c is reduced from theoriginal value ψ c by the angular straggling when there is a non-crystalline film on the Si(100) single~

crystal as follows. θ c =aE
ψ c . Where “ a ” is the Thomas-Fermi screening radius “ E ” is the2 Z He Z Pd e 2

energy of the incident He beam, “ e ” is the elementary electric charge, Z He and Z Pd are the atomic
number of He and Pd, respectively. We can see that the theory well reproduced the present experimental
data. From this theoretical model, we survey the experimental condition, which enables us to achieve

χ min = ~0.16 with the Pd film thickness of 10 nm. One of the simple solutions is the increase of the He
beam energy to suppress the reduction of the effective critical channeling angle. In this case, the He beamenergy more than 500 keV is necessary according to the theory. The examination of the beam energy
dependence of χ min is remained for the future works.
1.0

600

0.6

400
200
0

present exp.
theory from Ref[2]

0.8

χmin

Yield [counts]

800

(a)
-15

-10

0.4

4 nm
8 nm
9 nm
13 nm
24 nm

-5

0

5

10

0.2

15

0

(b)
0

5

ω [degree]

10

15

20

25

30

Pd thickness [nm]Fig. 2. (a) The channeling dips taken on Pd (t = 4 ~ 24 nm) /Si(100) at the <110> channeling. (b) Pd
thickness dependence of minimum yield ratio χmin.
References[1] K. Kimura, M.Mannami, Nucl. Instr. Meth. B 113 (1996) 270-274.
[2] D.S. Gemmell, Rev. Mod. Phys. 46 (1974) 129-227.

29

4.4

Mössbauer spectroscopy of ferromagnetic
developed for magnetic hyperthermia

Fe3O4

nanoparticles

H. Latiff, A. Horiuchi, M. Kishimoto, H. Yanagihara, E. Kita
In the application of ferromagnetic nanoparticles to magnetic hyperthermia, coercive force control is
an important requirement for effective hysteresis-loss heating within the human-safe limit amplitude H0
and frequency f0 of alternating magnetic field (AMF). Cobalt-contained iron oxide particles weresynthesized previously, and the coercive forces was finely tuned according to the Co content. However
due to the possible toxicity of cobalt, we attempted to attain coercive force control by introducing theshape anisotropy and synthesized platelet γ-Fe2O3 and Fe3O4 nanoparticles. In this report, platelet Fe3O4
nanoparticles was synthesized and the morphology of particles was investigated using Mössbauer
spectroscopy.
Platelet α-FeOOH, used as the precursor materials were synthesized by precipitation andhydrothermal treatment. The α-FeOOH particles were dispersed in tetraethylene glycol (TEG), and heatedto the preferred temperature for a certain period of time. TEG is used as the reducing agent in the reaction.
The obtained product was washed with ethyl alcohol and then dried in air to powdered form.
Magnetizations of dry powdered samples were measured using a vibrating sample magnetometer (VSM)
and the variation in crystal structures were examined using X-ray diffraction (XRD). Mössbauer
spectroscopy was carried out at room temperature and the velocity and isomer shift were calibrated
relative to α-Fe. Data were analyzed using an analysis program, MossWin Ver.4.
Fig. 1 shows the XRD spectra of reduction products heated at 310°C for 5 – 120 minutes. Diffraction
peaks attributable to the spinel structure increased with increasing reaction time. After heating for 60 –120 minutes, single phase spinel structured products were obtained, showing the α-FeOOH particles havecompletely been reduced to Fe3O4.
Fig. 2 shows the room temperature Mössbauer spectra of reduction particles obtained in Fig. 1. Eachspectrum was fitted to a combination of two or three magnetic sextets corresponding to Fe oxides and one
singlet component. The area ratios of the respective sub-spectra are shown in Fig. 3(a).

Fitting

parameters are tabulated in Table 1. From the result, it is clear that as the heating time increases, the Fe3O4
ratio increases with the expense of α-Fe2O3. After 120 minutes, all α-FeOOH have been completely
reduced to Fe3O4. The singlet component observed in sample heated for 5 minutes, is considered tooriginate from non-crystalline component which appear during the dehydration process of α-FeOOH. As
the reaction time increases, particles grow larger and crystallinity tends to improve thus reducing thesinglet component.
Fig. 3(b) shows the magnetic properties of reduction products obtained by heating the
α-FeOOH/TEG dispersion at 310°C for 5 – 120 minutes. The saturation magnetization increases rapidly
initially and eventually reaches a saturated value. This is due to the rapid formation of magnetic Fe3O4
particles in the earlier stage. The coercive forces were almost constant against the reaction time andindependent from the saturation magnetization. Although high coercive force has been reported in α-30

Fe2O3 fine particles, relatively low coercive forces for samples including α- Fe2O3 is possibly due to thesuperparamagnetic relaxation coming from the small particle volumes and magnetic anisotropy. Fe3O4
particles obtained after heating for 60 minutes have saturation magnetization of 83 Am2/kg and coercive
force of 13 kA/m. The increase of Fe3O4 in expense of α-Fe2O3 was also confirmed by Mössbauer
spectroscopy analysis shown in Fig. 2 and Fig. 3(a).

experimentfit
3+
Fe (hematite)3+
Fe (A)
2.5+
Fe (B)
singletSpinel× α-Fe2O3

tR: 120 min.

tR: 120 m

Intensity (arb. units)

Intensity (arb. unit)tR: 60 min.

tR: 30 min.

tR: 5 min.

30

tR: 30 m

×
×

×

20

tR: 60 m

×

×

×

40

50

2θ (deg.)tR: 5 m

×

-10

60

Fig. 1. XRD spectra of the reduction
products obtained by heating the
α-FeOOH/TEG dispersion at 310°C for 5 –120 minutes. Dehydration and reduction
process of α-FeOOH occurs simultaneously
during the first 5 minutes. Reduction process
was finally completed after 60 minutes.

-50Velocity (mm/s)

510Fig. 2. Mössbauer spectra of samples obtained inFig. 1 recorded at room temperature. The spectra
were fitted to a set of two or three magnetic sextets
corresponding to the respective Fe oxides and asinglet component which is considered to originate
from non-crystalline component. Reaction times, tR
are 5 – 120 minutes.
TABLE 1.
MÖSSBAUER PARAMETERS FOR SPECTRA IN

(a)

80
60

α−Fe2O3

40

Fe3O4

100

Hhf
(T)

I. S.
(mm/s)Q. S. Population(mm/s)(%)

5

Fe (hematite)

3+

50.6

0.37

-0.21

22.7

3+

Fe (A)

49.1

0.33

-0.10

34.2

2.5+

45.6

0.63

0.00

26.1

-

0.45

-

17.0

14

80

8
6

40
20
20

40

60

80

MS

4

HC

2

100

120

(B)

Singlet

10

60

0

Fe

12

(b)

MS (Am /kg)

2

Ion (site)

singlet20

0Reactiontime (min.)HC (kA/m)

Population (%)

100

30

3+

Fe (hematite)

49.2

0.37

-0.20

4.5

Fe (A)

3+

48.9

0.29

-0.02

31.5

2.5+

45.72

0.67

0.00

51.7

-

0.38

-

12.3

Fe

(B)

Singlet

060

Reaction time (min.)3+

Fe (hematite)

49.5

0.37

-0.12

2.4

3+

Fe (A)

49.1

0.31

-0.02

42.3

2.5+

45.9

0.65

0.00

51.8

Fe

Fig. 3. (a) Population of α-Fe2O3, Fe3O4, andsinglet component deduced from Mössbauer
spectra. (b) Saturation magnetizations andcoercive forces of reduction products obtained inFig. 1.

