UTTAC-87, 2018UTTAC
ANNUAL REPORT 2017

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

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

UTTACANNUAL REPORT 2017
April 1, 2017 – March 31, 2018

UTTAC-87, 2018

Editors : Tetsuaki Moriguchi, Kimikazu Sasa, Yoshihiro Yamato, Masumi Matsumura,
Masao Sataka, Hiroshi Naramoto, and Hiroshi Kudo (editor-in-chief)

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 © 2017 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 researches carried out at University of Tsukuba Tandem
Accelerator Complex (UTTAC) during the fiscal year 2017 (1 April 2017 ~ 31 March2018). The topics include not only accelerator-based researches using the 6MV Pelletronand 1MV Tandetron accelerators, but also radioisotope-based researches including
positron annihilation spectroscopy and Mössbauer spectroscopy.
August 1, 2018
Editorial board-i-

EDITORIAL: Research results and the facility’s publication list
In the early period of UTTAC, the publication list in its annual report was certainly the outcome of the
facility. After about 40 years since then, the research field at UTTAC has expanded entirely towards appliedstudies such as accelerator mass spectrometry, ion beam analysis and modification of materials, radiation
tolerance test of electronic devices, etc. Reflecting such circumstances, for many users the experimental
data taken at UTTAC is necessary but not enough. In actual, they usually proceed with research using otherfacilities in parallel. It follows that the equivalence of the user’s research results and the facility’s outcome,mentioned above, has become unclear. It is the publication list of this Annual Report that tells such a trend
clearly. Here at UTTAC, while there is a certain number of direct outcome, we see a remarkable increase of
the research results that are generated indirectly or supportively.
July 31, 2018
Editorial board- ii -

CONTENTS

1. ACCELERATOR AND RELATED FACILITIES
1.1
1.2
1.3

Accelerator operation 2017 ················································································

1

4

Measurement of the polarization of the polarized proton beam via the p- He elastic
scattering reaction···························································································

3

Charge state distribution of ions accelerated by the 6MV tandem accelerator at UTTAC··········

5

2. NUCLEAR AND ATOMIC PHYSICS
2.1 Production of polarized unstable nuclei by using polarized proton beams···························

7

2.2 Development of a position-sensitive detector using scintillating fibers······························

9

2.3 Measurements for nitric acid produced by proton beam irradiation in a humidified air············ 11

3. ACCELERATOR MASS SPECTROMETRY
3.1

Operational status of the Tsukuba 6 MV multi-nuclide AMS system in fiscal 2017················

13

3.2

Temporal variation of 36Cl in monthly precipitation at Tsukuba before and after the
FDNPP accident····························································································

15

3.3

36

Cl record in the Antarctic ice core around the cosmic-ray event of 5480 BC studied
with 36Cl AMS ···························································································

17

36

Depth profile of Cl in the soil at Fukushima after the Fukushima Daiichi Nuclear Power
Plant accident ····························································································

19

3.5

Anthropogenic iodine-129 in the Japan Sea Bottom Water in 2017 ································

21

3.6

Development of the prompt and sensitive determination method for strontium-90 withaccelerator mass spectrometry ···········································································

23

Trial of determination of 41Ca in stony meteorites by accelerator mass spectrometry ···········

25

3.4

3.7

4. BEAM AND ISOTOPE APPLICATIONS
4.1

Carrier trapping by vacancy-type defects in Mg-implanted GaN studied using
monoenergetic positron beams ·········································································

27

Two-dimensional mapping of hydrogen and other elements with microbeam-basedtransmission ERDA and PIXE··········································································

29

Production of 16 channel preamplifier module and development of high-sensitivity
HERDA equipped with strip SSD······································································

31

4.4

Location of hydrogen in Mg/H-coimplanted GaN by RBS/ERDA and channeling NRA······

33

4.5

Present status of TOF-E telescope ERDA system development····································

35

4.2
4.3

- iii -

Experimental verification of a gain reduction model for the space charge effect in awire chamber······························································································

37

Quantitative micro-PIXE analyses of trace elements in sphalerite from hydrothermallyaltered sediments··························································································

39

Preliminary report on micro-PIXE analysis of trace Ni in single fluid inclusions from amiarolitic quartz at Tsushima granite··································································

41

Physico-chemical properties of active layers controlling the boric acid rejection bypolyamide composite reverse osmosis and nanofiltration membranes····························

43

4.10 Thermoelectric SiGe film synthesized on a flexible plastic substrate·····························

45

4.11 Development of T-ERDA method for sensitive hydrogen-profiling·······························

47

4.12 Epitaxial strain-induced enhancement of low-temperature topotactic hydrogen substitution
reaction of SrTiO3························································································

49

4.13 Room and helium temperature Mössbauer experiments on Co-Ni ferrites toassess effect of synthesis method on magnetic properties···········································

51

4.14 Mössbauer spectroscopy study of spinel structured MnxFe2O4-δ particles under
external magnetic field···················································································

53

4.15 Magnetic properties of individual magnetite nanoparticles·········································

55

4.6
4.7
4.8
4.9

5. BEAM IRRADIATION EFFECT
5.1

Construction of efficient radiation experiment system···············································

57

5.2

Comparison of LET versus SEU cross section curves for irradiation withenergetic ions and with pulsed laser·····································································

59

6. LIST OF PUBLICATIONS AND PRESENTATIONS
6.1

Journals ····································································································

61

6.2

Reviews and books························································································

67

6.3

Poster or oral presentations at academic meetings····················································

67

6.4

UTTAC seminars·························································································

79

7. THESES··········································································································
8. LIST OF PERSONNEL·····················································································

81- iv -

83

1.
ACCELERATOR AND RELATED FACILITIES1.1

Accelerator operation 2017

K. Sasa, S. Ishii, H. Oshima, Y. Tajima, T. Takahashi, Y. Yamato, T. Moriguchi, A. Uedono
1 MV Tandetron accelerator
The operating time and the experimental beam time of the 1 MV Tandetron accelerator were 628.3 and300.7 hours, respectively, during the total service time in FY 2017. The total number of 59 days was used
for beam experiments. A total of 244 researchers and students used Tandetron in FY 2017. Figures 1 and 2
show classification of the accelerated ions and of the experimental purposes, respectively. Notably, 13.9%of the accelerator machine time was used by external users for materials analysis with RBS/ERDA.

35Cl

15.9%

1H

26.6%

Education
5.5%

Developments(Instruments
andDetectors)
24.2%

16O

RBS/ERDA
49.6%

25.2%
NRA
1.6%

4He

32.3%
PIXE
19.1%

Fig. 2. Purpose of use of the 1 MV
Tandetron accelerator in FY 2017.

Fig. 1. Accelerated ions by the 1 MV Tandetron
accelerator in FY 2017.

6 MV Pelletron tandem accelerator
The operating time and the experimental beam time of the 6 MV Pelletron tandem accelerator were1857 and 1501 hours, respectively, in FY 2017. The number of days the accelerator was in operation was
154. As a result, 90 research programs were carried out and a total of 636 researchers used the accelerator.
Figure 3 shows the beam time histogram with respect to the terminal voltage. Figures 4 and 5 showclassification of the accelerated ions and of the experimental purposes, respectively. The operating time at
the terminal voltage of 6 MV was 52.2% of the total beam time. The AMS experiment occupied thelongest beam time, 47.3% of the total. This was followed by the microbeam experiments, 21.6% of thetotal, for study of structural materials in the Strategic Innovation Promotion Program: SIP.
There was no major trouble for routine beam delivery and experiments in 2017. However, the foilchanger in the accelerator terminal caused malfunctioning in circulating the carbon foil unit, as was thesame case as in 2016 [1]. We opened the accelerator tank and repaired the foil changer in March 2018. A
stripper gas valve in the accelerator terminal was also replaced with new one at the same time. As for the
rest of maintenances, we repaired the beam attenuator on the low energy side.

1

Terminal voltage (MV)

6
5
4
3
2
1
0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

Beam Time (hours)

Fig. 3. Beam time histogram as a function of the terminal
voltage for the 6 MV Pelletron tandem accelerator in FY 2017.

Au
0.1%

Br
0.3%
Ni
0.4%

Sr
5.5%

Developments(Instruments andDetectors) 1.0%

W
0.1%

I
8.3%

Cosmic ray
experiments
2.7%

H
19.9%

Ca
4.2%

N
7.9%

Si
0.9%

F
0.1%

Beam test
0.7%

Radiation
Resistance Test
8.5%
Nuclearphysics
6.8%

He
9.6%

Cl
36.0%

Education
2.1%

AMS
47.3%

Li
1.5%
B
1.4%

Microbeam
21.6%

C
0.3%

O
3.5%

IBA
（RBS/ERDA/NRA/PIXE)
9.2%

Fig. 5. Purpose of use of the 6 MV Pelletron
tandem accelerator in FY 2017.

Fig. 4. Accelerated ions by the 6 MV
Pelletron tandem accelerator in FY 2017.

Reference[1] K. Sasa et al., UTTAC ANNUAL REPORT 2016, UTTAC-86 (2017) 1.

2

1.2

Measurement of the polarization of the polarized proton beam via
the p -4 He elastic scattering reaction

T. Moriguchi, M. Amano, Y. Yamato, A. Ozawa, S. Suzuki, D. Kamioka, D. Nagae1
The Lamb-shift polarized ion source (PIS) was installed at UTTAC in 1976 for experimental nuclear
physics [1]. PIS was damaged seriously by the Great East Japan Earthquake, but the decision was made toreconstruct PIS as one of the ion sources for the newly designed 6 MV tandem accelerator. Following thereconstruction of PIS, we attempted to generate the polarized beams and confirmed the resonance peaks
which correspond to polarized proton and deuteron beams [2]. In FY2017, we measured the polarizationof a polarized proton beam downstream of the 6 MV tandem accelerator with a polarimeter using thep-4 He elastic scattering reaction.
The polarized proton beam from PIS was accelerated to 12 MeV and transported to the A6 course.
The spin quantization axis was set to be perpendicular to the horizontal plane. The direction of the spin
(spin-up or spin-down) could be selected by reversing the direction of the magnetic field of the spin filter,
which is the main component of PIS for the generation of polarized beams. Figure 1 shows the schematiccross section of the polarimeter used in the present measurement [3], which is viewed along the directionof the spin quantization axis of the polarized beam. The inside of the polarimeter was filled with 4 He gasof approximately 0.1 MPa. Elastically scattered protons in the polarimeter traveled through the intervalsof each vane and were detected by silicon detectors at both sides. We connected this polarimeter to theend of the A6 course. Polarization P is expressed as
A·P =NL − NR
NL + NR(1)

where A is the analyzing power; NL and NR are the number of elastically scattered protons detected by thesilicon detectors on the left and right sides of the polarimeter, respectively. In this case, A is approximately
equal to one [4]. Figure 2 shows the experimental results obtained from the two silicon detectors. The
main peaks shown in Fig. 2 correspond to the energy of the elastically scattered protons. In the caseof spin-up (spin-down), the number of the protons scattered to the left (right) side is larger than that tothe other side, as shown in Fig. 2. From this experimental result and using Eq. (1), we found that thepolarization at the end of the beam course was approximately 44% for the spin-up case and 36% for the
spin-down case. These polarizations are lower than that of downstream of the PIS (approximately 80%)
obtained using the quenching method [2]. One of the reasons for this depolarization may be the electron
exchange between ions and a residual gas inside the beam duct in the accelerator. In order to suppress
the depolarization, we used a thin carbon foil (approximately ten µg/cm2 ) as the electron stripper withoutargon gas in the gas stripper canal. However, owing to possible defects in the gas valve or vacuum system,
argon gas might have leaked slightly into the canal. This would increase the depolarization. We are now
attempting to improve the polarization of the polarized proton beam.

1 RIKEN, Nishina Center3

Fig. 1. Schematic cross section of the polarimeter with labels: 1. Harver foils, 2. vanes, 3. diaphragms, 4.
silicon detectors, and 5. O-ring [3].

(a)

(b)
1200

Left
Right

800

Yield

Yield

1000
600
400
200
0
0

100 200 300 400 500 600 700 800
Energy (ch)

1600
1400
1200
1000
800
600
400
200
0

Left
Right

0

100 200 300 400 500 600 700 800
Energy (ch)Fig. 2. Energy spectra obtained from silicon detectors at the left (red line) and the right (blue line) sidesof the polarimeter. Shown in (a) and (b) are the results for spin-up and spin-down, respectively.

References[1] Y. Tagishi et al., Nucl. Instrum. Methods 164 (1979) 411.
[2] T. Moriguchi et al., UTTAC Annual Report 2016, UTTAC-8 (2017) 5.
[3] A. Kurashima et al., UTTAC Annual Report 1987, UTTAC-54 (1988) 14.
[4] P. W. Keaton, Jr. et al., Phys. Rev. Lett. 29 (1972) 880.

4

1.3

Charge state distribution of ions accelerated by the 6MV tandem
accelerator at UTTAC

M. Sataka, T. Takahashi, H. Naramoto, H. Kudo, K. Sasa
Ion acceleration tests with the 6MV tandem accelerator have been continued from the previous fiscal
year [1]. Since we have only about 2 year experience of the accelerator operation, there is still a lack oftechnical data required when an experiment at UTTAC is planned. Such data are of practical importanceespecially for external users who collect data for wide range of experimental parameters by utilizing several
accelerator facilities. One of the examples is the study of radiation tolerance of electronic devices used inspace [2].
We have measured beam currents of accelerated ions at the terminal voltages of 1, 3 and 6 MV as afunction of ion charge state, employing Ar gas as the charge stripper. We also examined the foil stripper forseveral ion species. Both of the strippers were set and used under the conditions to obtain the most effective
beam transport. The ions tested were Li, B, C, F, Si, Br and W. For the ions heavier than Br, fluctuation of
the terminal voltage by electron loading could be suppressed by tightening the entrance slit. This allowed tostabilize the terminal voltage by reducing the ion beam current only by ~10%.
Figure 1 shows the beam current vs. charge state of silicon ions measured for the terminal voltage of
6MV using the gas and foil strippers. The distribution of beam current shifts to the higher charge state by
2−3 for use of the foil stripper than for the gas stripper. The practical maximum energy for Si obtained is 66
MeV for Si10+ when using the foil stripper, and 60 MeV for Si9+ when using the gas stripper. The mostprobable charge state of Si is found to be increased by ~3 for the foil stripper (7+ state) compared with thegas stripper (4+ state). For Br, the corresponding increase is found to be ~6.
1000
foil

Beam Current (nA)

gas
100

10

1

0.1
1

2

3

4

5

6

7

8

9

10

11

Ion Charge State
Fig. 1. Beam current vs. charge state of silicon ions measured for the terminal voltage of 6 MV.

5Table 1 shows the summary of the acceleration tests of ion species in 2016 and 2017. For a given ion
species, the charge states and energies of ion beams obtainable from the 6MV tandem accelerator are shownby the circular and triangular symbols. Other beam conditions with no symbols in Table 1 are not realized
at UTTAC. For ion beams available at UTTAC, the maximum energy covered by the 6MV tandem
accelerator is 90 MeV.
Table 1. Test results of acceleration of ion species at the terminal voltage of 6 MV in 2016 and 2017.
The measured beam intensity is shown by the symbols:≥ 1nA and : ≤1nA. Shown in red are the dataobtained for foil strippers.
Charge Energy
State （MeV）
14
90
13
84
12
78
11
72
10
66
9
60
8
54
7
48
6
42
5
36
4
30
3
24
2
18
1
12

He

◯
◯

Li

◯
◯
◯

B

△
◯
◯
◯
◯

C

◯
◯
◯
◯
◯

O

◯
◯
◯
◯
◯
◯
◯

F

◯
◯
◯
◯
◯
◯
◯
◯

Ion Species
Si
Cl

Ni

◯
◯
◯
◯
◯
◯
◯
◯

△
◯
◯
◯
◯
◯
◯
◯
◯
◯

◯
◯
◯
◯
◯
◯
◯

References[1] M. Sataka et al., UTTAC Annual Report 2016, UTTAC-86 (2017) 9.
[2] Y. Tsuchiya et al., §5.2 of this UTTAC Annual Report 2017 (2018).

6

Br
△
◯
◯
◯
◯
◯
◯
◯
◯
◯
◯

Ag
△
△
◯
◯
◯
◯
◯
◯
◯
◯

I
◯
◯
◯
◯
◯
◯
◯
◯

W

△
△
◯
◯

Au
△
△
◯
◯
◯
◯
◯

2.
NUCLEAR AND ATOMIC PHYSICS

2.1 Production of polarized unstable nuclei by using polarized proton beams
A. Ozawa, T. Moriguchi, Y. Yamato, M. Amano, D. Kamioka, S. Suzuki
We are attempting to produce polarized unstable nuclei byusing polarized proton beams in the aim of measuring nuclear
moments of unstable nuclei. Until FY2016, we have tried to
produce unstable nuclei by target material including Mg and
Si in 1 MV tandetron and 6 MV tandem accelerator [1].
In FY2017 we performed an experiment using polarized
proton beams to check our nuclear magnetic resonance(NMR) system associated with beta-rays (beta-NMR system).
Schematic view of our beta-NMR system is shown in Fig. 1.
Polarized proton beams irradiate the target material. Beta-rays

Fig. 1 Beta-NMR system. The systememitted from the produced unstable nuclei are detected by consists of a magnet (H0), a LC resonancescintillation counters located up and down of the target circuit, which provides RF with ω, andmaterial. To perform NMR, the static magnetic field (H0) and beta-ray detectors.

the radio-frequency (RF) magnetic field which is perpendicular to H0 are applied to the target material. To
check the performance of our beta-NMR system, we tested a Si target with Ep = 12 MeV. We applied ~1.8 kG
for H0. In the previous measurement [2], polarized 29P and 25Al nuclei were produced and the magnetic
moment of 25Al was successfully measured. In the present work, the polarized proton beams accelerated to
12 MeV by the 6 MV tandem accelerator
irradiated a 0.5 mm thick Si target placed inour beta-NMR system. Proton polarization
degree in the ion source was about 70%.
Figure 2 shows the time spectrum ofbeta-rays observed after irradiation of thepolarized proton beams (about 20 nA beam
intensity) for 10 seconds. The fitting results
assuming half-lives of 29P (T1/2 = 4.2 s), 25Al
(T1/2 = 7.2 s) and 30P (T1/2 = 150 s) are shownby a solid line in Fig. 2. In this measurement,
Fig. 2. Time spectrum of beta-rays in 12 MeV proton beamwith a Si target. The solid line is the fitting result assuming
half-lives of 29P, 25Al and 30P.

we observed beta-ray asymmetry of up anddown ratio deduced from the counts
measured by the up and down beta-ray
detectors. The symmetry is proportional tonuclear polarization degree created in the unstable nuclei. Presently the deduced asymmetry is 0.769(1) %,which is almost consistent with the observed asymmetry in the previous measurement [3]. Thus, production
and detection of the nuclear polarization have been confirmed in our beta-NMR system. In the next step, we

7

will apply NMR to the polarized nuclei and confirm the magnetic moments of 25Al and 29P. The magnetic
moment of 29P will be compared with the published data [3].
References[1] A. Ozawa et al., UTTAC Annual Report 2016 (2017) 11.
[2] T. Minamisono et al, Phys. Rev. C 14 (1976) 376.
[3] K. Sugimoto et al., in Hyperfine Interactions in Excited Nuclei, edited by G. Goldring and R. Kalish(Gordon and Breach, New York, 1971), p. 325.

8

2.2

Development of a position-sensitive detector using scintillating fibers

T. Yamaguchi1,2 , K. Wakayama2 , K. Nishimuro2 , T. Kobayashi2 , T. Moriguchi, A. Ozawa, S. Suzuki
We are developing a novel simple position readout method for a plastic scintillation counter for
the Rare-RI Ring facility at the RI Beam Factory (RIBF) [1]. In high-energy RI beam facilities, wellestablished gas position-sensitive detectors, such as parallel plate avalanche counters (PPAC) [2], are used
for beam diagnostics. As the Rare-RI Ring facility has many focal planes in an approximately 160-mlong injection beam line, numerous detectors are required for beam diagnostics. However, the operationand maintenance of such detectors can be expensive and often time-consuming. Thus, simple operation
without complicated gas handling and expensive detectors is desired.
In the present study, we performed proof-of-principle experiments for a prototype detector. The prototype uses thin plastic scintillator bars and multi-pixel photon counters (MPPCs) for the scintillation lightreadout. This can also be used as a versatile diagnostics tool for small-intensity beams. We performed
the detector test experiments3 at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility [3] and at
UTTAC. Using different beam species and energies, the detector performance was studied systematically.
The present prototype detector consists of 20 plastic scintillator bars (Eljen Technology EJ-200, 3 ×
3 × 100 mm3 ) arranged to form a flat plane. Each end of the scintillator bars was connected to a common
light guide bar (3 × 3 × 120 mm3 ). The scintillation photons were read out by 4 MPPCs (Hamamatsu
S12572-100C) through the light guides. The beam position can be obtained from the timing and charge
differences of the scintillation light pulses propagated from each end of the light guide bars.
(b)y (mm)y (mm)(a)x (mm)x (mm)

Fig. 1. Comparison of the two-dimensional beam profiles obtained (a) from PPAC, and (b) from theprototype detector (using the pulse timing differences). Certain beam spots are divided into two parts,
because the particles passing through a hole hit two plastic scintillator bars [4].

A test experiment was carried out at HIMAC using a 200-MeV/nucleon 84 Kr beam. Two PPACs wereused as references to calibrate the positions. We successfully obtained the beam position distributions
1 Cross appointment
2 Department of Physics, Saitama University
3 condensed from the proceedings of the International Conference on Nuclear Physics at Storage Rings (STORI’17) [4]9from the prototype. The position resolution was 2–3 mm in σ , and the detection efficiency was close to100%. A measurement was also carried out using a collimator to verify the resolutions. The collimator
had holes of diameter 2 mm at intervals of 10 mm in the x- and y-directions. Figure 1 shows the typicalbeam profiles obtained (a) from PPAC, and (b) from the prototype detector. The collimated beam spots
are separated well. In Fig. 1 (b), several beam spots are divided into two parts. This is because the ionsthat passed through a single hole hit two plastic scintillator bars.
At UTTAC, a 12-MeV proton beam from the 6MV tandem accelerator was used to test the response
to a small energy deposit. The beam was irradiated onto a 2.5-µ m-thick Au foil placed at the target
chamber of the A7 course. The protons scattered at 30◦ were directed to the prototype detector. A position
correlation is successfully observed as shown in Fig. 2, where the plotted ratios, Qx ratio and Qy ratio ,are sensitive to the x- and y-positions, respectively. In detail, they are calculated from the pulse height
integrated values;

Qx ratio =

up

up

up

up

down
Qleft − Qright + Qdown
left − Qrightdown
Qleft + Qright + Qdown
left + Qright,

Qy ratio =

up

up

up

up

down
Qleft − Qdown
left + Qright − Qrightdown
Qleft + Qdown
left + Qright + Qright,(1)

where the combinations of left, right, up, and down indicate the positions of MPPCs placed at the four
corners of the detector. However, the resolution should still be improved. Notably, a series of developments performed at UTTAC and HIMAC facilities resolved the previously observed non-linear response
between the positions and the pulse differences of the detector. Further developments are ongoing.

Fig. 2. Typical position correlation observed for the proton beam. Qx ratio and Qy ratio are given by eq. (1).

References[1] A. Ozawa et al., Prog. Theo. Exp. Phys. 2012 (2012) 03C009.
[2] H. Kumagai et al., Nucl. Instrum. Methods Phys. Res. B 317 (2013) 717.
[3] M. Kanazawa et al., Nucl. Phys. A 746 (2004) 393c.
[4] K. Wakayama et al., JPS Conf. Proc., to be published.

10

2.3

Measurements for nitric acid produced by proton beam irradiation in ahumidified air

Y. Nakai1, S. Tomita, R. Suganuma, S. Hattori2, K. Kobayashi2, Y. Shiina, S. Ishino2, N. Yamamoto,
K. Sasa
Atmospheric chemical processes induced by galactic and solar cosmic rays and their influences on theatmosphere environments have attracted attentions in these days. Gas-phase nucleation induced byionizing particles as cosmic rays has been discussed as one of important processes leading to cloudparticle formation [1, 2]. In humidified gas involving a trace SO2, generation of small droplets is enhanced
by sulfuric acid formed by ionizing radiation [3]. Moreover, it is known that massive injection of ionizing
particles into the atmosphere, such as solar proton events, causes an increase of the atmospheric nitric acidbeing a main reservoir of nitrogen oxides [4]. Thus, through laboratory studies of formation of nitric acidand sulfuric acid by ionizing particles [5], one can potentially obtain helpful information of elementary
chemical processes for understanding of atmospheric influences of cosmic rays. However, sufficient
information has not been given experimentally yet. We have investigated formation processes of sulfuric
acid and nitric acid induced by irradiation of protons. In 2017, we performed measurements of nitric acidproduced by irradiation of a proton beam in humidified air.
The sample air was generated by mixing pure dry air and wet air produced by bubbling a pure air in an
ultra-pure water. The humidity of the sample air was adjusted by controlling the mixing ratio between the
wet and dry air with mass flow controllers and was monitored with a dew-point meter. The sample air was
introduced into a borosilicate glass tube with a length of 25 cm, where its total flow rate was kept at 2.5
SLM (Standard Liters per Minute). The 6 MeV proton beam delivered from the 6MV Pelletron tandem
accelerator at UTTAC was introduced into the glass tube through a polyimide-film window. The beam
penetrated along the glass tube filled with the flowing sample air. The irradiated sample air wastransported into the filter-pack instrument. Three kinds of filters were stacked in it along a gas flow forcollection of gas-phase nitric acid and other species (Filter-pack method [5]). A polyamide membranefilter was used for collection of gas-phase nitric acid. The collected nitric acid on the filter was dissolvedin a 40 mL ultra-pure water. The amount of nitric anion, NO3-, in the solution was measured with ion
chromatography analysis. The amount of gas-phase nitric acid in the gas passing through the filter was
estimated from those of NO3- in the solution by assuming the collection efficiency of 100%.
In Fig. 1, preliminarily results are shown for the concentrations of gas-phase nitric acid produced by
the proton irradiation under the condition of 1 atm pressure, ~42 % relative humidity, and ~296 K
temperature. The concentration was calculated by dividing the amount of estimated gas-phase nitric acidby a total volume of the air passing through the filter. The production of nitric acid is found to be almost
proportional to the beam current. Items to be considered still remain, such as collection efficiency ofgas-phase nitric acid. Further analysis and consideration are proceeding.
1
2

RIKEN Nishina Center
School of Materials and Chemical Technology, Tokyo Institute of Technology

11Fig. 1. Concentrations of gas-phase nitric acid in the
proton-irradiated sample air versus beam currents (preliminary).

References[1] J. Curtius et al., Space Sci. Rev. 125 (2006) 159.
[2] F. Arnold, Space Sci. Rev. 137 (2008) 225.
[3] S. Tomita et al., Nucl. Instr. Meth. Phys. Res. B 365 (2015) 616.
[4] B. Funke et al., Atmos. Chem. Phys. 11 (2011) 9089.
[5] M. B. Enghoff et al., Atmos. Chem. Phys. 12 (2012) 5319.
[6] Network Center for EANET, Technical Manual for Air Concentration Monitoring in East Asia (2013).

12

3.
ACCELERATOR MASS SPECTROMETRY3.1

Operational status of the Tsukuba 6 MV multi-nuclide AMS system infiscal 2017

K. Sasa, T. Takahashi, T. Matsunaka1, S. Hosoya2, M. Honda, Y. Ota, K. Takano, Y. Ochiai, M. Matsumura,
K. Sueki
The AMS system on the 6 MV tandem accelerator was operated a total of 47 days in fiscal 2017. We
measured 613 samples in total dealing with rare radionuclides such as 36Cl, 41Ca, 90Sr and 129I, as issummarized in Table 1. Figure 1 shows a breakdown of measured nuclides. Figure 2 shows monthlymeasured nuclides from April 2017 to March 2018. 36Cl was measured most frequently in the fiscal year2017 in order to investigate the radiative contamination in rainwater and soil samples by the Fukushima
Daiichi Nuclear Power Plant accident and the trace of cosmic ray events in the ice core.

Table 1. Number of samples
measured in the fiscal year 2017.
NuclidesNumber

Cl

322

Ca

29

Sr

119

I

143

Total

613

36
41

90

129

I-129
23%

Sr-90
19%

Cl-36
53%

Ca-41
5%
Fig. 1. Breakdown of the nuclides measured by themulti-nuclide AMS system in the fiscal year 2017.

120

Number of pieces

100
80
Sr-90
I-129
Ca-41
Cl-36

60
40
20
0

Apr-17 May-17 Jun-17

Jul-17Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18

DateFig. 2. Breakdown of the nuclides measured monthly by the multi-nuclide AMS system from April 2017
to March 2018.
1
2

Kanazawa University
The National Institutes for Quantum and Radiological Science and Technology (QST)13

We have been developing ultrasensitive detection techniques for 41Ca−AMS with the multi-nuclide AMS
system. 41Ca (T1/2 = 1.04 × 105 yr) is produced by neutron capture of 40Ca or spallation reactions in the
primary targets. Accordingly, 41Ca is an ideal tracer for dating the exposure age of meteorites and terrestrial
surfaces. 41Ca is also used for biomedical applications. The ion source can extract CaF3− beams up to 500
nA from CaF2. We use the terminal voltage of 6.0 MV for 41Ca−AMS. Carbon stripper foils (4.8 μg/cm2)
are used for 41Ca−AMS to obtain highly charged ions. We tried to detect a charge state of 41Ca5+ with a totalenergy of 32.5 MeV in 2017. The beam transmission of 41Ca5+ was about 7 %. A multi-plate gas-ionization
detector was employed to separate 41Ca spectrum from isobaric interferences of 41K. Figure 3 shows twodimensional spectra for a blank sample and a standard sample of 41Ca/Ca = 1.155 × 10−10. Figure 4 shows
the calibration curve for 41Ca measurements with 6 standard samples [3]. We obtained a background levelof 41Ca/Ca down to about 3 × 10−15 and a measurement precision of 3% for 9.76 × 10−12 isotopic ratio using
the multi-nuclide AMS system.

Fig. 3. Two-dimensional spectra of 41Ca−AMS measured with the five-anode ΔE−E gas
ionization detector and measuring time of 5 min. (a) Blank sample. (b) Standard sample of41
Ca/Ca = 1.155 × 10−10.

Fig. 4. Calibration curve for 41Ca measurements of standard samples [3].
References[1] K. Sasa et al., Nucl. Instr. Meth. Phys. Res. B 361 (2015) 124.
[2] S. Hosoya et al., Nucl. Instr. Meth. Phys. Res. B 406 (2017) 268.
[3] K. Nishiizumi et al., Nucl. Instr. Meth. Phys. Res. B 172 (2000) 399.

14

3.2

Temporal variation of 36Cl in monthly precipitation at Tsukuba before
and after the FDNPP accident

Y. Ochiai, K. Sasa, Y. Tosaki1, T. Takahashi, M. Matsumura, S. Hosoya, K. Takano, Y. Ota, K. Sueki
On March 11, 2011, the Great East Japan Earthquake and the subsequent tsunami damaged the
Fukushima Daiichi Nuclear Power Plant (FDNPP). A large number of radionuclides including 131I and134

Cs were released to the environment. 36Cl was also one of the nuclides released from the FDNPP

accident, which was expected to be produced by a nuclear reaction of neutron and 35Cl in the coolant, i.e.,35

Cl (n, γ ) 36Cl. However, little is known about the total released amount or behavior of 36Cl in theenvironment because of the difficulty in its detection. This report focuses on the temporal variation of 36Cl
in precipitation derived from the FDNPP accident by the measurement of 36Cl / Cl.
We collected rainwater samples monthly from January 2010 to December 2012 at the University ofTsukuba. Cl− in rainwater was extracted using the ion exchange method and precipitated as AgCl with 0.3
M AgNO3. The precipitation was washed with ultrapure water and ethanol, and was loaded with a sample
holder. Measurements of 36Cl were conducted with AMS at UTTAC [1]. The background level of thesystem for 36Cl-AMS is 36Cl / Cl = 3 × 10−15, which is the lowest one obtained in Japan. Some parametersfor 36Cl-AMS were as follows: the terminal voltage of 6.0 MV, the detected ion of 36Cl8+ (56.0 MeV), andthe measurement time of 300 seconds × 8 times per one sample.

Fig. 1. The temporal variation of 36Cl in monthly precipitation. The hatchedarea shows the monthly average of 36Cl from April 2004 to December 2009.

Figure 1 shows the variation of 36Cl in the monthly precipitation at Tsukuba. The amount of 36Cl in
precipitation in March 2011 was (1.38 ± 0.02) × 109 atoms m−2 month−1 which was 17 times higher than
the average in March from 2005 to 2009, (8.0 ± 5.1) × 107 atoms m−2 month−1 [2]. The result waspresumed to be caused by the FDNPP accident because there is no similar data before March 2011 and1Geological Survey of Japan, AIST

15

recent studies reported the release of 36Cl by the FDNPP accident [3]. The amount of 36Cl in precipitationin October 2011 was (1.49 ± 0.04) × 109 atoms m-2 month-1 which was higher than the amount of 36Cl in
precipitation in March 2011. However, we have not clarified the cause and further investigation isnecessary.
Figure 2 shows comparison of the variation of 36Cl in monthly precipitation with that of 129I [4] from
September 2010 to February 2012. It is found that 36Cl correlates strongly with 129I from April to
September 2011 (correlation number r = 0.7). Therefore, the behavior of 36Cl is considered to be similar tothat of 129I in the environment. In March 2011, the ratio of deposition of the two nuclides is 129I / 36Cl = 3.1
× 103. In addition, the total amount of 129I released from the FDNPP accident is estimated to be 8.1 GBq,
according to recent investigations [5]. Assuming that 36Cl emitted from the FDNPP accident wastransported and deposited in the same way as 129I, the total amount of released 36Cl is estimated to be 0.14
GBq. It is presumed that 36Cl has relatively a small impact on the environment because its amount ofemission is 8–9 orders of magnitude less than that of 131I (151 PBq) [6] or 137Cs (14.5 PBq) [6] which
possibly cause serious effects on human bodies.

Fig. 2. Comparison of 36Cl and 129I in monthly precipitation.

References[1] K. Sasa et al., Nucl. Instrum. Meth. Phys. Res. B 361 (2015) 124.
[2] Y. Tosaki et al., J. Environ. Radioactiv. 106 (2012) 73.
[3] Y. Miyake et al., Nucl. Instrum. Meth. Phys. Res. B 361 (2015) 627.
[4] M. Matsumura et al., Geochem. J. 52(2) (2018) 155.
[5] X. Hou et al., Environ. Sci. Technol. 47(7) (2013) 3091.
[6] G. Katata et al., Atom. Chem. Phys. 15 (2015) 1029.

16

3.3

36

Cl record in the Antarctic ice core around the cosmic-ray event of 5480
BC studied with 36Cl AMS

K. Takano, K. Sasa, T. Takahashi, Y. Tosaki1, S. Hosoya, Y. Ota, Y. Ochiai, K. Sueki, K. Horiuchi2
Cosmic rays are high energy particles that come to the earth from the outside solar system. Theyinteract with atoms and molecules in the atmosphere, which is responsible for the production ofcosmogenic nuclides such as 14C, 10Be, 26Al and 36Cl. Therefore, the concentration of cosmogenic nuclides
reflects the intensity of cosmic rays. Miyake et al. [1] measured 14C contents in pine tree rings with 1- to
2-year time resolution for the period from 5490 BC to 5411 BC, and found a large 14C increase around5480 BC. To further investigate the cause of the increase, we tried to detect such a cosmic ray event bymeasuring cosmogenic 36Cl in ice core samples from the Dome Fuji, Antarctica. 36Cl is produced in theatmosphere by the spallation reaction of incoming cosmic rays with 40Ar, and it falls down and deposits in
the ice core.
For detection of cosmic-ray events in the Antarctic ice core, high time-resolution records are required
together with measurements of the 36Cl/Cl ratio on the order of 10−14. Therefore, we needed to improveisobar (36S) separation techniques for high sensitivity 36Cl measurements with the 6 MV AMS system at
UTTAC [2]. We tried to use AgBr as the backing material in sample holders in order to reduce
interferences of 36S [3]. The AgBr materials were prepared under different chemical processing conditions
in order to compare the effect of 36S elimination. We added either concentrated HNO3 or NH4OH tosaturated KBr solution. In this report, we refer to the former as the acid condition and the latter as thealkaline condition. Then, AgBr was precipitated with saturated AgNO3. Finally AgBr were centrifuged andwashed with ultrapure water and ethanol. Table 1 shows the result of the measurements for the threecases .We obtained the lowest isobar (36S) interference with AgBr precipitated under the acid condition.
Table 1. Comparison of isobar contribution with AgBr materials prepared under
different conditions. The counts of 36S are normalized to the 35Cl current value.

36

S / 35Cl

AgBr-reagent

AgBr-alkaline

AgBr-acid2.31 ± 0.47

2.16 ± 0.26

0.49 ± 0.22

Owing to the improved 36Cl-AMS, 36Cl / Cl ratios on the order of 10−14 can be measured with highprecision. We thereby measured 36Cl concentrations in the Dome Fuji ice core around the 5480 BC event.
The depth interval of each sample is 50 cm which corresponds to about 20 year interval. We added ~0.75
mg of Cl carrier to each sample (approximately 90-180 g in weight), which resulted in measured 36Cl / Clratios of 2.04 × 10−14−13.5 × 10−14 around the 5480 BC event. Figure 1 shows the variation of the 36Cl
1
2

Geological Survey of Japan, AIST
Hirosaki University

17

concentrations which ranges from 0.3 × 104 to 1.1 × 104 atoms g−1. There is a small increase in theconcentration of 36Cl around 5480 BC. Further studies should include measurements of cosmogenic
nuclides of 10Be and 36Cl with higher time resolution in order to reveal the origin of cosmic rays aroundthe 5480 BC event.

Fig. 1. Measured results of 36Cl concentration.

References[1] F. Miyake et al., PNAS 114 (2017) 881.
[2] K. Sasa et al., Nucl. Instr. Meth. Phys. Res. B 361 (2015) 124.
[3] S. Hosoya et al., UTTAC Annual Report 2016, UTTAC-86 (2017) 18.

18

3.4

Depth profile of 36Cl in the soil at Fukushima after the Fukushima Daiichi Nuclear Power Plant accident

Y. Ota, K. Sueki, K. Sasa, T. Takahashi, T. Matsunaka1, M. Matsumura, Y. Satou2, S. Hosoya, K. Takano,Y. Ochiai
In the environment, 36Cl (T1/2 = 3.01 × 105 yr), the major radioisotope of chlorine, is mainly produced by
the reaction 40Ar (p, 2p3n) 36Cl as a cosmogenic nuclide. In addition, nuclear weapon tests at oceanic sites
between 1952 and 1958 led to the release of large amounts of artificial 36Cl into the atmosphere. Before the
Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, 36Cl remained as a tracer in the soil. We hadmeasured 36Cl/Cl continuously by the former AMS system at UTTAC until 2011 [1−3]. The ratio of 36Cl/Cl
in the surface soil varied in the range of (0.09−4.10) × 10−13 at Futaba- and Okuma-machi, Fukushima in2008 and 2009 [3]. After the FDNPP accident, the 36Cl/Cl ratios were (0.11−2.63) × 10−11 for the surface
soil samples collected at 10 sites around the FDNPP on April 20, 2011 [4]. The pronounced increase of 36Cl
is probably due to the FDNPP accident. For further investigations, we measured 36Cl/Cl by the new AMS
system at UTTAC [5]. The ratios of 36Cl/Cl were obtained in the range of (0.01−1.00) × 10−11 from thesurface soil samples collected at 31 sites around the FDNPP from June 2013 to November 2016. The
measurements of 10 sites were reported in 2016 [6]. Meanwhile, it was believed that chlorine is non-reactive
and moves simply with water in the soil. Measurements of the surface soil might not be enough for revealing
the deposition density of 36Cl released from the FDNPP accident. Thus, we obtained the depth profile of 36Cl
in the soil at Fukushima to investigate the movement of 36Cl.
We collected 30-cm-long soil coresat Namie-machi, Fukushima (37° 33′
39″E, 140° 49′ 41″N) on June 2013
and September 2017. Soil cores weresliced into the thicknesses of 0.7 to 4
cm. The subdivided soil samples werevacuum-freeze-dried

andsievedthrough 2 mm mesh. Fractions of lessthan 2mm were pulverized by an agateball mill (200 rpm, 15 min × 3 times).
Then, we obtained the concentrated
solution of 36Cl− following the sample
preparation scheme (Fig. 1) designedwith reference to Tamari (2009),
Amano (2011) andBastviken et al.

(2007) [2, 3, 7]. Then, we conducted1
2

Fig. 1. Sample preparation scheme to extract 36Cl−.

Kanazawa University
Japan Atomic Energy Agency (JAEA)

19

the operation to remove 36S that interferes 36Cl-AMS, and prepared as AgCl. The detailed procedure is
described elsewhere [6]. The 36Cl/Cl ratio was measured by the AMS system. The terminal voltage foracceleration was 6.0 MV and the detected ion was 36Cl8+. The measured 36Cl/Cl ratios were normalized byusing the 36Cl standard (36Cl/Cl = 5.00 × 10−13) developed by Sharma et al. [8].
Figure 2 shows the depth profiles of 36Cl/Cl, 36Cl− and Cl− concentrations in 2013 and 2017. The 36Cl/Cl
ratios ranges from 10−12 to 10−11. In comparison with the 36Cl/Cl ratio before the FDNPP accident, the 36Cl/Cl
ratios are high not only near the surface, but also even at a depth of 5 cm or more. This fact indicates that36

Cl released from the FDNPP accident deposited into the soil and moved downward until 2013. Therefore,

it is very difficult to determine the deposition density of 36Cl− using the surface soil. Meanwhile, recent study
has shown that Cl− is converted into chlorinated organic compounds (Clorg) [5]. It has been implied that morethan 40% of the total Cl in the surface soil are Clorg in the boreal and temperate zones [9]. For this reason,
the depth profile of 36Clorg is required. If 36Cl released from the FDNPP accident is converted into 36Clorg andretained in surface soil, we may estimate the deposition density of total 36Cl (= 36Cl− + 36Clorg) instead of
36

Cl−.

Fig. 2. Depth profiles of 36Cl/Cl, 36Cl− concentration and Cl− concentration in soil at Namiemachi, Fukushima (37° 33′ 39″E, 140° 49′ 41″N) on June 2013 and September 2017.