120(B)Singlet

-

0.50

-

3.5

Fe (A)

3+

49.05

0.29

-0.00

37.9

2.5+

45.83

0.65

0.00

60.7

-

-0.52

-

1.4

Fe

(B)

Singlet31

4.5

Conversion electron Mössbauer spectroscopy (CEMS) of cobalt ferrite
thin films

R. Aoyama, H. Yanagihara, K. Mibu1, E. Kita
High perpendicular magnetic anisotropy (PMA) materials have attracted attention because of theirpotential use in magnetic recording media and other practical applications. In addition to high PMA,
materials that do not contain Pt, a rare metal, are ideal for the future uses to avoid resource issues such as
scarcity. The magnetization and PMA of cobalt ferrite thin films, which are high PMA materials, changewith composition and production conditions. As such, cobalt ferrite thin films are the subject of our study,
and we have reported changes in their magnetization and PMA by changing their composition andproduction conditions [1].
In order to clarify the mechanism of anisotropy in cobalt ferrite thin films, the electronic andmagnetic states should be studied using Mössbauer spectroscopy. However, it is not possible to detect
these electronic and magnetic states via transmission through the sample in thin films grown on thicksubstrates. Conversion electron Mössbauer spectroscopy (CEMS) can be used on such samples because
the electrons emitted back from the surface are detected. However, it takes a long time to gather CEMS
results from samples thinner than 100 nm because of the insufficient amount of 57Fe nuclei in cobalt ferrite
thin films. To decrease measurement time, we prepared a locally enriched 57Fe target [2].
The locally 57Fe enriched target was composed of a 1 mm thick doughnut shaped 57Fe enriched disk,
covering the erosion part of sputtering, and a natural Fe base plate. Cobalt ferrite thin films were grown on
MgO(001) single crystal substrates by co-sputtering using the locally enriched 57Fe target and Co target.
The O2 flow rate was set to 7 sccm and the substrate temperature was fixed at 600 ºC during sputtering.
Fig. 1 shows a CEMS spectrum for a Co0.65Fe2.35O4 thin film. The time to collect data of equivalentquality was ideally shortened by a factor of ten because the amount of 57Fe was 25% in the enriched target
compared to 2.3% in natural Fe. Data collected for 16 hours is shown in Fig. 2, and the spectrum has adistinct enough signal to noise ratio for detailed discussion. The enriched 57Fe combination target enabled
us to shorten measuring time drastically and will be a powerful tool in analyzing the magnetic state of Fe
based thin films.
The spectrum was fit to a combination of three ferromagnetic sub-spectra, and the result is shown in
Fig. 2. The spectrum was fairly symmetric and the isomer shifts were 0.3–0.4 and were fairly similar to
those of trivalent Fe ions. It was supposed that about 15% (= 0.35·2.35−1) of Fe atoms were in the divalentstate that is not clearly seen in the spectrum. This suggested that the film was well oxidized and thenumber of divalent Fe atoms was small. Sites with small hyperfine fields (site 1) may be attributed to thesurface Fe atoms.

1

Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan32

References[1] T. Niizeki, Y. Utsumi, R. Aoyama, H. Yanagihara, J. Inoue, Y. Yamasaki, H. Nakao, K. Koike, Eiji Kita,
Appl. Phys. Lett. 103 (2013) 162407, ibid.104 (2014) 059902 [erratum].
[2] R. Aoyama, H. Yanagihara, Ko Mibu, E. Kita, UTTAC Annual report 2013 (2014) 17.

X = 0.04

Fig. 1. Conversion electron Mössbauer
spectroscopy (CEMS) spectrum for the
CoxFe3-xO4 thin films recorded at 300 K.
Solid lines indicate fitted results.

Counts (arb.)

X = 0.12

X = 0.23

X = 0.65

X = 0.94

-10

-5

0

5

10

Velocity (mm/s)
Table 1. Mössbauer fitting parameters for the CoxFe3-xO4 thin films.

*Isomer shift with respect to α-Fe

33

4.6

Magnetization control of Co ferrite thin films by Kr ion implantation

Y. Liu, E. Kita, H. Yanagihara, K. Mibu1, D. Oshima2, T. Kato3, S. Iwata 2
According to the increasing demand for high-density recording devices, perpendicular magnetic
recording systems have emerged as the predominant hard disk system. For further increase of recording
density, stronger perpendicular magnetic anisotropy (PMA) and bit pattern media (BPM) [1] are focused.
For BPM, lithography, the imprint technique, or ion implantation have been tested. Ion implantation has
been adapted to metallic PMA substances, however, there has been no research on the oxide ferromagnets.
Using this technique, one can change/control a magnetic state of materials from ferromagnetic tononmagnetic, which may render the fill-back process in other lithography techniques unnecessary. We
have performed magnetization control by ion implantation on Fe3O4 thin films as a basic material of spinel
type ferromagnetic oxides.[2,3] Effects of Kr ion implantation was confirmed by Mössbauer study.[3] In
this study, a ferromagnetic Co ferrite (CFO) with PMA is focused and the magnetization of them iscontrolled by Kr ion implantation. We chose the thin films with a concentration of x = 0.75 because theconcentration realized high magnetization and PMA.[4]The thin films of Co ferrite (x=0.75, CoxFe3-xO4) (13 nm) were grown on polished MgO (001) substrates
with a reactive sputtering in an RF planar magnetron sputtering system. In order to perform the Mössbauer
spectroscopy measurements, the thin films were fabricated with the Co target and the 57Fe enrichedtargets.[5] Reflection High Energy Electron Diffraction (RHEED) was used to confirm surface crystalline
structure, X-Ray Fluorescence (XRF) was used to analyze the atomic density of Fe and Co atoms, and a
SQUID magnetometer was used to measure the magnetization process. Co ferrite thin films were covered
with an 15 nm carbon layer prior the ion implantation to prevent a decrease in thickness due to the
sputtering by ion beam implantation. Kr ions were accelerated at 30 kV in a conventional ion implantation
system.
The influence of Kr ions to the magnetization of Co ferrite thin films was indicated together with thatfor Fe3O4 reported previously[3] in the Fig. 1. The magnetization decreases with the increase of ion dose,
and the magnetization of thin films reaches to almost zero when the dose of ions is enough. It is concluded
that both thin films are controlled well by Kr ion implantation from these results.
Fig. 2 shows the Mössbauer spectra before and after ion implantation. As-prepared sample shows the
spectrum with a distributed hyperfine field. The fitting with three hyperfine fields was carried out.
Isomer shifts for subspectra were almost the same magnitude for those of Fe3+ ions. After 1×1015 ions/cm2
Kr ions implantation, the ferromagnetic subspectra became small, and the nonmagnetic subspectra became
larger. After ion implantation by 1×1016 ions/cm2 Kr ions, the ferromagnetic subspectra shown in the
before-ion-implantation sample almost disappeared. It is concluded that the decrease in the magnetizationof Co ferrite thin films is due to the Kr ion implantation.
1

Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Aichi, Japan.
EcoTopia science Institute, Nagoya University, Nagoya, Aichi, Japan3
Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya, Aichi, Japan.
2

34

From these, it is considered that the structure of CFO thin film changed partly by the weak Kr ion
implantation, and the strain resulting PMA was released. After further implantation, the structure changed
into that seen in the Kr irradiated Fe3O4 thin films and the magnetization decreased.
(a) CFO without irradiation

Fe3O4 Bulk
400

Kr ions CFO
Kr ions Fe3O4
N2 ions Fe3O4

CFO (70 kOe)

300

200

100

0
13
10

10

14

15

10

10

16

10

17

2

Dose ( ions/cm )Fig. 1. Influence of Kr ion implantation tomagnetization of the Co ferrite thin film andFe3O4 thin films[3].