References[1] R. Seki et al., Nucl. Instr. Meth. Phys. Res. B 259 (2007) 486.
[2] M. Tamari, Master’s thesis, University of Tsukuba 2009 (in Japanese).
[3] T. Amano, Master’s thesis, University of Tsukuba 2011 (in Japanese).
[4] Y. Miyake et al., Nucl. Instr. Meth. Phys. Res. B 361 (2015) 627.
[5] K. Sasa et al., Nucl. Instr. Meth. Phys. Res. B 361 (2015) 124.
[6] Y. Ohta et al., UTTAC Annual Report 2016 (2017) 20.
[7] D. Bastviken et al., Geochimica et Cosmochimica Acta 71 (2007) 3182.
[8] P. Sharma et al., Nucl. Instr. Meth. Phys. Res. B 52 (1990) 410.
[9] D. Bastviken et al., SKB TR-13-26 (2013).

20

3.5

Anthropogenic iodine-129 in the Japan Sea Bottom Water in 2017

T. Matsunaka1, S. Nagao1, M. Inoue1, S. Ochiai1, T. Morita2, S. Miki2, T. Aramaki3, I. Kudo4, N. Honda2,
T. Takikawa5, K. Sueki, M. Honda, K. Sasa
The Japan Sea is a semi-enclosed deep marginal sea in the northwestern North Pacific with the maximum
depth of ~3700 m. The sea is one of the reservoirs and monitors for emitted anthropogenic pollutants suchas radionuclides from nuclear activities and hazardous organics from human activities. The Japan Sea has
surface subtropical and subarctic circulations and has deep convection system of the Japan Sea Bottom
Water (JSBW). The long-term observation revealed that warming and oxygen decrease of the JSBW respondsensitively to air temperature raise in winter [1]. The relatively wide range of turnover time for the JSBW
were estimated to be 75–380 years detecting bomb-derived 14C [2–3]. Further investigation of water
dynamic in the Japan Sea using radioactive tracer is of essential importance not only for elucidating theinteraction between climate change and the convection system, but also for understanding the behavior of
the marine pollutants.
Anthropogenic 129I (T1/2 = 15.7 million years) produced from the thermal neutron fission of 235U and239

Pu is released dominantly by nuclear fuel reprocessing plants in the northwestern Europe. Less

radiologically harmful 129I provides information about the deep ventilation of sea water in the North Atlantic.
The main pathway of such pollutants to reach the Japan Sea is considered to be atmospheric transportationfrom the northwestern Europe, especially for 129I [4]. The main objective of this study is to illuminate theavailability of 129I as a tracer of surface circulations and vertical convections in the Japan Sea and Okhotsk
Sea. Therefore, we investigated the horizontal and vertical distributions of 129I in the large area of these seasin 2017.
The radioactivity of dissolved 129I in surface water varied from 17.3 ± 0.7 to 23.1 ± 1.0 nBq L–1 at thearea of 38–46⁰N and 135–141⁰E in the Japan Sea, and was negatively correlated with salinity (R2 = 0.82),
as shown in Fig. 1. This salinity-dependent distribution indicates that the dissolved 129I concentration in thearea is controlled by mixing of water mass from the Liman Current with low salinity to the Tsushima Current
with high salinity. Meanwhile, the mean radioactivity of dissolved 129I in the JSBW observed at the layer of
2480–3500 m of the Japan Basin in 2017 was 4.1 ± 0.5 nBq L–1, which increased by 1.1 nBq L–1 from thatin 2007 [5] (Fig. 2). The turnover time for the JSBW 205 ± 25 years, estimated using 129I, is consistent withthe literatures [2, 3]. These results demonstrate that 129I is a useful tracer for study of the surface subarctic
front and deep JSBW in the Japan Sea.

1

Kanazawa University
Japan Fisheries Research and Education Agency
3 National Institute for Environmental Studies
4 Hokkaido University
5 Nagasaki University
221

Fig. 1. Correlations between 129I radioactivity in sea water from the Japan Sea and latitude (A) and salinity(B). The linear regression lines and the coefficient of determination R2 are shown in the diagrams.

Fig. 2. Vertical distributions of 129I in the Japan Basin observed in 2007 [5] and 2017 (this study). The
boundaries of surface water, upper proper water, deep water, and bottom water are shown on the right.
(B) shows the laterally enlarged diagram of (A).

References[1] T. Gamo, Trends Anal. Chem. 30 (2011)1308.
[2] T. Gamo, Y. Horibe, J. Oceanogr. Soc. Japan 39 (1983) 220.
[3] Y. Kumamoto et al., J. Oceanogr. Soc. Japan 64 (2008) 429.
[4] T. Suzuki et al., Nucl. Instr. Meth. Phys. Res. B 294 (2013) 563.
[5] T. Suzuki et al., Nucl. Instr. Meth. Phys. Res. B 268 (2010) 1229.

22

3.6

Development of the prompt and sensitive determination method forstrontium-90 with accelerator mass spectrometry

S. Hosoya1, K. Sasa, M. Honda, T. Takahashi, Y. Satou2, K. Takano, Y. Ochiai, K. Sueki
Strontium-90 (90Sr; T1/2 = 28.79 yr) is a radioactive nuclide (β- decay) and the fission product of uranium
and plutonium. In fact, 90Sr was discharged into environmental by the Fukushima Daiichi Nuclear Power
Plant accident. Strontium is the same alkaline earth metal as calcium and its chemical properties are similar.
When 90Sr is taken into the body, it accumulates in the bone and causes internal exposure. The 90Sr
measurement is important for understanding the behavior of radioactive nuclides in environment and in vivo.
A conventional analysis method of 90Sr is the β decay counting. However, β decay counting requires the
milking process of 90Y. It is easier to measure the β ray from 90Y (2.28 MeV) than from 90Sr (0.54 MeV). It
takes two or three weeks to wait for the 90Y growth until the radioactive equilibrium is reached. Recently,
the ICP-QMS technique was developed for a rapid analysis of 90Sr [1]. However, its detection limit is rather
insufficient. Meanwhile, AMS has a great potential to enable quick and high-sensitivity measurement of 90Sr.
Table 1. Comparison of 90Sr analysis methods.
Detection limit
Analysis time

β decay counting

ICP-QMSAMS~ 1 mBq
60 min.+ Milking 2−3 weeks~ 20 mBq~ 15 min.

~ 0.1 mBq (90Sr/Sr ~ 10-14)~ 30 min.

The 90Sr analysis methods are compared in Table 1.
The ion source for AMS is of cesium sputtering type. Because strontium is alkaline earth metal element,
as mentioned above, the electron affinity is low so that the negative ion beam of strontium cannot be obtained
from the sputtering ion source. Hence we tried to extract
molecular ion beam of negatively charged SrF2. The nonconductor SrF2 was mixed with some conductive powder
to suppress electrical charging. Test results of beam
extraction is listed in Table. 2.

88

SrF3- could be

successfully extracted up to ~ 400 nA from the mixed

Table 2. Extracted 88SrF3 - currents fromvarious mixtures of SrF2.
Mixed powder
88
SrF3- current (nA)
(SrF2: others)
PbF2 (1:4)~ 400
Au (1:4)~ 300
Au (1:1)~ 150
Ta (1:4)~ 100

powder of SrF2 and PbF2.
The standard sample of high reliability is important for AMS to determine the quantity of an unknown
sample. We used the standard sample prepared from the Proficiency Test sample (PT sample). The PT
samples are distributed from IAEA and used as mutual evaluation sample at AMS facilities all over theworld. These samples are suitable for AMS because the reliable values are given by IAEA. The standard
sample was prepared by diluting the PT sample to an arbitrary ratio and making it according to the process
shown in Fig. 1. We prepared three standard samples of 90Sr/Sr = 3.38 × 10−9, 4.14 × 10−10, and 1.75 × 10−10.
Table 3 shows the system parameters of 90Sr AMS at UTTAC. The detector used is of 5-anode gas
1
2

Present address: The National Institutes for Quantum and Radiological Science and Technology (QST)
Japan Atomic Energy Agency (JAEA)

23

Table 3. System parameters of UTTAC
90
Sr AMS.
Sample material
SrF2
88
SrF3- (~ 400 nA)
Extracted beam
Terminal voltage 6 MV
StripperCarbon foil
(3.8 μg/cm2)
90 8+
Sr
Detected ion
Transmission~8%
Beam energy
51.8 MeV
Detector gas
Isobutane
Detector window Si3N4 (75 nm)

Fig. 1. 90Sr-AMS standard sample preparation scheme.

ionization type. Details of the detector setup and the isobar (90Zr) separation technique are described in Ref.
[2]. 90Sr8+ could be detected at 30 Torr of the detector gas of isobutane, as is seen in Fig. 2.

Fig. 2. AMS results for the standard sample(90Sr/Sr = 3.38 × 10−9) and the blank sample(commercial reagent) spectra.

Fig. 3. Measured ratios of 90Sr/Sr for the standard
samples vs. the known ratios for the PT sample.

Results of the measurements for the 3 standard samples are plotted against the known ratios for the PT
sample in Fig. 3, which assures consistency of the whole experimental procedure. The background level
was measured by using the blank sample (commercial reagent) and its level of90

Sr/ Sr ~ 6 × 10−13(equivalent to 90Sr ~ 3 mBq) has been obtained. Until now, Lawrence Livermore National Laboratory has
been the only facility that allows AMS measurements (using the 10 MV tandem accelerator) of 90Sr with thesame background as the level above [3]. In this research, the world’s highest-level performance has beenachieved at UTTAC. The present work has demonstrated the prompt and sensitive analysis of 90Sr using our
AMS, compared with the conventional 90Sr analysis method.
References[1] Y. Takagai et al., Analytical Method 6 (2014) 355.
[2] S. Hosoya et al., UTTAC Annual Report, UTTAC-85 (2016) 17.
[3] S. J. Tumey et al., Journal of Radioanalytical and Nuclear Chemistry 282 (2009) 821.

24

3.7

Trial of determination of 41Ca in stony meteorites by accelerator mass
spectrometry

Y. Oura1, T. Hara1, S. Hosoya, K. Takano, Y. Ochiai, T. Takahashi, K. Sueki, K. Sasa
Chlorine-36 and 41Ca are cosmogenic radionuclides found in meteorites and produced by several
nuclear reactions such as proton and secondary neutron induced spallation reactions and neutron capture
reaction. We determined 36Cl concentrations in chondrites and iron meteorites by accelerator mass
spectrometry (AMS) system at UTTAC to study irradiation histories of meteorites. In 2016 we tried todetermine 41Ca concentration in iron meteorite by using a new AMS system at UTTAC [1]. In 2017 we
tried to determine 41Ca concentration in stony meteorites by AMS.
In mass spectrometry including AMS, isobars sometimes interfere in the determination of nuclide ofinterest. Stony meteorites contain more K (41K) than iron meteorites (containing almost no K). Using aradiotracer, a chemical separation procedure for Ca in stony meteorites was evaluated especially forremoval of K. The evaluated procedure was applied to two stony meteorites, Gao and Dajala meteorites,
and their 36Cl concentrations and elemental concentrations were determined by the former AMS system at
UTTAC [2] and a neutron activation analysis, respectively.
About 0.1 g of powdered samples was dissolved in dil. HNO3 after an alkali fusion with Ca carrier (5 −10 mgCa) and Cl carrier (2 − 4 mgCl). AgNO3 was added to precipitate AgCl. Ammonia water was added
to the supernatant solution to adjust pH into 5.4 − 5.8, then Fe(OH)3 was precipitated. Also, CaC2O4 was
precipitated by adding (NH4)2C2O4 in the supernatant solution followed by dissolution of CaC2O4 in 6
mol/L HCl. Remained trace Fe in this solution was removed by anion exchange method, and then CaF2
was finally obtained by adding HF to the eluate containing Ca. Although CaF2 was heated at 500°C for
determination of 41Ca in iron meteorites in 2016, CaF2 was heated at 110°C overnight in this study. Final
Ca fractions were divided into halves, and both halves were subjected to AMS measurement independently.
Additionally reagent blank and procedure blank were also determined.
In AMS measurement of 41Ca, the terminal voltage of the tandem accelerator was set to 6 MV and41

Ca5+ and 40Ca5+ were measured for about 3000 sec (10 times of 300 sec ) or 5000 sec by gas ionization

detector and Faraday cup, respectively (in 2016 Ca7+ was measured similarly). The calibration curve
obtained is shown in Fig. 1 and good correlation between the 41Ca / 40Ca count ratio and the certified 41Ca /40

Ca atomic ratio is observed. The results for stony meteorites are tabulated in Table 1. In stony meteorites

41

K / 40Ca content atomic ratio is about 0.006 whereas the detected 41K / 40Ca count ratios are about 1 ×

10-8. Although the detected counts of 41K were greater than of 41Ca, K was removed enough to detect 41Ca.
Determined 41Ca concentrations in two portions (A and B) for the two meteorites demonstrate good
reproducibility of the present measurements of 41Ca / 40Ca.
For Dajala meteorite, in which 36Cl concentration is 16 dpm/kg, about 100 counts of 41Ca was
obtained, corresponding to the 41Ca concentration of 14 dpm/kg. Also, the concentration of 41Ca wasestimated to be 14 dpm/kg, which resulted from combination of the determined 36Cl concentration and the1

Tokyo Metropolitan University

25

model calculation by Ammon et al. [3]. The 41Ca concentrations in Dajala determined agree with theestimated concentration, mentioned earlier, indicating that the determined values of 41Ca are believed to beaccurate. On the contrary, for Gao meteorite, the two different concentrations of 36Cl determined are 9.95
[2] and 5.93 dpm/kg are about 3 − 5 times larger than the estimated concentration. It is probable that the
specimen of Gao meteorite for 41Ca determination is different from those for the former 36Cl determination.
Determination of 36Cl by using the Cl fraction of Gao meteorite will help to solve the discrepancy.

Fig. 1. Calibration curve for 41Ca obtained by measurement of 41Ca standard samples.
Sensitivity of 41Ca when using Ca5+ is almost the same as using Ca7+ at the run in 2016.

Gao
DajalaA
B
A
B

Measurement
time [s]
3000
3000
3000
5000

Table 1. Results for iron meteorites.
41
Count of Atomic 41Ca / 40Ca
Ca
41
-12
[× 10 ]
Ca
[dpm/kg]
380
2.1
25 ± 1295
2.0
24 ± 167
0.73
14 ± 2128
0.73
14 ± 1

Estimated 41Ca Count of
41[dpm/kg]
K
5, 8
2010
1662
14
542
1781

In reagent blank and procedure blank, 2.3 × 10-5 dpm and 3.0 × 10-5 dpm of 41Ca were detected,
respectively, using about 5 mg of Ca carrier. These are 30 − 100 times smaller than the detected 41Ca infour meteorites samples. Assuming that a minimum limit of detection is two times that of 41Ca in blanksample, down to 0.3 dpm / kg is found to be detectable if a sample of 0.1 g is used and Ca carrier of 4 mg
is added.
References[1] Y. Oura et al., UTTAC Annual Report 2016, UTTAC-86 (2017) 30.
[2] Y. Hamanaka et al., UTTAC Annual Report 2008, UTTAC-78 (2009) 27.
[3] K. Ammon et al., Meteoritics and Planetary Science 44 (2009) 485.

26

4.
BEAM AND ISOTOPE APPLICATIONS

4.1

Carrier trapping by vacancy-type defects in Mg-implanted GaN studied
using monoenergetic positron beams

A. Uedono, S. Takashima1, M. Edo1, K. Ueno1, H. Matsuyama1, W. Egger2, T. Koschine2,
C. Hugenschmidt3, M. Dickmann3, K. Kojima4, S. F. Chichibu4, S. Ishibashi5
Vacancy-type defects in Mg-implanted GaN are probed using monoenergetic positron beams. Mg+
ions are implanted to provide a 500-nm-deep box profile with Mg concentrations, [Mg], of 1×1017–1×1019
cm−3 at room temperature [1]. In the as-implanted samples, the major defect species is a complex of a Ga
vacancy (VGa) and a nitrogen vacancy (VN). After annealing above 1000℃, the major defect species ischanged to vacancy clusters due to vacancy agglomeration. This agglomeration is suppressed, and theagglomeration onset temperature is decreased with a decreasing [Mg]. For samples with [Mg] ≥ 1×1018
cm−3, the trapping rate of positrons by vacancy-type defects decreases after annealing above 1100–1200℃.
This decrease is attributed to the change in the defect charge states from neutral to positive due to adownward shift of the Fermi level. The carrier trapping/detrapping properties of the vacancy-type defects
and their time dependences are also revealed. Results are shown in Figs. 1-11.

Fig. 3. Annealing behaviors of S
for Mg-implanted GaN.

Fig. 1. S parameters as a functionof the incident positron energy E.

Fig. 2. Depth distribution of S
obtained from the analysis.

Fig. 4. Annealing behaviors of themean lifetime for Mg-implanted GaN.
1

Fuji Electric Co., Ltd.
Universität der Bundeswehr München
3
Technische Universität München
4
Tohoku University
5
National Institute of Advanced Industrial Science and Technology (AIST)
2

27

Fig. 5. S–W relationships for Mgimplanted GaN. with [Mg]=1×1017
cm−3.

Fig. 6. S–W relationships for Mgimplanted GaN. with [Mg]=1×1018
cm−3.

Fig. 8. Lifetimes (τ1, τ2, and τ3) and the corresponding
intensities (I2 and I3) for Mg-implanted GaN with
[Mg]=1×1017 cm−3 after annealing at 1300℃ and with
[Mg]=1×1019 cm−3 after annealing at 1000℃.

Fig. 7. S–W relationships for Mgimplanted GaN. with [Mg]=1×1019
cm−3.

Fig. 9. a) PL spectra measured at 10K, andb) S values for Mg implanted GaN.

Fig. 10. Schematic band diagram and possible
transition levels of the vacancy-type defects, where
VBM and CBM are the valence band maximum andconduction band minimum, respectively.

Fig. 11. Time dependence of S measured at E.=8 keV
for Mg-implanted GaN with [Mg]=1×1017 cm−3.

Reference[1] A. Uedono et al., Phys. Status Solidi B 255 (2018) 1700521.

28

4.2

Two-dimensional mapping of hydrogen and other elements withmicrobeam-based transmission ERDA and PIXE

A. Yamazaki, H. Naramoto, K. Sasa, S. Ishii, S. Tomita, M. Sataka, H. Kudo, A. Uedono
Light trace elements in structural materials often affect their characteristics. PIXE measurements
combined with microbeam scanning are frequently performed for mapping of trace elements in materials.
Recently, development of thin window semiconductor detector has enabled detection of soft X-rays thatare emitted from light elements such as boron, carbon and nitrogen, and microbeam PIXE becomes more
and more useful for imaging light trace elements.
Hydrogen also plays an important role for some mechanical properties of materials. However, the
PIXE analysis is not applicable to hydrogen detection since hydrogen atom emits no characteristic Xrays. Alternatively, we can use the ERDA method as an ion beam analysis of hydrogen. Especially,
ERDA in the transmission geometry, i.e., transmission ERDA is suitable for the 2D mapping of hydrogenin thin samples. It is notable that in this energy range of He ions, the hydrogen recoil cross section isvery large (a factor of up to ∼400 greater than that of the Rutherford cross section) , while the influenceof bremsstrahlung is relatively low. In FY2017, we tried to obtain 2D maps of hydrogen and other elements simultaneously by parallel processing of signals from microbeam transmission ERDA and frommicrobeam PIXE.
Experimental setup of the simultaneous measurements for ERDA and PIXE is illustrated in Fig. 1. A
4 He beam of 8 MeV was provided by the 6MV tandem accelerator at UTTAC and its microbeam scanningwas performed with the OM-2000 microbeam focusing and scanning system installed at L3 course of thetamdem accelerator facility [1]. The model sample prepared consists of three layers: a copper fine grid of
4–7 µ m thickness (200 lines/inch, bar and hole widths of 12 and 113 µ m, respectively), a 3.5-µ m thick
Mylar sheet, and a 80-µ m thick aluminum film. The aluminum film was placed as a stopper of the incident
4 He beam, but was thin enough for transmission of recoil hydrogen atoms.

Fig. 1. Experimental setup of the simultaneous measurements for ERDA and PIXE.

The beam size on the sample was evaluated using the scanning transmission ion microscopy in offaxis geometry (off-axis STIM). A copper fine mesh was scanned by the 4 He ion microbeam. A Si-PIN
photodiode was used to detect the forwardly scattered 4 He. The smallest beam diameter estimated fromthe sharpness of the edge profiles of the STIM images is 2 µ m. This value provides the spatial resolution29

of elemental distributions in samples.
Figures 2(a) and 2(b) show the measured transmission ERDA and PIXE spectra, respectively. The
recoil hydrogens from the Mylar sheet are recognized in the ERDA spectrum, reflecting the energy dependence of recoil cross section under the present experimental conditions. In the PIXE spectrum, the two
peaks around 1500 channel indicate copper Kα (8.05 keV) and Kβ (8.91 keV) X-rays.
6

800

(a)

ERDA

10

600

Cu
10

recoilinghydrogenKαCountsCounts

4

400

(b)

PIXE

Kβ
2

10

200

0
0

0

500

1000

10

0

1000

2000

ChannelChannelFig. 2. (a) ERDA and (b) PIXE spectra obtained by irradiating the sample with an 8 MeV 4 He beam.

Figure 3 shows measured elemental maps of hydrogen and copper in the sample. The hydrogen images
obtained by transmission ERDA is shown as orange-colored squares in Fig. 3(a). In contrast, Fig. 3(b)shows the simultaneously measured image of the copper fine mesh (yellow-colored) on the surface of thesample. These two maps are surely the reverse images of each other because the 4 He projectile that passes
through the copper grid no longer has sufficient energy to contribute to the hydrogen mapping. A pairof these maps provides complementary information on multi-elemental distributions in the sample. The
present results indicate that the combined PIXE-ERDA method might become a powerful tool beyond theexisting analytical methods.

Fig. 3. 2D elemental mapping of (a) hydrogen by ERDA, and (b) Cu K X-rays by PIXE.

References[1] A. Yamazaki et al., Nucl. Instr. Meth. Phys. Res. B 404 (2017) 92.
[2] A. Yamazaki et al., Submitted to Nucl. Instr. Meth. Phys. Res. B.

30

4.3

Production of 16 channel preamplifier module and development of highsensitivity HERDA equipped with strip SSD

D. Sekiba, K. Tsujita, Y. Sugisawa, I. Harayama, M. Uenomachi1, K. Shimazoe1, H. Takahashi2, K. Ozeki3
HERDA (High-resolution Elastic Recoil Detection Analysis) is a useful method to determine thehydrogen depth profile with mono-layer depth resolution [1, 2]. In the last decade, we have made efforts toimprove the detection limit for hydrogen by, for example, introducing the double MCP system [3] and/or
the moving SSD (solid state detector) system. While the use of the moving SSD as a position sensitive
detector can suppress the two main noise sources, i.e., dark currents and stray particles, it is really time
consuming. In order to solve this difficulty, we adopted a 16 channel strip PIPS (Passivated Implanted Planar
Si detector, CAMBERRA, type: PF-16RT-58*58-300EB) of 58×58 mm2, so that the pitch of the 16 pad is~ 3.6 mm.
For operation of the 16 channel strip PIPS, we made a 16 channel preamplifier module, in which thedown-sized preamplifier tips (see Fig. 1(a)) reported previously [4, 5] were installed. The home-made 16
amplifier tips were put in the two NIM module cases. Figure 1(b) and 1(c) show the inside and the front
panels of the NIM modules, respectively.

Fig. 1. (a) Down-sized preamplifier on a hand of Mr. Tsujita (the maker of the preamplifiers). (b) Inside of the
NIM modules, in which the 16 preamplifiers are settled. (c) Front panels of the developed NIM modules. A setof three connectors for input, output, and test pulse are allotted to each channel.

The 16 signal lines are extracted to the outside of the chamber via an electric feedthrough with the shape of
the D-sub connector. The signal lines were connected to the NIM modules of preamplifier beside thechamber. The outputs were connected to a home-made dToT (dynamic Time over Threshold) [6] module
put in a NIM case, in which CR-RC circuits and dToT circuits are installed.

1

Department of Nuclear Engineering Management, School of Engineering, The University of Tokyo
Institute of Engineering Innovation, School of Engineering, The University of Tokyo
3
Department of Mechanical Engineering, Ibaraki University
231

The test of the new system, in which the new detector and electronics were involved, was performed in
the D-course of 1MV Tandetron in UTTAC. The sample was a-C:H (hydrogenated amorphous carbon) film(t ~ 170 nm) deposited on a Si wafer. The hydrogen concentration in the film was 2.1×1022 atoms/cm3
determined by RBS (Rutherford backscattering)/ERDA. 1 MeV 16O+ was used as an incident beam. The
recoil angle was 30º with respect to the beam incident direction.
Figure 2(a) shows the measured histogram as a function of time over threshold at each channel. We cansee a series of peaks in the region surrounded by the two red dotted lines. These peaks correspond to thehydrogen recoils, and their yields are reconstructed as the HERDA spectra in Fig. 2(b) with the blue circles.
The spectrum qualitatively reproduced that taken by a conventional MCA (multi-channel analyzer) system(red circles), though ~15% of the signals seems to be lost with the developed dToT systems. Most of the lostpart could be included in the long tails seen in the short time side of Fig. 2(a). We will try to fix this problem
in the future. The detection limit of hydrogen derived from the HERDA spectrum with dToT is 8.0×1019
atoms/cm3 for 149 sec of data acquisition time.

Fig. 2. (a) Two-dimensional histogram of yield as a function of time and channel of the detector. The two red
dotted lines are ROI (Region of interest) of the yield integration. (b) HERDA spectra taken with the combinationof the strip PIPS and a commercially available preamplifier, normal shaper and MCA system (red) and taken withthe developed dToT system (blue).

References[1] K. Kimura et al., Nucl. Instr. Meth. Phys. Res. B 140 (1998) 387.
[2] D. Sekiba et al., Nucl. Instr. Meth. Phys. Res. B 401 (2017) 29.
[3] D. Sekiba et al., Nucl. Instr. Meth. Phys. Res. B 430 (2018) 6.
[4] Y. Hosono et al., Nucul. Instr. Meth. A 361 (1995) 554.
[5] K. Tsujita et al., UTTAC annual report 2016 (2017) 36.
[6] Y. Tiang et al., IEEE Trans. Nucl. Sci. 62 (2015) 1798.

32

4.4

Location of hydrogen in Mg/H-coimplanted GaN by RBS/ERDA andchanneling NRA

J. Kikuda, I. Hrayama, T. Ozawa1, K. Fukutani1, D. Sekiba
Gallium nitride (GaN) is a wide-band-gap semiconductor, which is promising for the optoelectronicand high-power devices. In spite of much effort on the device construction, the formation of p-type GaN
with the Mg implantation has still problems to be overcome. Some experimental results implied thathydrogen beside Mg passivates most of the acceptors (Mg in this case) [1]. It is believed that thesubsequent treatments after the Mg implantation, such as the high temperature flashing at ~1000 ºC or theelectron bombardment, induce the desorption of hydrogen. The removal of hydrogen would lead to thesettling of Mg on the correct Ga site. This scenario has, however, not been experimentally established yet.
In order to examine this scenario, we employed RBS/ERDA (Rutherford backscattering spectrometry /Elastic recoil detection analysis) and channeling NRA (Nuclear reaction analysis). In the present report,
the insights obtained on the hydrogen desorption temperature and the location in the lattice are reported.
RBS/ERDA was carried out in the D-course of 1MV Tandetron at UTTAC. A beam of 2.5 MeV 4He2+
was shaped to 1 × 1 mm2 by the single slit system. The recoil and backscattering angles are 30º and 150º
with respect to the beam direction, respectively [2]. The beam incident angle on the sample was 75º fromthe surface normal. The channeling NRA experiment with 1H (15N, αγ) 12C was carried out at Micro
Analysis Laboratory, Tandem accelerator (MALT) in the University of Tokyo. A beam of ~6.4 MeV 15N+
was shaped to 2 × 2 mm2 by the double slit system and the beam energy was tuned to explore the depth of
50 nm. The characteristic 4.43 MeV γ-rays were collected by the two 4-inch BGO scintillators.
The three-step dopant implantation was carried out as follows, 30 keV 24Mg+ with 3.5 × 1013 at/cm2 ,60 keV 24Mg+ with 6.5 × 1013 at/cm2, and 7 keV H2+ with 7.0 × 1014 at/cm2. Five different samples wereprepared with varying the subsequent annealing temperature: #1 at 900 °C, #2 at 950 °C, #3 at 1000 °C,#4 at 1050 °C, and #5 at 1100 °C.
Figure1 shows the ERDA spectra taken for the samples #2~5. The surface peaks observed at 1200 keV,are due to the adsorbates containing hydrogen.

10

On the sample #2 (red), we can observe a broad
This energy corresponds to the depth of theimplanted hydrogens. This broad peak disappears
for the sample #3, and no longer appears for the8

Yield (count)peak over the energy region of 700 ~ 1000 keV.

642

samples with the higher-temperature annealing(#4, #5). It is found for the first time that the0
200 300 400 500 600 700 800 900 1000 1100 1200 1300

co-implanted hydrogen desorbs at a temperature

Energy (keV)

between 950 °C and 1000 °C. It is of further

1

#2
#3
#4
#5

Fig. 1. ERDA spectra taken on GaN of #2~5.

Institute of Industrial Science, University of Tokyo33

interest to perform similar measurements for the samples annealed with a finer step of temperature.
Figure 2 shows the two dimensional (2D)25angles with respect to the vertical axis θ (polar)
6.4 MeV 15N2+ beam was incident on sample #1.

1.0

φ (degree)and horizontal axis φ (tilt). In this measurement, aA

2.0

mapping of RBS yields taken with sweeping the

20
15

B

0.0

10
-1.0
5

The angles (θ, φ) = (3.6, 0.0) correspond to the

C

-2.0

[0001] axis of GaN.
-3.0
-2.0

We performed NRA measurements at three

-1.0

0.0

0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

θ (degree)

points in the 2D map A (θ, φ) = (5.4, 1.7), B (θ, φ)

Fig. 2. 2D map of RBS yield taken withsweeping θ and φ.

= (3.6, 0), and C (θ, φ) = (0.6, −2.6) as indicatedin Fig. 2. These points correspond to random,

10

4

conditions, though the point C is slightly

10

3

10

2

channeling,

displaced

from

and
the

planarcorrect

position

notintentionally. Figure 3 shows the NRA spectra
taken

with

the

beam

incidence

angle

Yield (count)channelingaxial

corresponding to the points A ~ C in Fig. 2. We

10
10(θ, φ) = (5.4, 1.7)
(3.6, 0.0)
(0.9, -2.8)
background1

0

can see broad peaks at ~4.4 MeV slightly
10

distinguishable from the background in each

-1

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

Energy (MeV)

spectrum, which can be attributed to 4.43 MeV

Fig. 3. NRA spectra taken at the threepoints A ~ C indicated in Fig. 2.

γ-ray of 1H (15N, αγ) 12C.
Figure 4 displays the integrated yields ofthe 4.43 MeV γ-ray signals taken at the points A ~C. While the statistical errors are still large, it
seems that the yields for the axial and planarAchanneling are larger than that for the randomBcase. This implies that the considerable amount ofChydrogen stays at the interstitial site involved in
the axial and other planar channels. In future, acomparative study with similar measurements

Fig. 4. The amount of hydrogen determinedfrom the results shown in Fig. 3.

taken for the annealed samples should provide
detailed information on the behavior of hydrogen.

References[1] S. Nakamura et al., Jpn. J. Appl. Phys. 31 (1992) 1258.
[2] D. Sekiba et al., J. Appl. Phys. 106 (2009) 114912.

34

4.5

Present status of TOF-E telescope ERDA system development

Y. Sugisawa, D. Sekiba, I. Harayama
Recently, there are high demands for analysis of light elements in thin films. For instance, since thecontinuous control of anion composition in metal oxides enables us to tailor their optical, electronic andstructural properties, it is necessary to determine the compositional ratio of the anions, in particular of O
and N [1]. TOF (Time of Flight) -E (Energy) telescope ERDA (Elastic Recoil Detection Analysis) is aneffective method of depth profiling of light elements with the elemental identification [2]. It usually has abetter depth resolution than that of ΔE-E telescope ERDA [3]. This property is expected to be applicable tothe analysis of thin multilayer films. We have developed TOF-E telescope ERDA system mainly with theaim of the determination of O/N ratio and also with a sufficient depth resolution suitable for analysis ofmultilayer films, in which each layer has a thickness of several tens of nanometers.
In this system, the velocity and energy of a recoiling particle are measured coincidently, which allows
identification of the particle mass. Figure 1 shows a schematic view of the TOF-E telescope ERDA systeminstalled at D-course of 1 MV Tandetron at UTTAC. We employed two time-detectors, T1 and T2, and one
SSD (solid state detector) of 300 mm2. T1 and T2 generate the start and stop triggers in the TOF
measurement, respectively, while SSD determines the kinematic energy of the particle. The time-detectors
consist of MCPs (Micro Channel Plate), carbon foils with a thickness of 7 µg/cm2 andelectrostatic-mirror-grids, as shown schematically in Fig. 2 [4]. When the recoiling particle passes throughthe carbon foil, secondary electrons are emitted from the carbon foil and are reflected by the mirror grid.
They are then detected by MCP. The carbon foils T1 and T2 are set on the φ9 and φ15 mm apertures,
respectively. T1 is placed at 263 mm apart from the sample and the distance between the twotime-detectors is 428 mm. SSD is placed at 771 mm apart from the sample. In this layout, the solid angleof acceptance of the present system is 0.37 msr, taking into account the effective area of SSD.
In the present study, the incident beam was 4 MeV 35Cl4+ and the typical beam size was shaped toabout 1×1 mm2 with a double slit system. The beam was incident at 75º from the surface normal of thesample and the recoiling particles were measured at −75º from the surface normal. Accordingly, the recoil
angle was 30º from the beam direction. The typical beam current was several nA. The data acquisition
time was ~ 1 hour for one sample.
Figure 3 shows a two-dimensional histogram of the developed TOF-E telescope ERDA measured for a
Kapton film which is composed of H, C, N and O. The assignment of these elements is given in Fig. 3.
Note that the Cl ridge in the histogram results from the Cl ions that are scattered at 30º in the Kapton film.
The estimated time resolution of the present system is 1.5 ns and the corresponding mass resolution is 1.0
u (u: unified atomic mass unit) around the mass of O. Since the difference of mass for N and O is about 2u, these two elements are distinguishable with this setup. Figure 4 shows the line profile at 2.6 MeV,
obtained for a 48 keV energy width which is indicated with two vertical lines in Fig. 3. Certainly, we canrecognize C, N, and O peaks in Fig. 4.
In the present, there are two main problems in our TOF-E telescope ERDA system. One is the35difficulty in separating individual distributions of C, N, and O from the histogram, although peaks of eachelement are recognizable. To do this, it necessary to improve the time resolution which is determineddominantly by the signal processing system. The other is the total detection efficiency of the time-detectors, which is lower than that of SSD. The total detection efficiency of the current system estimatedfor 5 × 104 s was less than 2.6% so that most of the secondary electrons emitted from the carbon foil werelost before arriving at MCP. In future works, we are going to optimize the signal processing system anddevelop new time detectors to improve the time resolution and the detection efficiency.

grid (0 V)

771
264

428

aperture

SSD

30°

9

mirror grid (-3 kV)

Ｍ ＣＰ

carbon foil

beam

T1

sample
SSD for RBS

T2

aperture
MCP

Fig. 2. Arrangement of MCP, a carbon foil,
and an electrostatic mirror grid in the time
detector used in the present system.

Fig. 1. Schematic view of the developed TOF-E telescope
ERDA system.

Cl

C

O
N

Fig. 3. Two-dimensional histogram for a Kapton film
measured using the developed TOF-E telescope ERDA
system. Note that Cl ridge is due to scattered Cl ions.

Fig. 4. Line profile of the two-dimensional
histogram shown in Fig. 3 around 2.6 MeV
with the width of 48 keV.

References[1] A. Kobayashi et al., Phys. Status Solidi RRL 8 (2014) 362.
[2] J. Julin et al., Nucl. Instr. Meth. Phys. Res. B 406 (2017) 61.
[3] I. Harayama et al., Nucl. Instr. Meth. Phys. Res. B 384 (2016) 61.
[4] F. Busch et al., Nucl. Instr. Meth. 171 (1980) 71.

36

4.6

Experimental verification of a gain reduction model for the space charge
effect in a wire chamber

K. Fujii1, I. Harayama, Y. Kato1, N. Nagakura1, D. Sekiba, Y. Watahiki, S. Yamashita2
In our neutron lifetime precise measurement in J-PARC, we monitor and collect the tracks of proton and

β-ray coincidently in a wire chamber. Under the condition that the parameters of the wire chamber are
optimized to the β-ray detection, the output linearity for protons is crucially suffered from gain reduction
due to the space charge effect. In order to collect the desirable events correctly, it is necessary to obtain thegain reduction factor s based on a phenomenological model.
A gain reduction model was previously proposed taking into account the self-induced space charge effect[1], whereas the experimental verification of the model has been still required. In the model, s is expressed
as follows,s ≡log 1 + f G0
f G0

dE
dl

dE
dl

,

(1)

where f is a constant factor including all microscopic characteristics of the space charge effect, which
determines the absolute scale of gain reduction, G0 is the multiplication factor without the space charge
effect, dE/dl is energy loss per wire length. Actually, dE/dl depends on the geometry of the wire and the
projectile directions. G0 is determined by energy calibration using 55Fe X-rays. The factor f is treated here
as a fitting parameter since it is hard to calculate it analytically.
In this study, a multi-wire drift chamber (MWDC) filled with a mixed gas of He and CO2 was irradiatedby a proton beam from the Tandetron accelerator at UTTAC. The proton beam energy Ep, the applied anodewire voltage V0, and the angle of the proton beam direction relative to the anode wires of the MWDC, φ,
were changed as experimental parameters. The dependence of s on these parameters is compared with that
expected by the model.

Fig. 2. Combined results of the optimum f values.

Fig. 1. The schematic layout of the MWDC.

1
2

Graduate School of Science, University of Tokyo
International Center for Elementary Particle Physics, University of Tokyo

37

Figure 1 shows the overall structure of the MWDC, which has a dimension of 13 cm × 13 cm × 6 cm.
It is made of G10 FR-4, or glass-epoxy laminate, and is housed in a 14 L vacuum chamber filled with 85
kPa He gas and 15 kPa CO2 gas. Electrons created by ionization of the gas are drifted by an electric fieldof 4 × 102 V/cm in the y-direction, towards the multi-wire region located in the upper part of the MWDC.
The output pulse heights for the proton beam were initially measured at a multiplication factor of about
3

10 by tuning the anode voltage. The results were compared with those obtained from the Geant4-basedMonte Carlo simulation [2] assuming the same MWDC geometry. It is successfully confirmed that theexperimental distributions for the different beam energies can be reproduced by the simulations under theconditions of the “low enough” multiplication factors quantitatively.
The output pulse heights for the proton beam obtained with a high multiplication factor (~104) were thencompared with the energy deposition calculated by the simulations. The data were taken with changing φfrom 40 to 90◦ at an interval of 10◦ to find the dependence on dE/dl. In this way, s was derived as the ratioof the experimental output pulse height with respect to the simulation results without gain reduction effect.
The value was compared with the results of simulations with the gain reduction model with sweeping f as afree parameter. The f value that minimizes χ2/ndf was selected as the optimum value.
Figure 2 shows the result of the derived f values for different values of Ep and V0. The f values seems to
be a constant within the present uncertainties. The comparison of the experimental energy deposit
distributions before and after correcting for the space charge effect is shown in Fig. 3, together with those
calculated by the simulation. The energy deposit distributions corrected by the space charge effect based on
the proposed model agree well with the simulation results. Thus the space charge effect can be included
certainly, once an appropriate f value is found and is well scaled with the relative difference of the angles
between the wire and projectile directions. For details, see Ref. [3].

Fig. 3. The experimental energy deposit distributions with and without the correction of
the gain reduction for φ=90º (left) and 60º (right), together with the simulation results.

References[1] Y.Arimoto et al., Nucl. Instr. Meth. Phys. Res. A 799 (2015) 187.
[2] S. Agostinelli et al., Nucl. Instr. Meth. Phys. Res. A 506 (2003) 250.
[3] N. Nagakura et al., Prog. Theor. Exp. Phys. 013C01 (2018).