Counts (arb.)

3

Ms(H=10 kOe) (emu/cm )500(b) Kr ion irradiation
15

1 x 10ions/cm2(c) Kr ion irradiation
16

1 x 10ions/cm2

Fig. 2. Mössbauer spectra of Co ferrite thin films (a)without ion implantation, (b) with the dose 1×1015
ions/cm2 ion implantation and (c) with the dose 1×
1015 ions/cm2 ion implantation.

-10

-5

0

5

10

Velocity (mm/s)

Table 1. Mössbauer fitting parameters for a Co0.75Fe2.25O4 thin film without ion implantation.
1
1
Sub-spectrum Hhf (T) IS* (mm·s− ) Line Width(mm·s− )Area (%)

Estimated site

F1

44.03

0.329

1.034

38.0

B

F2

48.32

0.314

0.496

39.5

A

0.501

22.5

B

F3
50.80
0.351
*Isomer shift with respect to α-Fe
Acknowledgement

Kr ion implantation was performed at Nagoya University with the support of Nanotechnology Platform.
References[1] B. D. Terris, J. Magn. Magn. Mater. 321 (2009) 512.
[2] E. Kita et al., Jpn. J. Appl. Phys. 53 (2014) 020306.
[3] E. Kita et al., J. Appl. Phys. 115 (2014) 17B907.
[4] T. Niizeki et al., Appl. Phys. Lett. 103 (2013) 162407, ibid. 104 (2014) 059902.
[5] R. Aoyama et al., UTTAC Annual report 2013 (2014) 17.

35

4.7

Oxygen and sulfur isotopic analysis of ion-induced sulfate production
reaction initiated via proton beam

S. Ishino1, S. Hattori1, S. Tomita, Y. Nakai2, N. Yoshida1
Ionizing radiation of galactic cosmic ray (GCR) has been recognized as one of the factors influencing
the Earth’s cloudiness [1]. It has been shown that sulfate is produced and forms small droplets by ionizing
radiation [2], but the underlying mechanisms of ion-induced reaction have not yet been identified and theircontribution to the atmosphere is still not known.
In order to elucidate the mechanism, we investigated the production of sulfate during ion-induced
reaction via proton beam using 1 MV Tandetron accelerator at the University of Tsukuba Tandem
Accelerator Complex (UTTAC). The experiments were conducted in two different conditions of thechamber atmosphere; 20 ppm SO2 mixture in wet air including 20% O2 (Air mode) and wet N2 without O2(N2 mode) at relative humidity of 40% and flow rate of 1.0 L min–1. The produced sulfate was collectedwith PTFE filter (JGWP04700, Merck Millipore) and residual SO2 was collected by Fe2+/Fe3+ solution.
Oxygen and sulfur isotope ratios of sulfate and SO2 were measured using isotope ratio mass spectrometry.

Fig. 1.

Experimental setup.

17

Positive Δ O of sulfate was observed in Air mode, while Δ17O of sulfate in N2 mode was almost zero.
Positive Δ17O of sulfate in Air mode indicates the contribution of O3, and these results are consistent with
SO2 oxidation by O3–(H2O)x clusters, which was predicted through theoretical study [3]. Note that Δ17O of
sulfate in Air mode was smaller than that of atmospheric O3 suggesting the contribution of other reactions.
For N2 mode, on the other hand, the approximately 0‰ of Δ17O for sulfate might be due to SO2 reaction
with OH, which was produced by H2O decomposition promoted by proton beam.1

1

Department of Environmental Chemistry and Engineering and Department of Environmental Science and Technology, Tokyo
Institute of Technology, Yokohama 226-8502, Japan
2
Radioactive Isotope Physics Laboratory, RIKEN Nishina Center, Wako, Saitama 351-0198, Japan36

Table 1. Δ17O values of produced sulfate in this study, sulfate calculated in the model
based on Savarino et al. [4], and assumptions about the atmospheric oxidants

For the sulfur isotopic compositions (δ34S), there was no significant difference between N2 mode andAir mode. However, the δ34S values observed in this study were much smaller than that of the major
atmospheric sulfate productions in previous study [9, 10].

Fig. 2. Comparison of sulfur isotopic fractionation between sulfate production reactions inthis study and previous studies.
References[1]

H. Svensmark, E. F. Christensen, J. Atmos. Solar-Terrestrial Phys. 59, 11 (1997) 1225-1232.

[2]

H. Svensmark, J. O. P. Pederson, N. D. Marsh, M. B. Enghoff, U. I. Uggerhoj, Proc. R. Soc. A 463(2007) 385-396.

[3]

N. Bork, T. Kurtén, H. Vehkamäki, Atmos. Chem. Phys. 13 (2013) 3695-3703.

[4]J. Savarino, C. C. W. Lee, M. H. Thiemens, J. Geophys. Res. 105, D23 (2000) 29079-29088.

[5]

B. D. Holt, R. Kumar, P.T. Cunningham, Atmos. Environ. 15, 4 (1981) 557-566.

[6]

E. Barkan, , B. Luz, Rapid Commun. Mass Spectrom. 19 (2005) 3737-3742.

[7]

G. Michalski, S. K. Bhattacharya, G. Girsch, Atmos. Chem. Phys. 14 (2014) 4935-4953.

[8]J. Savarino, M. H. Thiemens, J. Phys. Chem. A 103, 46 (1999) 9221-9229.

[9]E. Harris, B. Sinha, P. Hoppe, S. Ono, Environ. Sci. Technol. 47, 21 (2013), 12174-12183.

[10] M. B. Enghoff, N. Bork, S. Hattori, C. Meusinger, M. Nakagawa, J. O. P. Pedersen, S. Danielache,
Y. Ueno, M. S. Johnson, N. Yoshida, H. Svensmark, Atmos. Chem. Phys. 12 (2012) 5319-5327.

37

5.
PUBLICATIONS

5.1

Journals

ACCELERATOR AND EXPERIMENTAL FACILITIES
1.

S. Tomita, Y. Shiina, S. Tamura, R. Kinoshita, S. Ishii, K. Sasa, “Measurement of backward
secondary-electron yield under molecular ion impact coincident with emerging projectiles”, Nucl.
Instrum. Meth. Phys. Res. B 354 (2015) 109.

NUCLEAR PHYSICS
2.