38

4.7

Quantitative micro-PIXE analyses of trace elements in sphalerite fromhydrothermally-altered sediments

M. Kurosawa, K. Ikehata, K. Hattori, K. Sasa, S. Ishii
Sphalerite, a cubic form of ZnS (β-ZnS), is the most common zinc ore mineral and is widespread inhydrothermally altered rocks [1]. A chemical property of sphalerite is a deviation from stoichiometry in
ZnS. Also, small cation vacancies (less than 1 atom %) have been observed [1]. In addition, natural
sphalerites contain Fe, Mn, Cd, Co, Se, and Hg at a concentration levels of several tens to thousands parts
per million weight (wt. ppm) [1‒5]. Another trace impurities of Ti, Cu, Sb, Sn, In, Ag, As, Ga, Ge, Ni, Ba,
Mo, V, and Cr have been also reported in natural samples [1‒5], so that sphalerite is the major source
material of Cd, In, Ge, and Ga [1]. Since concentration levels of the minor and trace heavy-elements are
considered to be very close to hydrothermal conditions, these contents have been frequently analyzed to
examine formation processes of hydrothermally-altered rocks and hydrothermal ore deposits [1‒5]. For
these reasons, we analyzed major to trace elements in sphalerites from deep sea-floor sediments altered byhydrothermal activities to examine a heavy-metal condensation by the same activities.
Determination of trace elements can be usually performed by using particle-induced X-ray emission(PIXE), reported here, and laser-ablation inductively-coupled plasma mass spectrometry (LA‒ICP‒MS)[2‒5]. The sphalerite samples for PIXE were collected from drilling core samples of thick sea-floor clay
sediments near an active hydrothermal field at Iheya-North-Knoll in the Okinawa Trough back-arc basin,
Japan [6]. The sediments consisted mainly of clay minerals including Mg, Na, K, and Ca and contained
small amounts of secondary minerals formed by the hydrothermal activities [6]. The present samples werea few millimeter-sized and polygonal-shaped crystals with no visible inclusions of their secondary
minerals. The sample surfaces were polished and were coated with a carbon film to prevent electrostatic
charging.
PIXE analyses were performed at the 1MV Tandetron accelerator. A 0.1 to 0.3 nA beam of 1.92-MeV
proton was focused to a 26 × 26 μm2 to 33 × 36 μm2 spot on the sample using slits and magnetic lenses.
The beam was incident perpendicularly on the sample surface, and the X-ray measurement take-off angle
was 45˚ [7]. The characteristic X-rays excited by the incident beam were collected by the Si(Li)
X-ray-energy detector with a nominal resolution of 137 eV at 5.9 keV. Since measurements of intense
X-rays from S and Zn were required to examine the stoichiometry in ZnS, we used a 55-μm-thick Mylar
filter to prevent the entry into the detector of protons scattered from samples. The total charge wasdetermined by integrating the target currents, and all samples were analyzed to the integrated charges of
0.05 to 0.25 μC. Analytical points were chosen based on optical viewing using a CCD camera mounted on
the microscope. Quantification of the PIXE analyses was performed based on the model of Kurosawa et al.
[7]. Secondary fluorescence effect was corrected by the method of Reuter et al. [8].
PIXE spectra of the sphalerite samples consist mainly of intense K X-ray peaks from S and Zn, andtheir pile-up and escape peaks as shown in Fig. 1. The spectra show K X-ray peaks from Mn, Fe, Co, Ni,
and Cu, and L X-ray peaks from Cd and Pb. These elements are major impurities in the present sphalerite

39

samples. There is no significant peak overlap

Zn

105 S

between the escape and pile-up peaks and L X-ray
peaks from important impurities (Cd and Pb) inimpurities (Ag, In, Sn, Sb, Ga, Ge, As, and Se),
although they are absent in the present case, would
not be affected by the escape and pile-up peaks.
Element concentrations of the sphalerite (Fig. 1),
determined by PIXE, were as follows: 60.45 wt.%

Intensity (cts)sphalerite. L X-ray peaks from another important

104
Mn

103

sediments. These minor and trace-element contents

Pb

Cr

p1 Pb

Cd

102

Co Ni
+
e1

2

0.139 wt.% for Cd, 440 ppm for Co, 420 ppm for Ni,

another sphalerite samples from the present alteredFe

Cd

wt.% for Cu, 0.550 wt.% for Mn, 0.495 wt.% for Pb,

except for Pb, were almost the same as those ofCu

Cd

for Zn, 32.83 wt.% for S, 2.760 wt.% for Fe, 1.848

and 210 ppm for Cr. These contents of element,

Zn

Fe

p2
Pb

6
10
14
X-ray energy (keV)

18

Fig. 1. PIXE spectrum of sphalerite in alteredsea-floor sediments. Escape and pile-up peaks are
identified as follows: e1 (escape peak of Zn Kα), p1(pile-up peak of S Kα+Zn Kα), and p2 (pile-up peakof Zn Kα+Zn Kα).

almost agreed with those from sphalerites in sea-floor hydrothermal ore deposits. [2, 5]. Detection of thepresent high Pb contents may be due to microscopic or invisible inclusions of galena (PbS) [4].
A chemical formula of the sphalerite (Fig. 1) is (Zn0.903Fe0.048Cu0.028 Mn0.010Pb0.002Cd0.001
Co0.001Ni0.001)0.994S1.000, indicating the stoichiometry of ZnS composition. Most of the sphalerite samples
demonstrated similar stoichiometry with slight cation deficiencies, indicating that the hydrothermal
activities (<500 °C) do not affect the stoichiometry of sphalerite.
In summary, the present PIXE analyses demonstrated that chemical compositions of sphalerites fromthe present altered sediments were very similar, except for Pb. No large cation deficiency(non-stoichiometry) associated with the hydrothermal activities were also observed in the sphalerite. These
data imply that sphalerites from the surveyed area lack a chemical feature indicative of hydrothermal
activity related to ore deposit formation. In the future work, it may be important to explore possibility ofthe sphalerites as a source material for the elements (Cd, In, Ge, and Ga) of industrial importance.
References[1] J. F. W. Bowles et al., Rock Forming Minerals. Vol. 5A, Non-Silicates: Oxides, Hydroxides andSulphides, The Geological Society of London, London (2011) p418.
[2] D. Huston et al., Econ. Geol. 90 (1995) 1167.
[3] S. Murao et al, Nucl. Instr. Meth. Phys. Res. B 109/110 (2008) 627.
[4] N. Cook et al., Geochim. Cosmochim. Acta 73 (2009) 4761.
[5] J. Lockington et al, Miner. Petrol. 108 (2014) 873.
[6] Y. Miyoshi et al., Resour. Geol. 65 (2015) 346.
[7] M. Kurosawa et al., Nucl. Instr. Meth. Phys. Res. B 266 (2008) 3633.
[8] W. Reuter et al., J. Appl. Phys. 46 (1975) 3194.

40

4.8

Preliminary report on micro-PIXE analysis of trace Ni in single fluidinclusions from a miarolitic quartz at Tsushima granite

M. Kurosawa, K. Sasa, S. Ishii
Nickel is an abundant element in the Earth’s mantle and core, and the abundance in the primitive
mantle (2000 ppm) is twenty times higher than that in the bulk continental crust [1]. Thus, mafic magmas
derived from the mantle normally contain high concentration of Ni. Whereas, Ni abundances in granitic
rocks are relatively low (9‒17 ppm; [1]), and accordingly, nickel minerals are rare in granitic rocks andhydrothermal veins related to granites. There is also no detection of trace Ni in fluid inclusions from
granitic rocks and the hydrothermal veins. Some nickel sulfide minerals, however, have been sometimes
observed from hydrothermal ore veins in or near granites [2‒6], and the origin of Ni remains as an issue tobe solved [5]. In most cases, the origin might be ascribed to contaminations of Ni leached from thesurrounding mafic rocks [5] or sedimentary rocks [6], but a possibility of purely granitic-magma origin
still remains [2, 4]. In this report, we describe the first observation of trace Ni in fluid inclusions from amiarolitic quartz at Tsushima granite with the purely magmatic origin [7].
A quartz crystal including fluid inclusions wascollected from a miarolitic cavity in biotite granite at
Uchiyama, the Tsushima islands, Nagasaki Prefecture,
Japan [8]. The quartz crystal contains many polyphaseand vapor-rich fluid inclusions formed by brine-vapor
separation due to fluid boiling (Fig. 1). Subordinate
two-phase aqueous inclusions, trace amount of liquid
CO2 and aqueous liquid-rich inclusions were also
observed in the quartz crystal [8]. A considerable amountof Ni were detected in some vapor-rich and polyphasefluid inclusions from the miarolitic quartz. Salinities ofthe vapor-rich inclusions were mainly of 0.5‒2.2 wt.%

Fig. 1. Photomicrograph of polyphase andvapor-rich fluid inclusions in a quartz crystal
from miarolitic cavity at Tsushima granite. A
large inclusion on the left side is a polyphaseinclusion, 70 μm in size, with a bubble (darkellipsoidal) and many daughter crystals of halite,
FeCl2 and so on. Several ellipsoids in the rightside are vapor-rich inclusions.

NaCl equivalent. The vapor-rich and polyphase inclusions were typically 30‒60 μm in size, ellipsoidal or
negative-crystal shapes, and the inclusion depths were less than 10 μm. The quartz-crystal samples were
cut and polished, and then the surface was coated with a carbon film to prevent electrostatic charging.
The procedure for PIXE analysis is noted briefly here since the details are described in §4.7 of thisAnnual Report. A 1.0 to 2.0 nA beam of 1.92-MeV proton was focused to ~50 ×50 μm2 spot on the sample.
A filter of 55-μm-thick Mylar film was used for the X-ray detector not only to prevent the stray protons,
but also to attenuate the intense X-rays from the predominant light elements. All samples were analyzed
for irradiation of 1.92-MeV H+ with integrated charge of 2.0 μC. In the present analysis, the correction of
the secondary fluorescence effect amounts to only less than a few % for most of the elements.
The PIXE spectrum of a vapor-rich fluid inclusion from the miarolitic cavity consists of K X-ray peaks
from Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, and Br, and of L X-ray peaks from Pb (Fig. 2). Most of41

vapor-rich inclusions from the miarolitic cavity demonstrates similar X-ray spectra. Element
concentrations of the vapor-rich inclusion determined by the PIXE data are as follows: 3325 ppm for Cl,
2301 ppm for K, 1884 ppm for Fe, 1720 ppm for Ca, 111 ppm for Mn, 82 ppm for Zn, 60 ppm for Pb, 38
ppm for Ni, 24 ppm for Cu, and 3 ppm for Br. Most of the vapor-rich inclusions contain about 5‒30 ppm
Ni. The polyphase inclusions also contain Ni of 5 to 50 ppm. These are the first observation of trace Ni in
fluid inclusions from granite-related rocks.
Miarolitic cavities in granite are void spaces

104with outlines shaped by large quartz and feldspar

Si K Ca

crystals and are commonly formed by entrapment ofCl

fluid separated from granitic magma duringof trace Ni in the fluid inclusions indicates thepresence of Ni in hydrothermal fluids originallyreleased from the granite. In northern Tsushima,Ni-containing sulfide minerals have been sometimes

Intensity (cts)solidification of the granite [8]. Thus, the detection

103

S

Al

Fe

Ca

Ti

Mn

102

Ni Zn
Cu

10

1

Cu

reported from hydrothermal ore veins related to the
Tsushima granite [2, 4]. The Ni source seems to behydrothermal fluids from the granite [4]. The

100

2

present Ni detection in fluid inclusions from themiarolitic quartz supports the granitic magma originof Ni.

Fe

12

Fig. 2. PIXE spectrum of vapor-rich fluid inclusions inquartz crystal from miarolitic cavity at the Tsushima
granite, Japan.

[1] S. R. Taylor and S. M. McLennan, The Continental Crust: Its Composition and Evolution,
Blackwell Scientific, Oxford. 1985.
[2] N. Shimada and Y. Watanabe, Sci. Rep. Dep. Geol. Kyushu Univ. 11 (1973) 225.
[3] Y. Shiga, Mining Geol. 25 (1975) 27.
[4] N. Shimada, Mem. Fac. Sci., Kyushu Univ. Ser. D 23 (1977) 417.
[5] Y. Shiga, Mining Geol. 33 (1983) 385.
[6] N. Jackson et al., Econ. Geol. 84 (1989) 1101.
[7] K. Shin et al., Res. Geol., 59 (2009) 25.
[8] M. Kurosawa et al., Geochim. Cosmochim. Acta 182 (2016) 216.
[9] M. Kurosawa et al., Nucl. Instr. Meth. Phys. Res. B 266 (2008) 3633.

42

Pb Pb
Br

4
6
8
10
X-ray energy (keV)

References[10] W. Reuter et al., J. Appl. Phys. 46 (1975) 3194.

Zn

4.9

Physico-chemical properties of active layers controlling the boric acidrejection by polyamide composite reverse osmosis and nanofiltration
membranes

R. Tanaka1, M. Niinae1, T. Suzuki1
State-of-the-art thin-film composite reverse osmosis (RO) and nanofiltration (NF) membranes consist ofa nonwoven polyester layer (~50−150 μm) that backs an intermediate layer of polysulfone (~20−50 μm),
which in turn supports an active layer of polyamide (< 100 nm) [1]. Among these three layers, theperformance of the membrane was mainly determined by a polyamide active layer [2]. However, it iswell-documented in the literatures [3, 4] that neutral and small molecules including H3BO3 are poorly
rejected by state-of-the-art RO/NF membranes. Therefore, the objective of this study is to investigate
physico-chemical properties of active layers controlling the boric acid (H3BO3) rejection by polyamide
composite reverse osmosis and nanofiltration membranes. To achieve this objective, we measured theconcentration of deprotonated carboxy group (R-COO-) of polyamide active layer of 6 commercial RO/NF
membranes by probing R-COO- with Ag+ and quantifying the Ag+ using Rutherford backscattering
spectrometry.
All solutions were prepared using distilled deionized water with a resistivity greater than 18 MΩ cm(WA200, Yamato Scientific Co., Ltd., Tokyo, Japan). All reagents were purchased at guaranteed reagent
grade quality from Nacalai Tesque, Inc. (Kyoto, Japan) or Wako Pure Chemical Industries, Ltd. (Osaka,
Japan) and used without further purification. Saturation of R-COO- with Ag+ at pH6.0 and 10.0 was
performed according to the procedures reported in the literature [5]. Permeation experiments were
performed with a cross-flow, closed-loop filtration system similar to that described in the literature [1].
The system had two flat-leaf cells in series and each cell had 155 cm2 effective filtration area. The system
was always operated at constant feed solution temperature of 24 ± 0.3oC and pH = 6.0. For performance
evaluation, the membrane samples were initially stabilized for three weeks at 2.5 MPa to allow for
membrane compaction, using a feed solution containing 141 mM NaCl and 1.85 mM H3BO3.
Representative RBS spectra obtained for (a) polysulfone support and commercial RO membrane (M1),and (c) Ag+-treated M1 membranes at pH6.0 and pH10.0 are shown in Fig. 1. Also shown are the fitted
spectra obtained by using the software SIMNRA. Obviously, the Ag+ peak is higher at pH10.0 than at
pH6.0, which means that more fraction of R-COOH is deprotonated at higher pH. Next, we investigated
the relationship between physico-chemical parameters obtained from charge density analysis (i.e., R-COOconcentrations at pH6.0 and pH10.0) and water/H3BO3 transport parameters obtained by modelingexperimental data using the solution-diffusion model allowing for the existence of unhindered advection
through nano-scale imperfections. However, as shown in Fig. 2 as an example, we could not find strong
correlation between these values.

1 Yamaguchi University

43

1500

Yield（counts)

1200

Fig. 1. Representative RBS spectra obtained for (a)Polysulfone support layer
SIMNRA fitting
Virgin M1
SIMNRA fittingC

polysulfone support and M1 membranes, and (b)Ag+- treated M1 membrane at pH6.0 and pH10.0.

900

The H/C ratio for M1 membrane was assumed to beN

600

0.67 (value for fully aromatic polyamide). The

O

average

S

300

(a)

distribution

Cl

0

Yield（counts)

standardof

activedeviation
layer

in

Gamma

thicknesswere

determined from the nitrogen peak, oxygen peak,
and the energy shift of the frontal peak of sulfur.

900
Ag+- treated M1 (pH 6.0)
SIMNRA fitting
Ag+- treated M1 (pH 10.0)
SIMNRA fitting

600

300

0

Ag

(b)
0.4

B×δPA (m2/day)

and0.6 0.8 1.0 1.2 1.4 1.6
Backscattered He energy [MeV]

1.8

5e-8

Fig. 2. Relationship between physico-chemical

4e-8

parameters obtained from charge density analysis
and water/H3BO3 transport parameters obtained by

3e-8

modeling

2e-8experimental

data

using

the

solution-diffusion model allowing for the existence

1e-8

of

0

imperfections.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

CR-COO- at pH 10.0 (mol/L)

References[1] T. Suzuki et al., Water Res. 100 (2016) 326.
[2] R. J. Petersen, J. Membr. Sci. 83 (1993) 81.
[3] B. Van der Bruggen et al., Water Res. 36 (2002) 1360.
[4] Y. Sato et al., Water Res. 36 (2002) 3371.
[5] O. Coronell et al., Environ. Sci. Technol. 45 (2011) 4513.

44

unhindered

advection

throughnano-scale

4.10

Thermoelectric SiGe film synthesized on a flexible plastic substrate

K. Toko, T. Suemasu
A composition tunable Si1-xGex alloy has a wide range of applications, for example, to thermoelectric
devices. We investigate the Al-induced layer exchange (ALILE) growth of Si1-xGex on an insulator (SGOI).
Preparation of the bilayered amorphous (a-) Si1-xGex and Al of 50 nm thickness each on a SiO2 glass
substrate was performed at room temperature using radio frequency (RF) magnetron sputtering (basepressure: 3.0 × 10-4 Pa) with Ar plasma. The RF power was set to 50 W for all of the Si1-xGex targets. The
Ge compositions x in the prepared a-Si1-xGex layers were determined to be 0, 0.15, 0.3, 0.6, 0.8, and 1 by
Rutherford backscattering spectrometry (RBS). Between the two deposition cycles, the Al film was
exposed to air for 30 min to form a native Al oxide layer as a diffusion-limiting layer. The samples werethen annealed at 340–450°C in a N2 ambient chamber with an in-situ optical microscopy system until thelayer exchange was finished. The Al and AlOx layers were then etched away with HF solution (HF: 1.5%)
for 1 min.
The effect of the Ge fraction x in Si1−xGex on layer exchange temperature range was examined. The
higher the value of x, the lower the temperature range wherein the layer exchange occurred. This isindicative of the activation energy required for crystallization. Furthermore, the hole concentration p
increased with increasing x and growth temperature. The variation of electrical conductivity σ withincreasing x was observed to be directly proportional to p. Contrarily, there was no detectable variation of
σ with respect to the growth temperature. Such observed behavior could be due to the balance between p
and crystal quality because the grain size increases with decreasing growth temperature in ALILE. The
electrical conductivities of the Si and Ge layers approached to those of bulk single crystals within one
order of magnitude, despite these layers being polycrystalline. Such high σ may be attributed to the large
grains, i.e., a few grain boundaries, in the ALILE grown layers. These results mean that p and σ can becontrolled by adjusting x and the annealing temperature. The Seebeck coefficient S decreased withincreasing p and x, which is a well-known phenomenon in SiGe. Here, S can be determined using thefollowing equation:

where kB is the Boltzmann constant, q is the elementary charge, p0 is a constant given afterwards by eq. (2),and δ is a constant ≈ 1. This equation clearly illustrates the relationship between p and S. Furthermore, p0
can be expressed as:

where m is the effective mass of the hole, T is the absolute temperature, and ℏ is Dirac’s constant. For
Si1−xGex, m decreases as x increases. Therefore, from eqs. (1) and (2), it can be deduced that S decreases
with an increase in x. The power factor P = S2σ at room temperature (RT) increased with an increasing p

45

for x ≥ 0.8, and the opposite trend was observed for x ≤ 0.6. It is generally observed for SiGe that P
improves as p approaches the order of 1020 cm−3, and this is attributed to the increase in σ. Conversely, theobserved grain size increasing with a decrease in growth temperature for ALILE-SiGe is responsible forthe increase in σ. Therefore, the behavior of P for x ≤ 0.6 could be highly attributed to the enlargement ofgrains due to low temperature growth. The maximum P of 430 µW/mK2 was recorded for x = 1. By
assuming a ĸ (thermal conductivity) value for 100-nm-thick SiGe films, the dimensionless figure of merit
ZT was determined. In relative terms, ZT was observed to be maximum at x = 0.6. Therefore, for ALILE
processed SiGe thermoelectric devices, x = 0.6 could be considered to be the optimum composition.
Since the growth temperature (350°C) of Si0.4Ge0.6 is lower than the heat resistance temperature of theplastic (polyimide) substrate, we developed ALILE-Si0.4Ge0.6 on a SiO2-covered polyimide substrate. The
processed Si0.4Ge0.6 films were of high quality as evidenced by the absence of cracks on the sample surface
and a relatively high degree of film uniformity over the entire substrate. From the Hall effect measurement
p was determined to be 5.8 × 1019 cm−3 and hence σ = 157 S/cm. Thus, we have achieved the growth of
Si0.4Ge0.6 on a plastic substrate, though σ is slightly lower than those of the previous glass substrates. Thismay be due to the fact that the sample with a plastic substrate has a smaller grain size and higher p thanthose of glass. For the Si0.4Ge0.6 samples on a plastic substrate, P at RT is estimated to be 190 µW/mK2.
Although this value is about half of those of the Si0.4Ge0.6 samples on glass, it is the highest level among
thermoelectric films synthesized directly on a flexible plastic substrate.
SiGe generally requires high processing temperatures to obtain high values of P mainly because hightemperatures are required to activate impurities contained. The ALILE technique enabled us to achieveboth high P ( > 400 µW/mK2) and low processing temperatures (< 400°C). The main reason for thisachievement could be described as follows: for the Si and Ge layers, secondary ion mass spectrometry
indicated that the Al concentrations in these two layers were of the same order as that of p. In addition,
each of the amount of Al atoms in Si and Ge was almost equal to the solubility limit. These results suggestthat the hole concentration in the Si1−xGex layers is determined by the solubility limit of Al in Si1−xGex.
Since the solubility limit increases with increasing temperature, this model accounts for the growthtemperature dependence of p in the Si1−xGex layers. Therefore, it could be implied that the advantage of themetal-induced layer exchange is not only crystallizing SiGe at low temperatures but also doping andactivating impurities in a self-organizing manner during growth.
In conclusion, we demonstrated that SiGe formed by ALILE on insulating substrates has excellent
characteristics as a thermoelectric film while maintaining low process temperatures ( ≤ 400°C). The SiGe
layers introduce Al atoms to the solid solubility limit during growth, so that they are selforganically-highly-hole-doped without high-temperature-activation annealing. With this feature, a highpower factor (430 µW/mK2) and a low process temperature are simultaneously achieved. Furthermore, wedeveloped the Si0.4Ge0.6 layer on a plastic substrate and obtained a power factor of 190 µW/mK2. Thisvalue is the highest level among most thermoelectric films that are directly grown on a plastic substrate.
The technology developed in this study is a promising candidate for its use in next-generation flexible
thermoelectric devices.
The authors are grateful to Dr. D. Sekiba of UTTAC for RBS analyses.

46

4.11

Development of T-ERDA method for sensitive hydrogen-profiling

H. Naramoto, M. Sataka, H. Kudo, A. Yamazaki, K. Sasa
Interstitial hydrogen atoms can be incorporated into metals beyond the solubility limit by forming
agglomerates with atomic defects under the defect-generation process. These agglomerates induce theserious deterioration on ductility in less-hydrogen soluble materials typically [1] and it is essential to know
the 3-dimensional distribution of agglomerates in the materials. The hydrogen-recoiling resulting from thenuclear elastic scattering of the broad resonance type [2] is contributable for this purpose. Actually, for
ten-MeV He on H the recoil cross section at ~0° is extremely larger than in the Rutherford case, forexample, by a factor of up to 380. In this study, the angle-sensitive features of the transmission ERDA
method are characterized for developing a more sensitive/reliable hydrogen-detection method.
Figure 1 shows the hydrogen recoil spectra for the uncalibarated detection angles, of which the origin
must be determined precisely, under the normal incidence of 8 MeV 4He2+ ions to the layered model film.
Two recoil peaks at higher and lower channels correspond to two Mylar films separated by Al film at the
1st and the 3rd layer, respectively. The half-width of the 2nd recoil peak is wider by 35% than that of the
1st one because of the energy-straggling of incident 4He ions when passing through the Al interlayer. The
ratio of the 2nd to the 1st peak area, 0.74, can be accounted for in terms of the ratio of recoil cross-sections
at the two layers, 0.81. One can see the symmetric shifts of hydrogen recoil peaks to the lower channel
centering around +3.2° together with the broadening and the intensity decrease of the recoil peaks.
From Fig. 1, the recoil peak positions are plotted as a function of the uncalibarated detection angles inFig. 2. The angular dependence is fitted with the expression of “Acos2θ-B(dE/dX)/cosθ” considering therecoil kinetics and the followed energy loss of recoil protons as guided by a red solid curve, where A and
B are constants, θ is the recoil angle (which of course equals to the calibrated detection angle), and(dE/dX)

expresses

thestopping power. In therelevant energy region,(dE/dX) in Al can beapproximated to be a
linear function of the
proton travel distance (X).
From the fitting, +3.13°
should be taken as thecalibrated

0°

in

the

detector rotating system.
Judgingfromtheevaluated

data,

the

angular

range

of

±4°

around the calibrated 0°

Fig. 1. Hydrogen recoil spectra for uncalibrated detection angles (nominal ones)
under the normal incidence of 8 MeV 4He2+ ions on the layered model film.

47

can be employed for the depth-sensitive hydrogen profiling without degrading the energy resolution. For
the detailed hydrogen profiling, it is also important to set up the surface normal condition using theanalysis beam. The calibration with a shift of 3.46° in the rotation angle of sample-stage was made byanalyzing a series of spectra taken at the calibrated detection angle, i.e., the recoil angle of 0° .
Following the angle calibration procedure described, T-ERDA spectra of hydrogen adsorbed on
as-rolled Al film surface were taken at three different energies covering the large recoil cross-sections. The
hydrogen recoil intensities without background for 8, 9 and 10 MeV 4He2+ ions reasonably correspond tothe cross-sections for the nuclear elastic collisions at the relevant energies, but one can see the complicatedbackground structure. In Al, the background seems to be originated from the two kinds of sources: 1) thehigh intensity background with the decaying nature in the lower energy region, and 2) the backgroundwith the prompt nature in the high energy region. Judging from the higher signal/noise ratio, 8 MeV 4He2+
ions are suitable for the sensitive analysis. The recoil peak energy for 8 MeV 4He2+ ions is close to thebackground tail but the situation can be improved by decreasing the Al thickness.
In conclusion, the precise angle-calibration procedure developed can be applied at each set of machinetimes, which enables reliable hydrogen profiling with the improved sensitivity and without degrading theenergy resolution. The allowed acceptance of the ±4° recoil angle can be effectively employed for the
3-dimensional hydrogen-profiling combined with the microbeam-scanning. In general, hydrogen detection
in a deeper layer requires higher-energy projectiles. Practically, we may use nuclear elastic collisions of
He at 8-11 MeV, as is demonstrated in Fig. 3. For sophisticated T-ERDA, it is required to make a suitablechoice of the analysis beam energy and the sample thickness depending on sample species.

Fig. 2. Recoil peak positions as a function of
the uncalibrated detection angle under thenormal incidence of analysis beam. The data
were fitted considering the recoil kinetics andthe energy loss process of recoil protons.

Fig. 3. T-ERDA spectra detected at the 0º recoil angle under
the normal incidence of 8, 9, and 10 MeV 4He2+ ions on the
as-rolled Al film (170 μm). The recoil yields in the spectra arenormalized to the accumulated charge of 10 μC.

References[1] For example: S. Lynch, Corrosion Reviews 30 (2012) 105.
[2] For example: A. H. Bott et al., Surface and Coating Technology 70 (1995) 257.

48

4.12

Epitaxial strain-induced enhancement of low-temperature topotactichydrogen substitution reaction of SrTiO3

D. Kutsuzawa1, Y. Hirose1, D. Sekiba
Recently, oxyhydrides have been intensively studied because of their unique physical and/or chemical
properties. For example, hydride (H−) ions in perovskite-type ATiOxHy (A = Ca, Sr, Ba) are highly labile,which enables low-temperature anion exchange reaction, such as H−/D−, H−/O2−, H−/N3−, etc. [1]. These
oxyhydrides are also expected as catalysts for synthesis of NH3. Thus far, transition metal oxyhydrides
have been synthesized by low temperature topotactic hydrogen substitution of precursor oxides using
metal hydrides (e.g. CaH2) or high temperature high pressure reactions. The former has the advantage that
it is applicable to precursor oxides not only in a fine powder form but also in an epitaxial thin film form,
producing single-crystal like thin samples suitable for measuring the materials’ intrinsic electricaltransport properties. Another intriguing feature of epitaxial thin films is that their physical and/or chemical
properties can be modified by epitaxial strain, as reported in various materials.
In this study, we synthesized SrTiOxHy epitaxial thin films on various substrates by topotactichydrogen substitution to examine the effect of epitaxial strain on the hydrogen content y. A quantitative
analysis of the anion compositions by combination of Elastic Recoil Detection Analysis (ERDA) and
Rutherford Backscattering Spectrometry (RBS) revealed that much hydrogen can be incorporated in thetensile-strained precursor SrTiO3 film.
SrTiOxHy thin films were prepared by a topotactic reaction reported previously [2]: First, precursor
SrTiO3 epitaxial thin films were grown on the following three single crystalline substrates with different
lattice mismatch values f = (asub−afilm)/afilm, where asub and afilm are the in-plane lattice constants of thesubstrate and the film (SrTiO3; 3.905 Å), respectively; namely on the (001) plane of LaSrAlO4 (LSAO)(tetragonal, asub = 3.75 Å, f = −4.0%), the (001) plane of LSAT (cubic, asub = 3.87 Å, f = −0.90%), and the(110) plane of DyScO3 (DSO) (orthorhombic, asub = 3.94 Å under pseudo-cubic approximation, f =+0.89%) by pulsed laser deposition method. The crystal structure of the films was evaluated by XRD. The
hydrogen amounts in the films were determined by ERDA using a 2.5 MeV 4He2+ beam obtained from the
1MV Tandetron accelerator at UTTAC. The oxygen amounts in the films were evaluated by energy
dispersive X-ray spectroscopy equipped with a scanning electron microscope (SEM-EDX) andcross-checked by heavy ion ERDA with a 38.4 MeV 35Cl7+ beam performed using a 5 MV electrostatic
tandem accelerator at MALT, University of Tokyo. In both the SEM-EDX and 35Cl-ERDA measurements,
a SrTiO3 precursor film was used as the standard for the amount of oxygen in a film.
Figure 1(a) shows 4He-ERDA spectra of the tensile-strained SrTiO3/DSO films before and after the
CaH2 treatment. The precursor films show a weak hydrogen peak at ~400 channel originating from surface
adsorbed water. The peak intensity of hydrogen significantly increased after the CaH2 treatment andbecame stronger with increasing reaction time. Accompanied by this increased amount of hydrogen, a

1

The University of Tokyo

49

decreased amount of oxygen was also observed by
SEM-EDX, shown in Fig. 1(b), as well as by
35

Cl-ERDA, shown in Fig. 1(c). The decrease of theoxygen amount x and the increase of y in the
SrTiOxHy films are almost balanced within theexperimental uncertainty (Fig. 1d), proving that
substitution of hydrogen for oxygen occurred aspreviously reported for SrTiO3/LSAT epitaxial thinfilms [2]. The substitution of hydrogen for oxygen
was also confirmed in the SrTiO3/LSAT and
SrTiO3/LSAO films after CaH2 treatment (Fig. 1d).
Notably, the amount of substituted hydrogen, i.e., ystrongly depends on the substrates: the largest y is
obtained by the tensile-strained SrTiOxHy/DSO films,
followed by the almost relaxed SrTiOxHy/LSAO films,
andsubsequently

by

the

compressive-strained

SrTiOxHy/LSAT films.
The hydrogen substitution reaction consists of two

Fig. 1. (a) 4He-ERDA spectra of the SrTiO3/DSO films
before and after CaH2 treatment. (b) SEM-EDX spectraof the SrTiO3/DSO before and after the CaH2 treatment.
(c) 35Cl-ERDA spectra of oxygen recoils reconstructedfrom ΔE-E histogram of the SrTiO3/DSO before and after
the CaH2 treatment. (d) Oxygen amount x, hydrogenamount y, and total anion amount x + y in the SrTiOxHy
films on the three kinds of substrates after the CaH2
treatment.

steps, the H−/O2− exchange at the surface and anion
diffusion inside the film. We considered that the epitaxial strain affects the ionic diffusion in the films, asreported in various materials. It is reasonable to assume that diffusion of O2− limits the reaction rate, since
the diffusion of divalent O2− is generally slower than that of monovalent H− owing to stronger electrostaticinteractions. Recent theoretical calculations on the O2− diffusion in SrTiO3 predicted that both the in-planeand out-of-plane diffusion of O2− are enhanced by in-plane tensile strain [3], whereas the out-of-plane
diffusion of O2− is suppressed by in-plane compressive strain [4], supporting our hypothesis.
In conclusion, we revealed that the amount of substituted hydrogen is enhanced in tensile-strained
SrTiOxHy/DSO films, probably owing to the promotion of oxygen diffusion. These results demonstrate thepossibility for strain-engineering the chemical and physical properties of metal oxyhydrides.
References[1] K. Masuda et al., J. Am. Chem. Soc. 137 (2015) 15315.
[2] T. Yajima et al., J. Am. Chem. Soc. 134 (2012) 8782.
[3] R. AL-Hamadany et al., J. Appl. Phys. 113 (2013) 224108.
[4] R. Al-Hamadany et al., J. Appl. Phys. 113 (2013) 024108.

50

4.13

Room and helium temperature Mössbauer experiments on Co-Ni ferrites
to assess effect of synthesis method on magnetic properties

S. Sharmin, M. Kishimoto, H. Latiff, H. Yanagihara, E. Kita

Magnetic particles with a size on the order of several nanometers may exhibit superparamagnetic
properties. The nanoparticles of metal oxides such as spinel ferrites possess great potentials for applications
since they are relatively inert and their magnetic properties can be fine-tuned by chemical manipulation [1].
The aim of the present study was to characterize using Mössbauer spectroscopy the magnetic properties of CoNi ferrite nanoparticles synthesized by the successive methods of chemical co-precipitation, hydrothermal
treatment, and etching in hydrochloric acid (HCl). A static measurement, such as magnetic susceptibility, sees
the collective behaviors of paramagnetic clusters, while the Mössbauer effect can see the behavior of theindividual species within a cluster [1].
In a typical synthesis method, 0.02 mole of FeCl3-H2O, 0.005 mole of CoCl2, and 0.003 mole of NiCl2(Wako Pure Chemical Industries, Ltd, 99.0% purity) were dissolved in 20 mL of distilled water, to obtain a 2.5
times molar ratio of Fe3+ against (Co2+ + Ni2+). The samples produced by chemical co-precipitation and thenhydrothermal treatment are denoted by AP and HT respectively, while the samples produced as a result of
etching after hydrothermal treatment are indicated by ET2 (HCl solution 2.0 mole/L), ET4 (4.0 mole/L), andET6 (6.0 mole/L). The Mössbauer spectra of the samples were recorded in transmission geometry at room
temperature (RT) and liquid helium temperature of 4.2 K (LT) using a 57Co/Rh source.
The Mössbauer spectra collected for the AP sample (with diameter of only a few nanometers) at RT and
4.2 K are shown in Figs. 1 (a) and (b) respectively. A doublet is observed in the central part of the spectrum
recorded at RT. When the temperature decreases below RT, the sextet is more pronounced. This doublet is
attributed to superparamagnetism.
Figure 1 (c) shows the Mössbauer spectra recorded at RT and 4.2 K for the HT sample. Figure 1 (d) shows
the Mössbauer spectra recorded at RT and liquid He temperature for the sample ET4. Both HT and ET4
samples exhibited similar spectra which could be fitted with two components. The two sextets correspond tothe octahedral (A) and tetrahedral (B) Fe positions in the Co-Ni ferrite structure. From TEM studies, thediameters of the HT and ET4 samples were found to be equal to 30-40 nm. Superparamagnetic relaxation was
found to be absent at RT in both HT and ET samples.
In sufficiently small nanoparticles, the direction of magnetization can randomly invert as a result offluctuations in temperature. The typical time interval between two orientation inversions is given by the NèelArrhenius equation,
=

/

(1)

where K is the magnetic anisotropy energy density of the particle, V is the volume of the particle, kB is theBoltzmann constant and T is the temperature. τ0 is the attempt time with a value between 10−9 and 10−10 s.
The characteristic measurement time in milliseconds, τ1, corresponds to the Larmor precession period of
the 57Fe nucleus. For fine nanoparticles, the relaxation time, τ, is smaller than τ1, and the magnetic fluctuation
is so fast that the average internal magnetic hyperfine field at the 57Fe nuclei is equal to zero. In this case, a51

Fig. 1. 57Fe Mössbauer spectra of Co-Ni ferrite nanoparticles for the AP sample obtained at RT (a) and at
LT (b). 57Fe Mössbauer spectra of Co-Ni ferrite nanoparticles for the HT (c) and ET4 samples (d) obtainedat RT and LT.

doublet can be observed in the Mössbauer RT spectrum. As the temperature decreases, τ increases and becomesτ1. If this occurs, some 57Fe nuclei undergo rapid superparamagnetic relaxation and a doublet and sextet coexist
in the pattern [3]. As temperature further decreases the relaxation of nanoparticles becomes even slower andthe spectrum takes on the form of a sextet. The size of the nanoparticles increases significantly for the HT and
ET samples, making the temperature at which τ = τ1 much higher in these samples than RT. Thus it can beconcluded that the magnetic properties of superparamagnetic Co-Ni ferrites depend on their size and methodof synthesis. These results can provide a better understanding of the influence of different stages of synthesis
condition on the magnetic properties of the Co-Ni ferrites.
References[1] A.-D et al., Beni-Suef University Journal of Basic and Applied Sciences (2017).
[2] D. W. Collins et al., Mössbauer Effect Methodology, Springer, Boston, MA (1967) 103.
[3] Z. Surowiec et al., Nukleonika 62 (2017) 73.
[4] Q. Chen and Z. J. Zhang, Appl. Phys. Lett. 73 (1998) 3156.
52

4.14

Mössbauer spectroscopy study of spinel structured MnxFe2O4-δ particles
under external magnetic field

H. Latiff, M. Kishimoto, E. Kita, H. Yanagihara
Magnetic anisotropy of spinel ferrites can be enhanced via the symmetry reduction approach using lattice
distortion [1]. We proposed use of the Jahn-Teller (JT) effect of Cu2+ ions and reported on the coercivity
enhancement in tetragonal (Cu,Co)Fe2O4 particles [2]. In this study, we used Mn3+ as the source of JT effectto increase the magnetization. 57Fe Mössbauer experiments were performed for Mn ferrite particles toinvestigate the Fe3+ site distribution.
The Mn ferrite particles were synthesized by coprecipitation andhydrothermal methods. Aqueous solutions containing Mn2+ and Fe3+ with aratio of 1.3 : 2 were mixed with NaOH aqueous solution to form
precipitates, which were treated hydrothermally at 280°C. The particles asprepared (AP) in this way were subsequently heat-treated (HT), i.e.,annealed at 450°C in air to oxidize the Mn2+ to Mn3+. The X-ray diffraction(XRD) patterns are shown in Fig. 1. For the AP sample, all the peaks are
attributable to the cubic spinel phase. After heat-treated, splitting of thepeaks is observed, except for the (400) peak. Primarily, the peak splitting is
attributed to the JT effect of Mn3+ ions induced by the heat-treatment. In
CuFe2O4, such peak splitting indicates the tetragonal spinel phase transition
due to the JT effect. In this study, the (400) peak which accounts to the caxis showed no sign of splitting after the heat treatment. However, theFig. 1. XRD patterns of AP
and HT samples of Mn ferrite
particles.

intensity ratios of the other split peaks indicate a compressed c-axis type of distortion (c/a<1).
Figures 2 and 3 show zero-field (0T) and applied-field (5T) 57Fe Mössbauer spectra of the AP and HT
samples recorded at RT, respectively. The 0T spectra are fitted to a combination of two magnetic sextets.
The sub-spectra with higher and lower hyperfine field (Hhf) values are attributable to Fe3+(A) and Fe3+(B),respectively. The 0T literature values of the Hhf of the A and B sites are 48T and 43T, respectively [3]. The
0T spectra thus show considerably good agreement with the reported values within experimental errors. On
the other hand, the 5T spectra are fitted to a combination of two magnetic quadruplets which are clearly
separated. For the AP sample, the 5T spectrum composed of 3 sextets can be attributed to Fe (A↑), Fe (A↓),
and Fe (B↓), where ↑ and ↓ represent the minor (parallel to Hext) and the major (anti-parallel to Hext)
moments, respectively.
The fitting parameters used in Figs. 2 and 3 are listed in Table 1.The electric fields given in terms of Q.
S. values are effectively zero for the AP sample, indicating a highly symmetrical structure. In contrast, for
the HT sample there exists a non-zero value −0.189 mm/s for Fe(B) at 0T, indicating the presence of noncubic structure, which is consistent with the XRD pattern. The I. S. of all sub-spectra ranges from 0.22 to
0.37 mm/s, indicating that they originate from Fe3+, and not from Fe2+. At 5T, the area populations of the
Fe3+ ions distributed in the A and B sites are 50.7 and 49.3% for the AP sample; while 33 and 67% for the53

HT sample, respectively. The Fe cation can be distributed as [Fe]A(Mn,Fe)BO4 for the AP sample, and as[Fe0.67,Mn0.33]A(Mn0.66,Fe1.34)BO4 for the HT sample. If 33% of Mn in the A site are Mn3+ oxidized from Mn2+,
then there is a possible emergence of the JT effect by Mn3+ in the tetrahedral A site, causing a c/a<1 distortionof the system. Since there is no indication of the presence of Fe2+, this suggests that instead of Fe3+ reduction
to Fe2+, the charge is likely balanced by the presence of lattice vacancy defect. The cation distribution for
the HT sample is thus suggested as [Fe0.67,Mn0.33]A(Mn0.66,Fe1.0 0.34)BO4, where vacancy is represented by

-10

-5

H= 0T

H= 5T

exp.
fit
Fe(B)
Fe(A)
Fe(A)

0

5

exp.
fit
Fe(B)
Fe(A)

H= 0T

exp.
fit
Fe(B)
Fe(A)

Absorption (%)

Absorption (%)

the symbol .

Fe (A)Fe (B)

exp.
fit
Fe(B)
Fe(A)

H= 5T

10

Fe (B)Fe (A)-10-5Velocity (mm/s)

0

5

10

Velocity (mm/s)
57

Fig. 3. RT Fe Mössbauer spectra of heat-treated
Mn ferrite particles at Hext = 0T (top) and Hext =5T (bottom).

57

Fig. 2. RT Fe Mössbauer spectra of as-prepared
Mn ferrite particles at Hext = 0T (top) and Hext = 5T(bottom).

Table 1. Mössbauer fitting parameters.

References[1] T. Niizeki et al., Appl. Phys. Lett. 103 (2013) 162407.
[2] H. Latiff et al., IEEE Trans. Magn. 53 (2017) 9402304.
[3] G. A. Sawatzky et al., Phys. Letters 25A (1967) 147.

54

4.15

Magnetic properties of individual magnetite nanoparticles

H. Mamiya1
In recent years, the method for synthesizing magnetic nanoparticles has made remarkable progress.
However, the true magnetic characteristics of the nanoparticles such as magnetic anisotropy are yet to berevealed due to possible interactions between nanoparticles. As a consequence, the application- oriented
design of magnetic nanoparticles has become difficult. Thus in this study, we have prepared an idealinteraction-free magnetite nanoparticle system by coating magnetite particles with silica of enough shell
thicknesses to clarify the true magnetic anisotropy of individual magnetite nanoparticles.
First, magnetite particles with average diameters ranging from 8 to 23 nm were synthesized. Then,these magnetite particles were coated with silica shell of various thicknesses between 0 and 33 nm. Their
microscopic magnetic states were examined using 57Fe Mössbauer spectroscopy, while their macroscopic
magnetic properties were studied using SQUID magnetometry.
A typical 57Fe Mössbauer spectrum is shown in Fig. 1. The presence of six lines in the spectrum thus
indicates that its microscopic magnetic state is ferromagnetic. In the first-order reversal curve (FORC)
diagrams, we can find that interaction field disappears with coating. In other words, the magnetite
nanoparticles are magnetically isolated by the silica-shell, as expected. This fact can be confirmed by the
proportionality between the isothermal remanent magnetization and the DC demagnetization remanence.
Consequently, this advance enables us to study the true magnetic anisotropy of individual magnetite
nanoparticles in the next step.

Fig. 1. Typical 57Fe Mössbauer spectrum of the prepared magnetite nanoparticles.