Y. G. Ma, D. Q. Fang, X. Y. Sun, P. Zhou, Y. Togano, N. Aoi, H. Baba, X. Z. Cai, X. G. Cao, J. G.
Chen, Y. Fu, W. Guo, Y. Hara, T. Honda, Z. G. Hu, K. Ieki, Y. Ishibashi, Y. Ito, N. Iwasa, S. Kanno,
T. Kawabata, H. Kimura, Y. Kondo, K. Kurita, M. Kurokawa, T. Moriguchi, H. Murakami, H.
Ooishi, K. Okada, S. Ota, A. Ozawa, H. Sakurai, S. Shimoura, R. Shioda, E. Takeshita, S. Takeuchi,
W. D. Tian, H. W. Wang, J. S. Wang, M. Wang, K. Yamada, Y. Yamada, Y. Yasuda, K. Yoneda, G. Q.
Zhang, T. Motobayashi, “Different mechanism of two-proton emission from proton-rich nuclei 23Al
and 22Mg”, Phys. Lett. B 743 (2015) 306.

3.

T. Moriguchi, A. Ozawa, S. Ishimoto, Y. Abe, M. Fukuda, I. Hachiuma, Y. Ishibashi, Y. Ito, T.
Kuboki, M. Lantz, D. Nagae, K. Namihira, D. Nishimura, T. Ohtsubo, H. Ooishi, T. Suda, H. Suzuki,
T. Suzuki, M. Takechi, K. Tanaka, T. Yamaguchi, “Density distribution of 14Be from reaction
cross-section measurements”, Nucl. Phys. A 929 (2014) 83.

4.

A. Ozawa, T. Moriguchi, T. Ohtsubo, N. Aoi, D. Q. Fang, N. Fukuda, M. Fukuda, H. Geissel, I.
Hachiuma, N. Inabe, Y. Ishibashi, S. Ishimoto, Y. Ito, T. Izumikawa, D. Kameda, T. Kubo, T.
Kuboki, K. Kusaka, M. Lantz, Y. G. Ma, M. Mihara, Y. Miyashita, S. Momota, D. Nagae, K.
Namihira, D. Nishimura, H. Ooishi, Y. Ohkuma, T. Ohnishi, M. Ohtake, K. Ogawa, Y. Shimbara, T.
Suda, T. Sumikama, H. Suzuki, S. Suzuki, T. Suzuki, M. Takechi, H. Takeda, K. Tanaka, R.
Watanabe, M. Winkler, T. Yamaguchi, Y. Yanagisawa, Y. Yasuda, K. Yoshinaga, A. Yoshida, K.
Yoshida, “Charge-changing cross sections of 30Ne, 32,33Na with a proton target”, Phys. Rev. C 89
(2014) 044602.

5.

T. Komatsubara, S. Kubono, T. Hayakawa, T. Shizuma, A. Ozawa, Y. Ito, Y. Ishibashi, T.
Moriguchi, H. Yamaguchi, D. Kahl, S. Hayakawa, Dam Nguyen Binh, A. A. Chen, J. Chen, K.
Setoodehnia, and T. Kajino, “Excited states above the proton threshold in 26Si”, Eur. Phys. J. A 50
(2014) 136.

6.

M. Takechi, S. Suzuki, D. Nishimura, M. Fukuda, T. Ohtsubo, M. Nagashima, T. Suzuki, T.

38

Yamaguchi, A. Ozawa, T. Moriguchi, H. Ohishi, T. Sumikama, H. Geissel, N. Aoi, Rui-Jiu Chen,
De-Qing Fang, N. Fukuda, S. Fukuoka, H. Furuki, N. Inabe, Y. Ishibashi, T. Itoh, T. Izumikawa, D.
Kameda, T. Kubo, M. Lantz, C. S. Lee, Yu-Gang Ma, K. Matsuta, M. Mihara, S. Momota, D.
Nagae, R. Nishikiori, T. Niwa, T. Ohnishi, K. Okumura, M. Ohtake, T. Ogura, H. Sakurai, K. Sato,Y. Shimbara, H. Suzuki, H. Takeda, S. Takeuchi, K. Tanaka, M. Tanaka, H. Uenishi, M. Winkler, Y.
Yanagisawa, S. Watanabe, K. Minomo, S. Tagami, M. Shimada, M. Kimura, T. Matsumoto, Y. R.
Shimizu, M. Yahiro, “Evidence of halo structure in 37Mg observed via reaction cross sections andintruder orbitals beyond the island of inversion”, Phys. Rev. C 90 (2014) 061305(R).
7.

T. Yamaguchi, A. Enomoto, J. Kouno, S. Yamaki, S. Matsunaga, F. Suzaki, T. Suzuki, Y. Abe, D.
Nagae, S. Okada, A. Ozawa, Y. Saito, K. Sawahata, A. Kitagawa, S. Sato, ”Cherenkov lightdetection as a velocity selector for uranium fission products at intermediate energies”, Nucl.
Instrum. Meth. Phys. Res. A 766 (2014) 123.

8.

T. Komatsubara, S. Kubono, T. Hayakawa, T. Shizuma, A. Ozawa, Y. Ito, Y. Ishibashi, T.
Moriguchi, H. Yamaguchi, D. Kahl, S. Hayakawa, Dam Nguyen Binh, A. A. Chen, J. Chen, K.
Setoodehnia, T. Kajino, “Excited states above the proton threshold in 26Si”, Euro. Phys. J. A 50
(2014) 136.

9.

E. Mcneice, K. Setoodehnia, B. Singh, Y. Abe, D. N. Binh, A. A. Chen, J. Chen, S. Cherubini, S.
Fukuoka, T. Hashimoto, T. Hayakawa, Y. Ishibashi, Y. Ito, D. Kahl, T. Komatsubara, S. Kubono, T.
Moriguchi, D. Nagae, R. Nishikiori, T. Niwa, A. Ozawa, T. Shizuma, H. Suzuki, H. Yamaguchi, T.
Yuasa, “In-beam γ-ray spectroscopy of 30P via the 28Si(3He, pγ)30P reaction”, Nucl. Data Sheets 120(2014) 88.

ACCELERATOR MASS SPECTROMETRY
10.

Y. Satou, K. Sueki, K. Sasa, J. Kitagawa, S. Ikarashi, N. Kinoshita, “Vertical distribution andformation analysis of the 131I, 137Cs, 129mTe, and 110mAg from the Fukushima Dai-ichi Nuclear Power
Plant in the beach soil”, J. Radioanal. Nucl. Chem. 303(2) (2015) 1197.

11.

T. Matsunaka, K. Sasa, K.Sueki, T. Takahashi, M. Matsumura, Y. Satou, J. Kitagawa, N. Kinoshita,
H. Matsuzaki, “Post-accident response of near-surface 129I levels and 129I/127I ratios in areas close to
the Fukushima Dai-ichi Nuclear Power Plant, Japan”, Nucl.
http://dx.doi.org/10.1016/j.nimb.2015.03.056.

39

Instrum. Meth. Phys. Res. B, (2015)

BEAM AND ISOTOPE APPLICATIONS
12.

D. Oka, Y. Hirose, H. Kamisaka, T. Fukumura, K. Sasa, S. Ishii, H. Matsuzaki, Y. Sato, Y. Ikuhara,
T. Hasegawa, “Possible ferroelectricity in perovskite oxynitride SrTaO2N epitaxial thin films”,
Scientific Reports 4 (2014) 4987.

13.

H. Iida, S. Iguchi, N. Teramoto, K. Koshino, T. Zeniya, A. Yamamoto, N. Kudomi, T. Moriguchi, Y.
Hori, J. Enmi, H. Kawashima, N. J. Shah, J. Nakagawara. “Adequacy of a compartment model for
CMRO2 quantitation using
15

15

O-labeled oxygen and PET – A clearance measurement ofO-radioactivity following intra-carotid bolus injection of 15O-labeled oxy-hemoglobin on Macaca

fascicularis”, Journal of Cerebral Blood Flow & Metabolism 34 (2014) 1434.
14.

K. Koshino, K. Fukushima, M. Fukumoto, Y. Hori, T. Moriguchi, T. Zeniya, Y. Nishimura, K. Kiso,
H. Iida, “Quantification of myocardial blood flow using 201Tl SPECT and population based input
function”, Ann. Nucl. Med. 28(9) (2014) 880.

15.

Y. Hori, Y. Hirano, K. Koshino, T. Moriguchi, S. Iguchi, A. Yamamoto, J. Enmi, H. Kawashima, T.
Zeniya, N. Morita, J. Nakagawara, M. Casey, H. Iida, “Validity of using a 3-dimensional PET
scanner during inhalation of 15O-labeled oxygen for quantitative assessment of regional metabolic
rate of oxygen in man”, Phys. Med. Biol. 59 (2014) 5593.

16.

T. Temma, K. Koshino, T. Moriguchi, J. Enmi, H. Iida, “PET quantification of cerebral oxygen
metabolism in small animals”, Scientific World Journal, 2014 (2014) 159103.

17.

Y. Hata, K. Yamaugchi, K. Kinoshita, E. Kita, T. Mochiku, H. Yasuoka, “Fe ion distribution andsuperconductivity of FeSr2RECu2O6+y (RE = Eu, Er, Gd, Nd and Y)”, Physica C 507 (2014) 85.

18.

K. Ito, T. Sanai, Y. Yasutomi, T. Gushi, K. Toko, H. Yanagihara, M. Tsunoda, E. Kita, T.
Suemasu, ”Mössbauer study on epitaxial CoxFe4-xN films grown by molecular beam epitaxy”, J.
Appl. Phys. 117 (2015)17B717.

19.

K. Kurita, D. Sekiba, I. Harayama, K. Chito, Y. Harada, H. Kiuchi, M. Oshima, S. Takagi, M.
Matsuo, R. Sato, K. Aoki, S. Orimo, “Multi-phonon excitations in Fe2p RIXS on Mg2FeH6K.”, J.
Phys. Soc. Jpn. 84 (2015) 043201.

20.

K. Ozeki, D. Sekiba, A. Uedono, K. K. Hirakuri, T. Masuzawa, “Effect of incorporation of
deuterium on vacancy-type defects of a-C:H films prepared by plasma CVD”, Appl. Surf. Sci. 330(2015) 142.

40

21.

H. Oikawa, R. Akiyama, K. Kanazawa, S. Kuroda, I. Harayama, K. Nagashima, D. Sekiba, Y.
Ashizawa, A. Tsukamoto, K. Nakagawa, N. Ota, “Deposition and characterization of amorphousaluminum nitride thin films for a gate insulator”, Thin Solid Films 574 (2015) 110.

22.

K. Mase, K. Hiraga, S. Arae, R. Kanemura, Y. Takano, K. Yanase, Y. Ogashiwa, N. Shohata, N.
Kanayama, T. Kakiuchi, S. Ohno, D. Sekiba, K. K. Okudaira, M. Okusawa, M. Tanaka, “Decay
processes of Si2s core holes in Si(111)-7x7 revealed by Si Auger electron Si2s photoelectron
coincidence measurements”, J. Phys. Soc. Jpn. 83 (2014) 094704.

41

5.2

International conferences

1.

M. Ohshima, J. Enmi, M. Tsuji, T. Moriguchi, H. Fukuda, Y. Hashikawa, T. Zeniya, H. Kawashima,
K. Koshino, H. Iida, “The hybrid PET and MR imaging of cerebral hemodynamids in rats withhypoxic-ischemic brain injury”, XIII Turku PET Symposium, Turku PET Center, 24-27 May 2014,
Finland.

2.

J. Enmi, Y. Hashikawa, H. Fukuda, T. Moriguchi, M. Ohshima, K. Koshino, H. Kawashima, T.
Zeniya, M. Tsuji, H. Iida, “In vivo imaging-supported development of an intraluminal suture-based
technique for acute-to-chronic cerebral infarction model in rat”, World Molecular Imaging Congress(WMIC2014), COEX Convention Center, 17-20 September 2014, Soul, Korea.

3.

A. Ozawa, Mass measurement with Rare-RI Ring, Workshop ‘Science and Next Generation
Experiments at FRIB and RIBF’ in 4th Joint Meeting of the APS Division of Nuclear Physics andthe Physical Society of Japan, 7-11 October 2014, Waikoloa, Hawaii, USA.

4.

Y. Abe, Isochronous field study of the Rare-RI Ring, STORI'14 - 9th International Conference on
Nuclear Physics at Storage Rings, 28 September - 3 October 2014, Schloss Rheinfels, St. Goar,
Germany.

5.

H. Tsuchida, K. Nakajima, J. Yokoe, M. Sugiyama, T. Majima, S. Tomita, K. Sasa, Y. Saitoh, K.
Narumi, A. Chiba, K. Yamada, S. Matoba, K. Hirata, H. Shibata, K. Kimura, and A. Itoh, “Wakeeffects on fast-molecular transmission through nanocapillaries”, 26th International Conference on
Atomic Collisions in Solids (ICACS-26), 13-18 July 2014, Debrecen, Hungary.

6.

Y. Shiina, R. Kinoshita, S. Tamura, K. Sasa, S. Ishii and S. Tomita, “Cluster effect on the yield of
secondary electrons produced by single electron excitation”, 26th International Conference on
Atomic Collisions in Solids (ICACS-26), 13-18 July 2014. Debrecen, Hungary.

7.

Y. Satou, K. Sueki, K. Sasa, T. Matsunaka, N. Shibayama, T. Takahashi N. Kinoshita, “Activity
ratios in soil contaminated by the source of different reactor condition in the FDNPP accident”,
European Geosciences Union General Assembly 2014, 27 April - 2 May 2014, Vienna, Austria.

8.

Y. Onda, K. Sueki, K. Sasa, T. Matsunaka, M. Honda, Y. Wakiyama, V. Golosov, A. Konoplev, K.
Namba, T. Takase, “Research project on Niida river basin”, International Symposium on
Interdisciplinary Study on Environmental Transfer of Radionuclides from the Fukushima Daiichi
NPP Accident, 9-10 January 2015, Tsukuba, Japan.

42

9.

T. Matsunaka, K. Sasa, K. Sueki, T. Takahasi, M. Matsumura, Y. Satou, N. Shibayama, J. Kitagawa,N. Kinoshita, H. Matsuzaki, “Depth profiles of 129I and 129I / 127I ratio in soil at the near-field site of
the Fukushima Dai-ichi Nuclear Power Plant”, The 13th International Conference on Accelerator
Mass Spectrometry, 24-29 August 2014, Provence, France.

10.

T. Matsunaka, K.Sasa, K. Sueki, N. Shibayama, T. Takahashi, M. Matsumura, Y. Satou, H.
Matsuzaki, A. Goto, T. Watanabe, N. Tsuchiya, N. Hirano, A. Kizaki, “Study on monitoring of
volcanic activity using 129I / 127I ratios in crater lake and hot spring at Zao volcano, Japan”, The 13th
International Conference on Accelerator Mass Spectrometry, 24-29 August 2014, Provence, France.

11.