1 National Institute for Materials Science

55

5.
BEAM IRRADIATION EFFECT

5.1

Construction of efficient radiation experiment system

A. Nagata, A. Yasuda, H. Watanabe, T. Kameda
The purpose of this research is to improve the accuracy and efficiency of radiation tests [1]. For thispurpose, a test support system was developed, and it was verified through radiation testing. Through thetests, the effectiveness of the test support system was confirmed and its points of improvement relative toprevious methods were identified. In addition, for the purpose of evaluating the space applicability of acommunication module using a commercial communication IC [2], radiation resistance testing was
conducted and the radiation resistances of a communication module and microcontroller, which areconsidered as a control microcontroller, were evaluated.
In this study, the test support system is made to detect SEEs (Single Event Effects), reset equipment,
and record automatically. The support system consists of current sensors, reset circuits, and processing
units (Fig. 1). The processing units are connected to the monitoring PC in the monitoring room; thus, thestatus can be monitored and the power to the test pieces is controlled with the monitoring PC. Figure 1
shows the schematic view of the support system. The following requirements for the support system weretabulated and validated in advance. (1) Ability to turn off power automatically when the consumption
current exceeds the threshold for the test piece.

(2) Ability to detect SEL (Single Event Latch up) andSEU (Single Event Upset) of a test piece automatically and record voltages and currents during SEE
occurrences along with the driving time taken from when power is supplied to the test piece to theoccurrence of the SEE. (3) Ability to log the test. (4) Support system transmission of the consumption
current, voltage, and occurrences of SEEs to the monitoring PC. (5) Ability to control the power to a test
piece using the monitoring PC in the monitoring room.
In this experiment, the support system needs to reset the test pieces automatically andinstantaneously in order to prevent them from breaking down owing to SELs. However, it is improbablefor an SEU to cause destruction, and power must be supplied to test pieces until the occurrence of an SEL
if an SEU is more likely to occur than an SEL. Therefore, an automatic reset for SEU detection by theprocessing unit was not adopted, but manual reset from the monitoring PC was used.
For the microcontroller, the test support system operated with automatic SEE detection andautomatic resets as expected, and it was confirmed that automatic detection of SEEs and automatic resets
for breakage prevention were effective. However, it was found that the support system could not detect theSELs of the communication module correctly using the conventional detection method because of thedifference in the consumption current during transmission and during standby. In the conventional method,
the threshold of the current value is set from approximately 1.5 to 2.0 times as much as the consumption
current during normal driving, and when the consumption current exceeds this threshold, an SEL is
detected. On the other hand, the consumption current of the communication module greatly differs
between radio wave transmission and standby modes, and it is difficult to set the threshold value based on
the current consumption value during normal driving.

57

Fig. 1. System block diagram.

In conclusion, a test support system that can detect SEEs automatically and can automatically resetthe equipment when SELs occur was studied and developed for the purpose of improving the accuracy andefficiency of radiation resistance tests. The test support system’s effectiveness and improvement points
were confirmed by using it in a radiation test experiment. Radiation resistance testing was conducted andthe radiation resistance of consumer communication modules being considered for space applications were
evaluated; specifically, microcontrollers considered as controllers for communication modules were tested.
It is found that the automatic SEE detection function and the automatic reset function are effective for
reducing the omission of SEE detection and reducing the risk of damage to test pieces. It is also found thatthe accuracy of test is expected to be improved by using the present test support system. On the other hand,the consumption current transition around an SEL of the communication module shows a different
tendency from that of the microcontroller. Therefore, the SEL detection method must still be improved.
The authors would like to thank K. Sasa and M. Sataka of UTTAC for technical assistance with theexperiments.
References[1] V. M. Placinta et al., Romanian Journal of Physics 62 (2017) 903.
[2] N. Ikeda et al., Transactions of the Institute of Electronics, Information and Communication Engineers,
Series B 88 (2005) 108.

58

5.2

Comparison of LET versus SEU cross section curves for irradiation withenergetic ions and with pulsed laser

K. Takeuchi, Y. Tsuchiya, K. Sakamoto, K. Yukumatsu, H. Shindo1, M. Sataka, K. Sasa
Commercial off-the-shelf (COTS) electronic parts are widely employed especially for small satellites
nowadays since the cost can be reduced efficiently. When selecting commercial parts for space application,
the most concerned issue is radiation effects: Single Event Upset (SEU), Single Event Latch-up (SEL),
Total Ionizing Dose (TID), and so on. Because COTS parts do not have enough radiation tolerance inmany cases, accurate estimation of the error rate is necessary for practical use. The cross section of COTS
parts for radiation effects noted above changes significantly in a narrow and low range of linear energy
transfer (LET). Therefore, various radiation ion sources are needed to determine the accurate device crosssection and the error rate.
A new vacuum chamber for the irradiation test, as shown in Fig. 1, was built in the beam line of theUTTAC 6MV tandem accelerator which generates energetic ions with various LET values by changing theacceleration voltage. This report describes evaluation results of a 9M bit SRAM device using the facility.
In addition, we study the pulsed laser technique to estimate the cross section curve [1], which could be analternative tool for the irradiation test procedure.
The vacuum chamber at UTTAC is equipped with various types of feedthroughs and a three-axis
goniometer stage to set electronic parts at a desired position precisely. Besides, de-capped photo-diodesensors were placed next to the device to count the ion beam flux. Figure 2 shows the LET versus SEU
cross section curve of the SRAM device. The plots in blue and red were obtained at UTTAC and the
Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), respectively. The data obtainedat UTTAC is compatible as a quantitative evaluation with other measurements because they are in good
agreement between the facilities. Li ion was selected as a radiation source to determine the accurate crosssection around the LET range of 0.7 to 1.4 MeV/(mg/cm2) where the cross section changes significantly.
The device error rate under a certain radiation environment can be calculated from the acquired
characteristics of the curve.
We study another approach to determine the cross section curve using the pulsed laser technique tosimplify the irradiation test procedure for COTS parts. The backside of the SRAM device was drilled sothat the pulsed laser beam could reach the sensitive area of the transistors. Figure 3 shows a comparison
result between the heavy ion at UTTAC and the pulsed laser. The LET value of the pulsed laser
experiment is calculated as a function of the laser intensity and the physical parameters associating withthe test conditions [1]. The saturated cross section value is consistent with the result by the heavy ions.
However, when looking at the region of the small cross section, the calculated LET values are not matchedwith the heavy ion results. It would be caused by the difference between the laser spot size and thetransistor sensitivity area and/or the laser intensity profile. Further investigation of the disagreement will
be required.

59

Fig. 2. SEU cross section vs. LET, obtained fromthe experiments at UTTAC and TIARA.

Fig. 1. The vacuum chamber at UTTAC for irradiation
test of electronic parts.

Fig. 3. SEU cross sections determined from the experiments at
UTTAC and the pulsed laser technique.

Reference[1] S. P. Buchner et al., IEEE Transactions on Nuclear Science 60 (2013) 1852.

1 Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba-city, Ibaraki, JAPAN60

6.
LIST OF PUBLICATIONS AND PRESENTATIONS

6.1

Journals

ACCELERATOR AND RELATED FACILITIES
1.

A. Yamazaki, K. Sasa, S. Ishii, M. Kurosawa, S. Tomita, Y. Shiina, S. Shiki, G. Fujii, M. Ukibe, M.
Ohkubo, A. Uedono, E. Kita, Development of a microbeam PIXE system for additive light elements
in structural materials, Nuclear Instruments and Methods in Physics Research B, 404 92-95 (2017).

NUCLEAR AND ATOMIC PHYSICS
1.

T. Tanaka, Y. Narikiyo, K. Morita, K. Fujita, D. Kaji, K. Morimoto, S. Yamaki, Y. Wakabayashi, K.
Tanaka, M. Takeyama, A. Yoneda, H. Haba, Y. Komori, S. Yanou, B. J.-P. Gall, Z. Asfari, H. Faure,
H. Hasebe, M. Huang, J. Kanaya, M. Murakami, A. Yoshida, T. Yamaguchi, F. Tokanai, T. Yoshida,
S. Yamamoto, Y. Yamano, K. Watanabe, S. Ishizawa, M. Asai, R. Aono, S. Goto, K. Katori, and K.
Hagino, Determination of fusion barrier distributions from quasielastic scattering cross sections
towards superheavy nuclei synthesis, J. Phys. Soc. Jpn. 87, 014201/1-9 (2018).

2.

Q. Zeng, M. Wang, X. H. Zhou, Y. H. Zhang, X. L. Tu, X. C. Chen, X. Xu, Yu. A. Litvinov, H. S. Xu,
K. Blaum, R. J. Chen, C. Y. Fu, Z. Ge, W. J. Huang, H. F. Li, J. H. Liu, B. Mei, P. Shuai, M. Si, B. H.
Sun, M. Z. Sun, Q. Wang, G. Q. Xiao, Y. M. Xing, T. Yamaguchi, X. L. Yan, J. C. Yang, Y. J. Yuan,
Y. D. Zang, P. Zhang, W. Zhang, and X. Zhou, Half-life measurement of short-lived 94mRu44+ usingisochronous mass spectrometry, Physical Review C 96, 031303(R)/1-5 (2017).

3.

J. C. Zamora, T. Aumann, S. Bagchi, S. Boenig, M. Csatlos, I. Dillmann, C. Dimopoulou, P. Egelhof,
V. Eremin, T. Furuno, H. Geissel, R. Gernhaeuser, M. N. Harakeh, A.-L. Hartig, S. Ilieva, N. KalantarNayestanaki, O. Kiselev, H. Kollmus, C. Kozhuharov, A. Krasznahorkay, Th. Kroell, M. Kuilman, S.
Litvinov, Yu. A. Litvinov, M. Mahjour-Shafiei, M. Mutterer, D. Nagae, M. A. Najafi, C. Nociforo, F.
Nolden, U. Popp, C. Rigollet, S. Roy, C. Scheidenberger, M. von Schmid, M. Steck, B. Streicher, L.
Stuhl, M. Thuerauf, T. Uesaka, H. Weick, J. S. Winfield, D. Winters, P. J. Woods, T. Yamaguchi, K.
Yue, and J. Zenihiro, Nuclear-matter radius studies from 58Ni (α, α) experiments at the GSI
Experimental Storage Ring with the EXL facility, Physical Review C 96, 034617/1-6 (2017).

4.

E. Miyata, M. Takechi, T. Ohtsubo, M. Fukuda, D. Nishimura, K. Abe, K. Aoki, A. Ikeda, T.
Izumikawa, H. Oikawa, K. Ohnishi, S. Ohmika, I. Kato, Y. Kanke, N. Kanda, R. Kanbe, H. Kikuchi,
A. Kitagawa, S. Sato, H. Shimamura, J. Shimaya, S. Suzuki, T. Suzuki, R. Takagaki, H. Takahashi, Y.
Takei, Y. Takeuchi, T. Takenouchi, N. Tadano, M. Tanaka, Y. Tanaka, K. Chikaato, H. Du, J. Nagumo,
K. Nishizuka, T. Nishimura, S. Fukuda, M. Machida, A. Mizukami, M. Mihara, J. Muraoka, S. Yagi,
S. Yamaoka, T. Yamaguchi, K. Yokoyama, Development of high resolution TOF detector for RI beams
using Cherenkov radiation, Acta Phys. Pol. B 48, 409-412 (2017).

61

5.

H. Du, M. Fukuda, D. Nishimura, M. Takechi, T. Suzuki, Y. Tanaka, I. Kato, M. Tanaka, K. Abe, T.
Izumikawa, H. Oikawa, T. Ohtsubo, J. Ohno, Y. Kanke, H. Kikuchi, A. Kitagawa, S. Sato, U. Sayama,
J. Shimaya, S. Suzuki, Y. Takeuchi, T. Takemoto, N. Tadano, R. Tamura, J. Nagumo, K. Nishizuka,
S. Fukuda, K. Hori, S. Matsunaga, A. Mizukami, M. Mihara, E. Miyata, D. Murooka, S. Yamaoka, T.
Yamaguchi, Nuclear structure of 15,16C via reaction cross-section measurements, Acta Phys. Pol. B 48,
473-479 (2017).

6.

M. Tanaka, M. Fukuda, D. Nishimura, M. Takechi, S. Suzuki, H. Du, Y. Tanaka, K. Aoki, S. Fukuda,
A. Honma, T. Izumikawa, Y. Kamisho, N. Kanda, I. Kato, Y. Kanke, A. Kitagawa, J. Kohno, M.
Machida, K. Matsuta, M. Mihara, E. Miyata, Y. Morita, J. Muraoka, D. Murooka, T. Nagai, M.
Nagashima, K. Ohnishi, J. Ohno, T. Ohtsubo, H. Oikawa, S. Sato, H. Shimamura, T. Sugihara, T.
Suzuki, N. Tadano, R. Takagaki, Y. Takei, A. Takenouchi, S. Yagi, T. Yamaguchi, S. Yamaki, S.
Yamaoka, Reaction cross sections for 13-15B and one-neutron halo in 14B, Acta Phys. Pol. B 48, 461466 (2017).

7.

A. Homma, M. Takechi, T. Ohtsubo, D. Nishimura, M. Fukuda, T. Suzuki, T. Yamaguchi, T. Kuboki,
A. Ozawa , S. Suzuki , H. Ooishi , T. Moriguchi , T. Sumikawa, H. Geissel, N. Aoi, R.-J. Chen, D.-Q.
Fang, N. Fukuda, S. Fukuoka, H. Furuki, N. Inaba, N. Ishibashi, T. Ito, T. Izumikawa, D. Kameda, T.
Kubo, M. Lantz, C. S. Lee, Y.-G. Ma, M. Mihara, S. Momota, D. Nagae, R. Nishikiori, T. Niwa, T.
Ohnishi, K. Okumura, T. Ogura, M. Nagashima, H. Sakurai, K. Sato, Y. Shimbara, H. Suzuki, H.
Takeda, S. Takeuchi, K. Tanaka, H. Uenishi, M. Winkler, Y. Yanagisawa, Measurements of interaction
cross sections for 19-27F isotopes, JPS Conf. Proc. 14, 021010/1-3 (2017).

8.

K. Nishizuka, M. Takechi, T. Ohtsubo, D. Nishimura, M. Fukuda, K. Aoki, K. Abe, A. Ikeda, T.
Izumikawa, H. Oikawa, K. Ohnishi, J. Ohno, S. Ohmika, I. Kato, Y. Kanke, S. Kanbe, N. Kanda, H.
Kikuchi, A. Kitagawa, S. Sato, U. Sayama, J. Shimaya, T. Sugihara, S. Suzuki, T. Suzuki, H. Takahashi,
Y. Taguchi, Y. Takei, Y. Takeuchi, A. Takenouchi, T. Takemoto, N. Tadano, M. Tanaka, Y. Tanaka,
K. Chikaato, H. Du, T. Nagai, J. Nagumo, S. Fukuda, K. Hori, A. Honma, M. Machida, S. Matsunaga,
A. Mizukami, M. Mihara, E. Miyata, D. Murooka, S. Yagi, S. Yamaoka, T. Yamaguchi, K Yokoyama,
Measurements of reaction cross sections for 9-11C, JPS Conf. Proc. 14, 021015/1-3 (2017).

9.

K. Sawahata, A. Ozawa, Y. Saito, Y. Abe, Y. Ichikawa, N. Inaba, Y. Ishibashi, A. Kitagawa, S.
Matsunaga, T. Moriguchi, D. Nagae, S. Okada, S. Sato, S. Suzuki, T. Suzuki, Y. Takeuchi, T.
Yamaguchi, J. Zenihiro, Investigations of charge-changing processes for light proton-rich nuclei oncarbon and solid-hydrogen targets, Nuclear Physics A 961, 142-153 (2017).

10.

D. Kaji, K. Morita, K. Morimoto, H. Haba, M. Asai, K. Fujita, Z. Gan, H. Geissel, H. Hasebe, S.
Hofmann, M. Huang, Y. Komori, L. Ma, J. Maurer, M. Murakami, M. Takeyama, F. Tokanai, T.
Tanaka, Y. Wakabayashi, T. Yamaguchi, S. Yamaki, and A. Yoshida, Study of the Reaction 48Ca +248

Cm → 296Lv* at RIKEN-GARIS, J. Phys. Soc. Jpn 86, 034201/1-7 (2017).

6211. P. Zhang, X. Xu, P. Shuai, R.J. Chen, X.L. Yan, Y.H. Zhang, M. Wang, Yu.A. Litvinov, K. Blaum, H.S.
Xu, T. Bao, X.C. Chen, H. Chen, C.Y. Fu, J.J. He, S. Kubono, Y.H. Lam, D.W. Liu, R.S. Mao, X.W.
Ma, M.Z. Sun, X.L. Tu, Y.M. Xing, J.C. Yang, Y.J. Yuan, Q. Zeng, X. Zhou, X.H. Zhou, W.L. Zhan, S.
Litvinov, G. Audi, T. Uesaka, Y. Yamaguchi, T. Yamaguchi, A. Ozawa, B.H. Sun, Y. Sun, F.R. Xu,
High-precision QEC values of super allowed 0+ -> 0+ β-emitters 46Cr, 50Fe, and 54Ni, Phys. Lett. B 767,
20-24 (2017).
12. X. L. Tu, A. Kelic-Heil, Yu. A. Litvinov, Zs. Podolyak, Y. H. Zhang, W. J. Huang, H. S. Xu, K. Blaum,
F. Bosch, R. J. Chen, X. C. Chen, C. Y. Fu, B. S. Gao, Z. Ge, Z. G. Hu, D. W. Liu, S. A. Litvinov, X.
W. Ma, R. S. Mao, B. Mei, P. Shuai, B. H. Sun, Y. Sun, Z. Y. Sun, P. M. Walker, M. Wang, N. Winckler,
J. W. Xia, G. Q. Xiao, Y. M. Xing, X. Xu, T. Yamaguchi, X. L. Yan, J. C. Yang, Y. J. Yuan, Q. Zeng, W.
Zhang, H. W. Zhao, T. C. Zhao, and X. H. Zhou, Application of isochronous mass spectrometry for the
study of angular momentum population in projectile fragmentation reactions, Physical Review C 95,
014610/1-6 (2017).
13. Y. Hirayama, Y.X. Watanabe, M. Mukai, M. Oyaizu, M. Ahmed, H. Ishiyama, S.C. Jeong, Y. Kakiguchi,
S. Kimura, J.Y. Moon, J.H. Park, P. Schury, M. Wada, H. Miyatake, Doughnut-shaped gas cell for KEK
Isotope Separation System, Nuclear Instruments and Methods in Physics Research B 412, 11 (2017).
14. Y. Hirayama, M. Mukai, Y. X. Watanabe, M. Ahmed, S. C. Jeong, H. S. Jung, Y. Kakiguchi, S. Kanaya,
S. Kimura, J. Y. Moon, T. Nakatsukasa, M. Oyaizu, J. H. Park, P. Schury, A. Taniguchi, M. Wada, K.
Washiyama, H. Watanabe, and H. Miyatake, In-gas-cell laser spectroscopy of the magnetic dipole
moment of the N ≈126 isotope 199Pt, Physical Review C 96 (2017) 014307.
15. Y. Hirayama, M. Mukai, Y. Watanabe, M. Oyaizu, M. Ahmed, Y. Kakiguchi, S. Kimura, Ionization
cross section, pressure shift and isotope shift measurements of osmium H. Miyatake, P. Schury, M.
Wada and Sun-Chan Jeong, Ionization cross section, pressure shift and isotope shift measurements ofosmium, J. Phys. B: At. Mol. Opt. Phys. 50 (2017) 215203.
16. M. Mukai, Y. Hirayama, Y.X. Watanabe, P. Schury, H.S. Jung, M. Ahmed, H. Haba, H. Ishiyama, S.C.
Jeong, Y. Kakiguchi, S. Kimura, J.Y. Moon, M. Oyaizu, A. Ozawa, J.H. Park, H. Ueno, M. Wada, and
H. Miyatake, High-efficiency and low-background multi-segmented proportional gas counter for βdecay spectroscopy, Nuclear Instruments and Methods in Physics Research A 884,1 (2018).

63

ACCELERATOR MASS SPECTROMETRY
1.

Yukihiko Satou, Keisuke Sueki, Kimikazu Sasa, Hideki Yoshikawa, Shigeo Nakama, Haruka
Minowa, Yoshinari Abe, Izumi Nakai, Takahiro Ono, Kouji Adachi and Yasuhito Igarashi,
Analysis of two forms of radioactive particles emitted during the early stages of the Fukushima
Dai-ichi Nuclear Power Station accident, Geochemical Journal, Vol. 52, 137-143, 2018.
doi:10.2343/geochemj.2.0514

2.

Masumi Matsumura, Kimikazu Sasa, Tetsuya Matsunaka, Keisuke Sueki, Tsutomu Takahashi
and Hiroyuki Matsuzaki, Temporal variation of iodine-129 in rainwater at Tsukuba before andafter the Fukushima Daiichi Nuclear Power Plant accident, Geochemical Journal, Vol. 52, 155162, 2018. doi:10.2343/geochemj.2.0504

3.

Seiji Hosoya, Kimikazu Sasa, Tetsuya Matsunaka, Tsutomu Takahashi, Masumi Matsumura,
Hiroshi Matsumura, Mark Sundquist, Mark Stodola, Keisuke Sueki, Optimization of a ΔE - E
detector for 41Ca AMS, Nuclear Instruments and Methods in Physics Research B, 406, 268271, 2017. DOI: 10.1016/j.nimb.2017.03.161

BEAM AND ISOTOPE APPLICATIONS
1.

A. Uedono, S. Takashima, M. Edo, K. Ueno, H. Matsuyama, W. Egger, T. Koschine, C. Hugenschmidt,
M. Dickmann, K. Kojima, S. F. Chichibu, and S. Ishibashi, Carrier trapping by vacancy-type defects
in Mg-implanted GaN studied using monoenergetic positron beams, Phys. Stat. Sol. B 2017,
1700521(1-9). [DOI: 10.1002/pssb.201700521]

2.