K. Sasa, K. Sueki, T. Takahashi, M. Matsumura, T. Matsunaka, Y. Satou, N. Shibayama, N.
Kinoshita, J. Kitagawa, K. Nishihara, H. Matsuzaki, “Distribution of 129I in terrestrial environment
released from the Fukushima Dai-ichi Nuclear Power Plant accident“, The 13th International
Conference on Accelerator Mass Spectrometry, 24-29 August 2014, Provence, France.

12.

K. Sueki, N. Shibayama, Y.Satou, K. Sasa, T. Takahashi, T. Matsunaka, M. Matsumura, H.
Matsuzaki, M. Murakami, R.Yamashita, S.Mahua, H. Takada, Y. Koibuchi, L. Soulichan, O.
Haecong, G. Mouri, T. Oki, “Behavior of Iodine-129 and Radioactive Cesium in Japanese River”,
The 13th International Conference on Accelerator Mass Spectrometry, 24-29 August 2014,
Provence, France.

13.

Y. M. Matsumura, N. Shibayama, T. Matsunaka, K. Sasa, K. Sueki, T. Takahashi, Y. Satou, H.
Matsuzaki, “Successive comparison of the extent of 129I contamination in the sample preparationroom”, The 13th International Conference on Accelerator Mass Spectrometry, 24-29 August 2014,
Provence, France.

14.

Y. Satou, K. Sueki, K. Sasa, T. Matsunaka, , T. Takahashi, N. Shibayama, D. Izumi, N. Kinoshita,
H. Matsuzaki, “Development of Strontium-90 AMS in Japan: Progress report”, The 13th
International Conference on Accelerator Mass Spectrometry, 24-29 August 2014, Provence,France.

15.

K. Sasa, T. Takahashi, K. Sueki, T. Matsunaka, M. Matsumura, Y. Satou, D. Izumi, “The new
6MV AMS system at the University of Tsukuba”, The 13th International Conference on
Accelerator Mass Spectrometry, 24-29 August, 2014, Provence, France.

16.

Xiangdong Ruan, Zhaoming Xiong, Kimikazu Sasa, Hongtao Shen, Yongjing Guan,“Radiocarbon Dating of an Ancinent Tomb in Hepu Country, China”, The 13th International
Conference on Accelerator Mass Spectrometry, 24-29 August 2014, Provence, France.

43

17.

Y.Miyake, H. Matsuzaki, K. Sasa, T. Takahashi, “Measurement of Chlorine-36 in surface soil
around F1NPP accident site”, The 13th International Conference on Accelerator Mass
Spectrometry, 24-29 August 2014, Provence, France.

18.

Y. Satou, K. Sueki, K. Sasa, T. Matsunaka, N. Shibayama, T. Takahashi, N. Kinoshita, “Source
estimation of radioactive materials on the ground at the northwestern area from the Fukushima
Dai-ichi Nuclear Power Plant”, Asia Oceania Geosciences Society 2014, 28 July - 1 August 2014,
Sapporo, Japan.

19.

I. Harayama, K. Nagashima, Y. Hirose, H. Oikawa, R. Akiyama, S. Kuroda, H. Matsuzaki, D.
Sekiba, “ΔE-E telescope ERDA on AlN films with 40 MeV 35Cl7+ beam: Development of gas
ionization chamber placed on ICF152”, 21st International Conference on Ion Beam Analysis,23-28 June 2013, Seattle, USA.

20.

K. Kurita, D. Sekiba, I. Harayama, K. Chito, Y. Harada, H. Kiuchi, C. Sakai, M. Oshima, K.
Sodeyama, Y. Tateyama, R. Sato, M. Matsuo, S. Orimo, “Ultra high resolution Resonant Inelastic
soft X-ray Scattering for Mg2FeH6’’, 8th International Conference on Inelastic X-ray Scattering,
SLAC National Accelerator Laboratory Menlo Park, 11-16 August 2013, California, USA.

44

6.
THESES

Master’s theses
Shunnpi AOYAMA

Magnetic properties of CoxFe3-xO4 (001) thin films prepared byreactive sputtering with dual targets.

Fumiya ARAI
Daiki IZUMIIon surfing RF-carpet gascell for superheavy element mass measurement.

Akari HORIUCHI
Yang LIU
Kazuki SAWAHATA

Development of AMS measuring condition using the PHITS code andmeasurement of cosmogenic nuclides.
Preparation and magnetic properties of Fe oxides nanoparticles fromoval platelet α-FeOOH precursor.
Magnetization control of Kr ion implantation to CoFe2O4 thin films.

Measurement of charge-changing cross-section for proton-rich Si and Ar
isotopes.

Undergraduate’s theses
Eri NOGUCHI
Takahiro TAMURA
Ryohei TOMITA
Masaya WATANABE

Straggling effect in channeling on Si(100) with amorphous metal thin films.
Coincidence detection system of ion and secondary electron in HERDA.
Behavior of dissolved radionuclides and ions in riverine water after FDNPP
accident.
The variation of flux of 129I in Tsukuba region.

45

7.
SYMPOSIA

The 15th Japanese national workshop on surface and interface
ion beam analysis

5-6, December 2014
University of Tsukuba, Tandem Accelerator Complex,
Cooperative Research Building C C305

December, 5 Friday

13:00 - 13:05
Welcome Address
Prof. Eiji Kita
(Research Facility Center for Science and Technology, Univ. of Tsukuba, Vice- Director(TAC section))

Session 1
13:05 - 13:45

Chair：Dr. Kenji Kimura(Invited talk)“Investigating surfaces and interfaces with light ions: MEIS and HIM"
Torgny Gustafsson(Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA)13:45 - 14:15(Invited talk)“Helium Ion Microscopy (HIM) for Imaging, Characterization, and nano-Fabrication for
nano-Device Materials and Structures”
Shinichi Ogawa(NeRI, National Institute of Advanced Industrial Science and Technology (AIST))
14:15 - 14:55(Invited talk)“Studies on Surface Structure using Fast Atom Diffraction (FAD)”
H. Winter, M. Busch, J. Lienemann, E. Meyer, A. Schüller, J. Seifert(Institut für Physik, Humboldt-Universität, Berlin, Germany)

Session 2

Chair：Dr. T. Nakamoto46

15:10 - 15:35(Invited talk)“Ion Beam Guiding with Straight and Curved Insulator Capillaries”
Takao M. Kojima1, Tokihiro Ikeda2, Yasuyuki Kanai1, Vladimir A. Esaulov3 and Yasunori
Yamazaki1(1Atomic Physics Laboratory, RIKEN, 2Nishina Center for Accelerator-Based Science,
RIKEN, 3Institut des Sciences Moléculaires d'Orsay, Universite Paris Sud)
15:35 - 15:55“Formation of SOI structure by ultrahigh-temperature oxygen implantation”
Yasushi Hoshino, Tomohiro Kamikawa, and Jyoji Nakata(Department of Mathematics and Physics, Kanagawa University)
15:55 - 16:15“Shape Elongation of Embedded Zn Nanoparticles in SiO2 by Swift Heavy Ion Irradiation”
H. Amekura1, D. Tsuya1, N. Okubo2, and N. Ishikawa2(1National Institute for Materials Science (NIMS), 2Japan Atomic Energy Agency (JAEA))
16:15 - 16:45(Invited talk)“Sensitivity Increase with Etched Tracks on a SiO2 Waveguide in Palmtop Sensor”
Koichi Awazu, Makoto Fujimaki and Xiaomin Wang
(National Institute of Advanced Industrial Science and Technology (AIST))UTTAC facility introduction and tour
16:55 - 17:20

facility introduction“Scientific strategy of UTTAC (Univ. of Tsukuba, Tandem Accelerator Complex) with new
6 MV tandem accelerator and high-resolution ion beam analysis”
K. Sasa, T. Moriguchi and D. Sekiba(UTTAC, Univ. of Tsukuba)
17: 20 - 18:00

facility tour

December, 6 Saturday

Session 3
9:00 - 9:25

Chair：Dr. Shigeo Tomita(Invited talk)47

“Proton Irradiation in Liquid with Glass Capillaries and Metallic Particle Formation by
Radiation Reduction”
T.Kobayashi1, T. Yamaki2, T. Hakoda2, S. Yamamoto2 and Y. Yamazaki1(1RIKEN, 2JAEA)
9:25 - 9:45
“Liquid-surface structural analysis by MeV ion microbeams through capillaries”
S. Nomura1, K. Miyahara1, R. Furuya1, J. Wang1, T. Majima1,2, M. Imai2,
H. Tsuchida1,2, and A. Itoh1,2(1Department of Nuclear Engineering, Kyoto University, 2Quantum Science andEngineering Center, Kyoto University)
9:45 - 10:05“Irradiation of liquid droplets with MEV-energy ions in vacuum”
K. Kitajima1, T. Majima2, Y. Oonishi1, H. Ueda1, H. Tsuchida2, and A. Itoh1,2(1Department of Nuclear Engineering, Kyoto University, 2Quantum Science andEngineering Center, Kyoto University)
10:05 - 10:25“Solid-Liquid Interface Analysis with MeV-energy Heavy Ion Beams”
Toshio Seki1,4, Makiko Fujii2, Shunichiro Nakagawa1, Takaaki Aoki3,4, andJiro Matsuo2,4(1Department of Nuclear Engineering, Kyoto University, 2Quantum Science andEngineering Center, Kyoto University, 3Department of Electronic Science and Engineering,
Kyoto University, 4CREST, Japan Science and Technology Agency (JST))

Session 4
10:35 - 11:05

Chair：Dr. Hiroshi Kudo
(Invited talk)“Secondary Electron Emission from Thin Carbon Foils by Ion Beam Penetration”
Hidemi Ogawa1, Kunikazu Ishii1, Toshiaki Kaneko2(1Department of Physics, Nara Women’s University, 2Graduate School of Science,
Okayama University of Science)
11:05 - 11:25“Vicinage Effect on Secondary-Electron Emissions from Carbon Foils Bombarded with
62.5-keV/u Cn+ Ions”
K. Narumi, A. Chiba, K. Yamada, S. Matoba, Y. Saitoh

48

(Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency)
11:25 - 11:45“Forward Secondary Electron Emission from Carbon Foil induced by Swift single ion anddi-atom cluster ion”
Toshiaki Kaneko1, Ryo Tanaka1, Fuyuhito Miyahara1, Hidemi Ogawa2(1Graduated School of Science, Okayama University of Science, 2Graduate School of Hum.
and Sci., Nara Women’s University)
11:45 - 12:05“Field Ion Microscope Observation of Organic Molecules on Tungsten Surface”
Yasuhito Gotoh, Susumu Hogyoku, and Hiroshi Tsuji(Department of Electronic Science and Engineering, Kyoto University)

Session 5
12:45 - 13:15

Chair：Dr. Takanori Koshikawa(Invited talk)“Transmission secondary ions mass spectrometry of an amino acid using 5 MeV C60 ions”
K. Nakajima1, K. Nagano1, M. Suzuki1, K. Narumi2, Y. Saitoh2, K. Hirata3, and K. Kimura1(1Department of Micro Engineering, Kyoto University, 2Takasaki Advanced Radiation
Research Institute, JAEA, 3National Metrology Institute of Japan, AIST)
13:15 - 13:35“Enhancement of secondary ion emission from solid hydrogen films at cryogenic
temperature”
Taku Suzuki(National Institute for Materials Science)
13:35 - 13:55“Determination of Potential Gradient near and Space Charge Potential at the Interface
between Electrolyte and Electrode of Li Ion Battery by Means of ERD-RBS Techniques”
Kenji MORITA1, Bun TSUCHIYA2, Takehisa KATO3, Yasutoshi IRIYAMA3, Hideji
TSUCHIDA4, Takuya MAJIMA4(1Nagoya Industrial Science Research Institute, 2Meijo University, 3Nagoya University,
4

Kyoto University)

Session 6

Chair：Dr. Daiichiro Sekiba

14:05 - 14:25

49

“Study of hydrogen depth distributions by resonant nuclear reaction analysis toward theclarification of the reliability degradation of semiconductor devices”
Riichiro Takaishi1, Yusuke Higashi1, Masamichi Suzuki1, Yuichiro Mitani1, Mitsuhiro
Tomita1, Masuaki Matsumoto2, Shohei Ogura2, andKatsuyuki Fukutani2(1Corporate R&D Center, Toshiba Corporation, 2Institute of Industrial Science, Universityof Tokyo)
14:25 - 14:45“Temperature dependence of ESD rate from KBr(001) surface measured by fast proton
scattering technique”
Y. Fukazawa and Y. Susuki(Division of Science Education, Osaka Kyoiku University)
14:45 - 15:05“Real-time observation of thermal relaxation of ion damage by synchronized positron probe
analysis”
H. Tsuchida1,2, S. Mizuno1, H. Tsutsumi1, A. Kinomura3, R. Suzuki3 and
A. Itoh1,2(1Department of Nuclear Engineering, Kyoto University, 2Quantum Science andEngineering Center, Kyoto University, 3National Institute of Advanced Industrial Scienceand Technology (AIST))

50The 17th Japanese Symposium on Accelerator Mass
Spectrometry
Date: March 2－3 (Mon.－Thu.), 2015
Place: University Hall, University of Tsukuba
Host Organization：Tandem Accelerator Complex, University of Tsukuba
The Japan Society for AMS Research

Program
2 March 2015
Opening Remarks

T. Nakamura (Nagoya University)

Session 1: Status report and development 1(Chair: K. Sasa, H. Matsumura)
1－1

Status and Application of AMS System at Nagoya University (2014) : T. Nakamura(Nagoya University)

1－2

Installation of compact AMS to the University of Tokyo : M. Yoneda (The University ofTokyo)

1－3

Development of 236U-AMS – Identification of interference components : K. Nakashoji(The University of Tokyo)

1－4

Development of 36Cl-AMS using the PHITS code and measurement of cosmogenic
nuclides : D. Izumi (University of Tsukuba)

1－5

Development of GC-AMS system and performance of automatic sample preparation
system for 14C-AMS at the University of Tsukuba : T. Matsunaka (University of Tsukuba)

Session 2: Application 1(Chair: A. Sakaguchi)
2－1

The variation of 129I deposition in Tsukuba region : M. Watanabe (University of Tsukuba)

2－2

Behavior of dissolved radionuclides and ions in riverine water after the FDNPP accident :R. Tomita (University of Tsukuba)

2－3

Study of iodine dynamics in soil by analysis of 129I/127I ratio : W. Kijima (The Universityof Tokyo)

51

2－4

The speciation analysis for iodine in seawater : E. Tanaka (The University of Tokyo)

2－5Comparison of 129I/127I ratio between marine fishes and seawater : H. Kusuno (The
University of Tokyo)

Session 3: Application 2(Chair: K. Sueki)
3－1

Establishment of the estimation method of the date of birth by using tooth enamel, root
organic and inorganic matter of Japanese : K. Kunita (Nagoya University)

3－2

High precision radiocarbon dating of charred materials using ABOx-SC treatment
S. Tomiyama (Nagoya University)

3－3

Rapid change of sedimentation rate from Lake Baikal sediment core corresponding withthe global climate warming
F.W. Nara (Tohoku University)

3－4

Geochronology and geochemistry of past tsunami sediments
T. Watanabe (Tohoku University)

Special lecture 1(Chair: T. Nakamura)
S－1

Introduction of KIGAM AMS Lab. and Related Facilities
W. Hong (KIGAM)

Poster Session
P－1

An attempt on 14C dating of a cremated bone
H. Mukumoto (Nagoya University)

P－2

Design of the negative ion cooler
Y. Miyake (The University of Tokyo)

P－3

Development of degradation method of radionuclide in soil using pressure vessel
M. Honda (University of Tsukuba)

P－4

Determination of ultra-low 129I and 99Tc in soil samples by Triple Quadrupole ICP-MS
M. Honda (University of Tsukuba)

52

P－5

14

P－6

Temporal changes in volcanic activity and iodine isotopic ratio at Zao volcano
T. Matsunaka (University of Tsukuba)

P－7

Basic knowledge for development of 90Sr-AMS
Y. Satou (University of Tsukuba)

P－8

Current Status of System Technology in the JAEA-AMS-TONO (2014)
A. Matsubara (JAEA)

P－9

Continuous research of 129I contamination in the chemical sample preparation room forAMS
M. Matsumura (University of Tsukuba)

P－10

Possibility of radiocarbon dating to bronze implement and application to a bronze bellcalled Dojoji Kanemeki Doutaku
H. Oda (Nagoya University)

P－11

236

C age at the early Sporer minimum of tree-ring from the northern Japan
M. Hakozaki (Nagoya University)

U in the pan-Japan Sea area
A. Sakaguchi (University of Tsukuba)

3 March 2015
Session 4: Status report and development 2(Chair: T. Matsunaka, A. Matsubara)
4－1

Present status of the JAEA-AMS-TONO (2014)
Y. Saito-Kokubu (JAEA)

4－2

Status report of MALT, The University of Tokyo
H. Matsuzaki (The University of Tokyo)

4－3

Installation Status and Future Prospects of the 6 MV AMS system at the University ofTsukuba
K. Sasa (University of Tsukuba)

4－4Current status of the Compact AMS system at Paleo Lab Co., Ltd. (2014)
M. Sato (Paleo Labo Co., Ltd.)

4－5

Status report of Single Stage AMS at Atmosphere and Ocean Research Institute, The
University of Tokyo53

Y. Miyairi (The University of Tokyo)

Special lecture 2(Chair: K. Sasa)
S－2

The Contribution of AMS to the Study of West Asian Archaeology
A. Tsuneki (University of Tsukuba)Special lecture 3(Chair: H. Matsuzaki)
S－3

The Installation of the 6 MV tandem AMS/IBA accelerator recently installed at Tsukuba
University
M.V. Mores (NEC)Session 5: Application 3(Chair: T. Watanabe, M. Hakozaki)
5－1

Temporal change in bomb-produced radiocarbon in the North Pacific in the past two
decades derived from repeat hydrography
Y. Kumamoto (JAMSTEC)

5－2

Contribution of Dead carbon source to fluctuate DI14C in Lake Biwa water
Y. Miyata (Kanazawa University)

5－3

RICE-W (Radiocarbon Intercomparison on Chemical Experiments, Water series)
program-An interim reportH.A. Takahashi (AIST)

5－4

The indirect radiocarbon dating using microscope observation and bibliographicalconsideration of calligraphy
H. Oda (Nagoya University)

5－5

Distribution of 129I in the Arctic and North Pacific Ocean
H. Nagai (Nihon University)

Closing Remarks

K. Sasa (University of Tsukuba)

Facility tour (6 MV AMS system, Sample preparation room)

54

8.
LIST OF PERSONNEL

Tandem Accelerator Complex
E. Kita

Director, Professor

K. Sasa

Associate Professor

D. Sekiba

Lecturer

T. Moriguchi

Assistant Professor

H. Oshima

Electrical Engineer

Y. Tajima

Mechanical Engineer

S. Ishii

Mechanical Engineer

T. Takahashi

Electrical Engineer

Y. YamatoElectrical Engineer

T. Matsunaka

Research Fellow

M. Matsumura

Research Supporter

M. Ohyama

Administrative Staff

N. YamadaAdministrative Staff

H. Muromachi

Administrative Staff

Research Members1
Inst. of Physics
I. Arai

K. Sasa

D. Nagae

A.Ozawa

K. Akimoto

S. Selvakumar

E. Kita

M. Minagawa

D. Sekiba

T. Suemasu

S. Tomita

A. Uedono

H. Yanagihara

Y. Watahiki

Inst. of Applied Physics

Inst. of Materials Science
T. Kondo

M. Takahashi

Inst. of Geoscience
M. Kurosawa
Inst. of Chemistry
K. Sueki

A. Sakaguchi

Staff of Open Advanced Facilities Initiative
1

The “research members” include the authors and coauthors within 5 years back from this fiscal year, as well as themembers of research projects running at UTTAC.

55

H. Kudo

H. Naramoto

M. Sataka

A. Yamazaki

H. Muromachi
Graduate students
Doctoral Programs of Pure and Applied Science
Y. AbeS. Fukuoka

I. Harayama

Y. Ishibashi

K. Kurita

S. Kimura

M. MukaiM. Honda

Y. Satou
Master’s Programs of Pure and Applied Science
F. Arai

H. Alima

R. Aoyama

A. Horiuchi

D. Izumi

Y. Ichikawa

Y. LiuS. Maeda

T. Tamura

R. Tomita

M. Watanabe

K. Sawahata
Undergraduates
E. Noguchi

Scientific Gutests and Fellows
K. Awazu

National Institute of Advanced Industrial Science and Technology (AIST)

M. Fujimaki

National Institute of Advanced Industrial Science and Technology (AIST)

Y. Tosaki

National Institute of Advanced Industrial Science and Technology (AIST)

T. Hayakawa

Japan Atomic Energy Agency (JAEA)

T. Shizuma

Japan Atomic Energy Agency (JAEA)

S. KubonoCenter for Nuclear Study, the University of Tokyo (CNS)

A. SatoOsaka University

A. Yamamoto

High Energy Accelerator Research Organization (KEK)

T. AdachiHigh Energy Accelerator Research Organization (KEK)

M. YoshidaHigh Energy Accelerator Research Organization (KEK)

N. Kawamura

High Energy Accelerator Research Organization (KEK)K. Shimomura

High Energy Accelerator Research Organization (KEK)

P. Strasser

High Energy Accelerator Research Organization (KEK)

T. Nakamoto

High Energy Accelerator Research Organization (KEK)

M. IioHigh Energy Accelerator Research Organization (KEK)K. YoshimuraHigh Energy Accelerator Research Organization (KEK)

H. Matsumura

High Energy Accelerator Research Organization (KEK)

N. Kinoshita

SHIMIZU Corporation

56