L. V. Devi, S. Sellaiyan, T. Selvalakshmi, H.J. Zhang, A. Uedono, K. Sivaji, S. Sankar, Synthesis, defectcharacterization and photocatalytic degradation efficiency of Tb doped CuO nanoparticles, Adv.
Powder Tech. 28, (2017) 3026-3038. [DOI: 10.1016/j.apt.2017.09.013]

3.

S. R. Aid, T. Uneme, N. Wakabayashi, K. Yamazaki, A. Uedono, and S. Matsumoto, Carrier activationin Mg implanted GaN by short wavelength Nd:YAG laser thermal annealing, Phys. Stat. Sol. A 214,
1700225(1-5) (2017). [DOI: 10.1002/pssa.201700225]

4.

A. Uedono, T. Tanaka, N. Ito, K. Nakahara, W. Egger, C. Hugenschmidt, S. Ishibashi, and M. Sumiya,
Electron capture by vacancy-type defects in carbon-doped GaN studied using monoenergetic positron
beams, Thin Solid Films 639, (2017) 78-83. [DOI: 10.1016/j.tsf.2017.08.021]

5.

A. Uedono, M. Imanishi, M. Imade, M. Yoshimura, S. Ishibashi, M. Sumiya, and Y. Mori, Vacancytype defects in bulk GaN grown by the Na-flux method probed using positron annihilation, J. Cryst.
Growth 475, (2017) 261-265. [DOI: 10.1016/j.jcrysgro.2017.06.027]

64

6.

L. V. Devi, T. Selvalakshmi, S. Sellaiyan, A. Uedono, K. Sivaji, S. Sankar, Effect of La doping on thelattice defects and photoluminescence properties of CuO, J. Alloys & Comp. 709, (2017) 496-504.
[DOI: 10.1016/j.jallcom.2017.03.148]

7.

H. J. Zhang, S. Sellaiyan, T. Kakizaki, A. Uedono, Y. Taniguchi, K. Hayashi, Effect of Free-Volume
Holes on Dynamic Mechanical Properties of Epoxy Resins for Carbon-Fiber-Reinforced Polymers,
Macromolecules 50, (2017) 3933-3942. [DOI: 10.1021/acs.macromol.7b00472]

8.

Y. Mizushima, Y. Kim, T. Nakamura, A. Uedono, and T. Ohba, Behavior of copper contamination on
backside damage for ultra-thin silicon three dimensional stacking structure, Microelectronic
Engineering 167, 23 (2017).

9.

F. Inoue, A. Jourdain, L. Peng, A. Phommahaxay, J. De Vos, K. J. Rebibis, A. Miller, E. Sleeckx, E.
Beyne, and A. Uedono, Influence of Si wafer thinning processes on (sub)surface defects, Applied
Surface Science 404, 82 (2017).

10. S. F. Chichibu, K. Kojima, A. Uedono, and Y. Sato, Defect-Resistant Radiative Performance of m-Plane
Immiscible Al1-xInxN Epitaxial Nanostructures for Deep-Ultraviolet and Visible Polarized Light
Emitters, Advanced Materials 29, 1603644 (2017). [DOI: 10.1002/adma.201603644]
11. S. Ishibashi, H. Kino, A. Uedono, T. Miyake, and K. Terakura, Prediction of positron-annihilation
parameters for vacancy-type defects in ternary alloy semiconductors by data-scientific approach, J.
Phys.: Conf. Ser. 791, 012023(1-5) (2017). [DOI: 1088/1742-6596/791/1/012023]
12. K. Kojima, S. Takashima, M. Edo, K. Ueno, M. Shimizu, T. Takahashi, S. Ishibashi, A. Uedono, and S.
F. Chichibu, Nitrogen vacancies as a common element of the green luminescence and nonradiative
recombination centers in Mg-implanted GaN layers formed on a GaN substrate, APEX 10, 061002(2017). [https://doi.org/10.7567/APEX.10.061002]
13. M. Saito, T. Tanabe, M. Lintuluoto, E. B. Starikov, K. Noda, T. Majima, S. Tomita and K. Takahashi,
Photodissociation of orange I monoanion studied using an electrostatic storage ring, Journal of Physics:
Conference Series 875, 032035 (2017).
14. V. Motaneeyachart, Y. Hirose, A. Suzuki, S. Nakao, I. Harayama, D. Sekiba, T. Hasegawa, Epitaxial
Growth of Baddeleyite NbON Thin Films on Yttria-Stabilized Zirconia by Pulsed Laser Deposition,
Chem. Lett. 47, 65 (2018).
15. T. Katayama, A. Chikamatsu, Y. Hirose, M. Minohara, H. Kumigashira, I. Harayama, D. Sekiba, T.
Hasegawa, Ferromagnetism with strong magnetocrystalline anisotropy in A-site ordered perovskite

65

YBaCo2O6 epitaxial thin film prepared via wet-chemical topotactic oxidation, J. Mater. Chem. C 6,3445 (2018).
16. I. Harayama, D. Sekiba, Q. Zhao, A. Vantomme, W. Vandervorst, J. Meersschaut, Calibration of PIXE
yields using Cu as a reference, Nuclear Instruments and Methods in Physics Research Section B 406,
115-118 (2017).
17. D. Sekiba, K. Chito, I. Harayama, Y. Watahiki, S. Ishii, K. Ozeki, Installation of high-resolution ERDAin UTTAC at the University of Tukuba: Determination of the energy resolution and the detection limit
for hydrogen, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions
with Materials and Atoms, Volume 401, 29-32 (2017).
18. K. Kawahara, A. Chikamatsu, T. Katayama, T. Onozuka, D. Ogawa, K. Morikawa, E. Ikenaga, Y.
Hirose, I. Harayama, D. Sekiba, T. Fukumura, T. Hasegawa, Topotactic fluorination of perovskite
strontium ruthenate thin films using polyvinylidene fluoride, CrystEngComm, 19, 313-317 (2017).
19. T. Onozuka, A. Chikamatsu, T. Katayama, Y. Hirose, I. Harayama, D. Sekiba, E. Ikenaga, M. Minohara,
H. Kumigashira, T. Hasegawa, Reversible resistance modulation induced by fluorine substitution inperovskitenickelate NdNiO2 thin films, ACS Appl. Mater. Interfaces, 9, 10882-10887 (2017).
20. N. Nagakura, K. Fujii, I. Harayama, Y. Kato, D. Sekiba, Y. Watahiki, S. Yamashita, Experimental
verification of a gain reduction model for the space charge effect in a wire chamber, Prog. Theor. Exp.
Phys. 013C01 (2018).
21. M. Saito, T. Tanabe, M. Lintuluoto, E. B. Starikov, K. Noda, T. Majima, S. Tomita and K. Takahashi,
Photodissociation of orange I monoanion studied using an electrostatic storage ring, Journal of Physics,
Conference Series 875, 032035 (2017).
22. E Kita, H Yanagihara, M Kishimoto, K Ota, R Miyamoto, T Oda, N. Ohkohchi,
Dynamic magnetization properties of platelet ferromagnetic nanoparticles and their heat generation
injected in tumors of mice, IEEE Trans. Magn., 53 (11), 5100905 (2017).
23. H Latiff, M Kishimoto, S Sharmin, E Kita, H Yanagihara, T Nakagawa, Enhanced anisotropy intetragonalized (Cu,Co)Fe2O4 particles via the Jahn-Teller effect of Cu2+ ions, IEEE Trans. Magn., 53(11), 9402304 (2017).
24. Eiji Kita, Kenichi Shibata, Yuji Sasaki, Mikio Kishimoto, and Hideto Yanagihara, Magnetic
anisotropy in spherical Fe16N2 core–shell nanoparticles determined by torque measurements
AIP Advances 7 (2017) 056212.

66

6.2
1.

Reviews and books
黒澤 正紀、 鉱物の微細組織・化学組成に基づいた土器の焼成温度推定, 現代文明の基層としての古代西アジア文明ニュースレター、vol. 9, 55-60, 2017.

2.

笹 公和、イオンビーム多目的利用研究のための筑波大学 6 MV タンデム型静電加速器、日本加速器学会誌「加速器」、14 巻 1 号 5-14（2017）.

3.

6.3
1.

SEKIBA Daiichiro, Compendium of Surface and Interface Analysis, Chapter 12, Elastic
Recoil Detection Analysis, Chapter 87, Rutherford Backscattering Spectrometry, Springer,
2018.

Poster or oral presentations at academic meetings
上殿明良、石橋章司、角谷正友、“陽電子消滅による窒化物半導体中 0 次元特異構造（点欠陥）のキャリア捕獲の評価”、 第 65 回応用物理学会春季学術講演会、早稲田大学、東京、
2018 年 3 月 19 日．(招待講演)

2.

A. Uedono, M. Sumiya, and S. Ishibashi, “Carrier trapping by vacancy-type defects in group-III
nitrides studied by means of positron annihilation”, Third DAE-BRNS Trombay Positron Meeting,
Bhabha Atomic Research Centre, Mumbai, India, 23th March 2018 (Invited).

3.

S. F. Chichibu, K. Kojima, A. Uedono, and Y. Sato, “Vacuum-fluorescent-display devices emitting
polarized deep-ultraviolet and visible lights using m-plane Al1-xInxN epitaxial nanostructures”, 11th Int.
Sym. Semiconductor Light Emitting Devices, Banff, Alberta, Canada, 10th October 2017 (Invited).

4.

A. Uedono, Study of point defects in nitrides and oxides by means of positron annihilation, 5th Int.
Conf. Light-Emitting Devices and Their Industrial Applications, Pacifico Yokohama, Yokohama,Japan, 21st April 2017 (Invited).

5.

A. Ozawa, “Rare-RI Ring in RIKEN RI Beam Factory” China-Japan collaboration workshop

on“Nuclear mass and life for unravelling mysteries of r-process” 2017, 6/26-28, University of Tsukuba,
Tsukuba, Japan (Invited).
6.

小沢 顕、不安定核の質量測定, 第 61 回放射化学討論会
筑波大学

7.

核化学分科会、2017, 9/7,

(Invited).

A. Ozawa, “Past and future of Rare-RI Ring”, The 10th International Conference on Nuclear Physics
at Storage Rings (STORI’17), 2017, 11/13-18, Kanazawa theater, Kanazawa, Japan (Invited).

67

8.

T. Yamaguchi, “Storage-ring mass spectrometry of exotic nuclei”, International symposium on RI
beam physics in the 21st century: 10th anniversary of RIBF, RIKEN, Wako, Japan, 4-5 Dec., 2017
(Invited).

9.

T. Yamaguchi, “ILIMA project: isomeric beams, lifetimes and masses at the FAIR storage rings”, 10th
International Conference on Nuclear Physics at Storage Rings, Kanazawa, Japan, 13-18 Nov., 2017
(Invited).

10. T. Yamaguchi, “ILIMA status report”, NUSTAR week 2017, Jozef Stefan Institute, Ljubljana,
Slovenia, 25-29 Sep., 2017 (Invited).
11. Kimikazu Sasa, Tsutomu Takahashi, Seiji Hosoya, Kenta Takano, Yuta Ochiai, Maki Honda, Yuki
Ohta, Aya Sakaguchi, Tetsuya Matsunaka, Hongtao Shen and Keisuke Sueki, Progress in Multinuclide AMS for the 6 MV AMS System at the University of Tsukuba, The 7th East Asia Accelerator
Mass Spectrometry Symposium (EA-AMS 7), Guangxi Normal University, Guilin, China, November
20th to 25th 2017 (Invited).
12. Tetsuya Matsunaka, Kimikazu Sasa, Seiji Hosoya, HongTao Shen, Tsutomu Takahashi, Masumi
Matsumura, Keisuke Sueki, Yukihiko Satou, Rapid C-14 measurement system at the University ofTsukuba and application for nuclear safety, The 7th East Asia Accelerator Mass Spectrometry
Symposium (EA-AMS 7), Guangxi Normal University, Guilin, China, November 20th to 25th 2017
(Invited).
13. E. Kita, H. Yanagihara, M. Kishimoto, R. Miyamoto, T. Oda and N. Ohkohchi
Dynamic magnetization properties and heat generation of platelet ferromagnetic nanoparticles injected
in tumors of mice, InterMAG Europe 2017, Dublin, Ireland 24th - 28th April 2017 (Invited).
14. 笹

公和、「加速器質量分析法（AMS）による極微量放射性核種の高感度分析手法の開発」、京都大学原子炉実験所専門研究会「放射化分析及び中性子を用いた地球化学的研究 -1-」、
京都大学原子炉実験所（大阪府熊取市）、2018 年 1 月 10 日（水）. (招待講演)
15. 笹

公和、「タンデム・静電加速器を用いた先端研究の現状と将来展望‐第 30 回「タンデム加速器及びその周辺技術の研究会」を記念して‐」、第 30 回「タンデム加速器及びその周辺技術の研究会」セラトピア土岐、岐阜県土岐市、日本原子力研究開発機構東濃地科学センター、2017 年 7 月 6- 7 日.（招待講演）

6816. 関場大一郎、イオンビーム分析における検出器開発、平成 29 年度

電気学会低レベル放射線（能）に関する技術調査専門委員会ミニシンポジウム「放射線計測半導体検出器の先端開発と応用」、東京大学

弥生講堂アネックス

セイホクギャラリー、2017 年 11 月 1 日.（招待講演）
17. 関場大一郎、イオンビーム分析：水素を含む軽元素絶対深さプロファイル決定と構造解析、
日本表面科学会

第 2 回関東支部講演大会、東京大学

山上会館、2017 年 4 月 8 日.（招待講演）
18. 笹 公和，細谷青児，本多真紀，高橋 努，佐藤志彦，高野健太，落合悠太，末木啓介，加速器質量分析法によるストロンチウム 90 の迅速定量法の開発，日本原子力学会「2018 年春の年会」，大阪大学吹田キャンパス（大阪市），2018 年 3 月 26 日~28 日.
19. S. Ishibashi and A. Uedono, Theoretical Calculation of Positron Annihilation Parameters for defects
in UV materials (AlN, ZnO, Ga2O3), Int. Workshop on UV Materials and Devices, Fukuoka, Japan,
14th November 2017.
20. S. Iwashita, T. Moriya, T. Kikuchi, N. Noro, T. Hasegawa, and A. Uedono, Correlation between ion
energies in CCRF discharges and film characteristics of titanium oxides fabricated via plasma
enhanced atomic layer deposition, AVS 65th Int. Sym. & Exhibition, Long Beach Convention CenterLong Beach CA, USA, 21th October 2017.
21. A. Uedono, Behaviors of free volumes during curing processes of epoxy resins for CFRP studied bypositron annihilation, Joint Sym. 3rd Innovative Measurement and Analysis for Structural Materials
and TIA-Fraunhofer workshop, AIST, Tsukuba, Japan, 4th October 2017.
22. S. Ishibashi and A. Uedono, Theoretical Calculation of Positron Annihilation Parameters in Group-III
nitrides, 29th Int. Conf. Defects in Semiconductors, Matsue, Japan, 1st August 2017.
23. S. F. Chichibu, K. Kojima, S. Takashima, M. Edo, K. Ueno, M. Shimizu, T. Takahashi, S. Ishibashi,and A. Uedono, Role of point defects on the luminescent properties of epitaxial and ion-implanted Mgdoped GaN fabricated on a GaN substrate, 12th Int. Conf. Nitride Semiconductors, Strasbourg
Convention Center, Strasbourg, France, 24th July 2017.
24. 角谷正友、福田清貴、上田茂典、浅井祐哉、Cho Yujin、関口隆史、上殿明良、尾沼猛儀、Sang
Liwen、本田徹、III-V 族窒化物の価電子帯構造およびギャップ内準位の評価、第 65 回応用物理学会春季学術講演会、早稲田大学、東京、2018 年 3 月 20 日.

69

25. 嶋紘平、井口紘子、成田哲生、片岡恵太、上殿明良、小島一信、秩父重英、Mg イオン注入
N 極性面 GaN の時間分解フォトルミネッセンス評価、第 65 回応用物理学会春季学術講演会、早稲田大学、東京、2018 年 3 月 19 日.
26. 高島信也、田中亮、上野勝典、松山秀昭、江戸雅晴、小島一信、秩父重英、上殿明良、中川
清和、Mg イオン注入 GaN MOSFET のチャネル特性向上、第 65 回応用物理学会春季学術講
演会、早稲田大学、東京、2018 年 3 月 19 日.
27. 松木伸行、松井卓矢、満汐孝治、オローク ブライアン、大島永康、上殿明良、a-Si:H/c-Si ヘ
テロ界面近傍ボイド構造の高速評価－ボイドサイズと光学パラメータの相関普遍性に関する考察－、第 65 回応用物理学会春季学術講演会、早稲田大学、東京、2018 年 3 月 18 日.
28. 秩父重英、小島一信、嶋紘平、高島信也、江戸雅晴、上野勝典、石橋章司、上殿明良、Ga 基
板上 Mg 添加 GaN の時間分解フォトルミネッセンス評価、第 78 回応用物理学会秋季学術講
演会、福岡国際会議場、福岡、2017 年 9 月 7 日.
29. 松木伸行、オローク ブライアン、大島永康、上殿明良、a-Si:H/c-Si ヘテロ界面近傍ボイド構造の高速評価－ボイドサイズ・水素結合・Si 結合角ゆらぎの相互相関－、第 78 回応用物理学会秋季学術講演会、福岡国際会議場、福岡、2017 年 9 月 6 日.
30. 大 和良 広 、 EPICS と CSS を 用 い た 偏 極 イ オ ン 源 制 御 シ ス テ ム の 開 発

Development of the polarized ion source control system using EPICS and CSS、日本加速器学会第14 回年会、 平成 29 (2017)年 8 月.
31. 大和 良広,

偏極イオン源の現状 （震災復旧３）、第 30 回タンデム加速器及びその周辺技術の研究会、日本原子力研究開発機構

東濃地科学センター、平成 29(2017)年 7 月.

32. T. Moriguchi et al., Lamb-shift Polarized Ion Source at UTTAC, The 2017 International Workshop on
Polarized Sources, Targets & Polarimetry(PSTP2017), KAIST Munji Campus, Dajeon, Republic ofKorea, Oct 16-20, 2017.
33. 森口哲朗、筑波大学タンデム加速器施設 UTTAC の現状（2016 年度）、第 30 回タンデム加速器及びその周辺技術の研究会、日本原子力研究開発機構

東濃地科学センター（岐阜県）、

2017/07/06-07.
34. 森口哲朗、偏極陽子ビームを用いた陽子吸収反応による不安定核の核偏極、日本物理学会
2017 秋季大会、宇都宮大学峰キャンパス、2017/09/12-15.

7035. 森口哲朗、固体水素標的を用いた不安定核のスキン厚導出手法の開発、H28 年度 HIMAC 共
同利用研究成果発表会、ホテルポートプラザ千葉、2017/04/17-18.
36. S. Suzuki, Performance of time-of-flight detector and demonstration of completely new position
detector for mass measurements with the Rare-RI Ring, 10th International Conference on Nuclear
Physics at Storage Rings (STORI’17), Kanazawa, Japan, 13- 18 November 2017.
37. 鈴木伸司、RI 質量測定用の薄膜を用いた準非破壊的位置検出器の開発、日本物理学会第 73
回年次大会、東京理科大学野田キャンパス、2018 年 3 月 22-25 日.
38. 鈴木伸司, 質量測定用飛行時間検出器の大型実機の開発, 日本物理学会秋季大会、宇都宮大学、2017 年 9 月 12-15 日.
39. 向井もも、KISS II : 196−198Ir のレーザー共鳴イオン化核分光筑波、日本物理学会第 73 回年次
大会、宇都宮大学、2017 年 9 月 12-15 日.
40. Momo Mukai, Beta-ray detector in KISS, The inaugural symposium of the Tomonaga Center of theHistory of the Universe, University of Tsukuba, Mar. 26-27, 2018.
41. 山口貴之、Storage-ring mass spectrometry at GSI/FAIR、日本物理学会 2017 年秋季大会、宇都宮大学（峰キャンパス）2017.9.12-15.
42. Kimikazu Sasa, Seiji Hosoya, Tetsuya Matsunaka, Tsutomu Takahashi, Masumi Matsumura, Hangtao
Shen, Yasuji Oura, Keisuke Sueki, Isobar separation techniques of 41Ca AMS with the 6 MV tandem
accelerator, The Fourteenth International AMS Conference (AMS14), Ottawa (Canada), August 1418, 2017.
43. Kimikazu Sasa, Tsutomu Takahashi, Tetsuya Matsunaka, Seiji Hosoya, Masumi Matsumura, Hangtao
Shen, Maki Honda, Aya Sakaguchi, Keisuke Sueki, Mark Stodola, Mark Sundquist, Performance ofthe 6 MV multi-nuclide AMS system at the University of Tsukuba, The Fourteenth International AMS
Conference (AMS14), Ottawa (Canada), August 14-18, 2017.
44. Tetsuya MATSUNAKA, Kimikazu SASA, Seiji HOSOYA, Hongtao SHEN, Tsutomu TAKAHASHI,
Masumi MATSUMURA, Keisuke SUEKI, Radiocarbon measurement system using gas ion source andautomatic sample preparation system at the University of Tsukuba, The Fourteenth International AMS
Conference (AMS14), Ottawa (Canada), August 14-18, 2017.

7145. Tetsuya MATSUNAKA, Kimikazu SASA, Tsutomu TAKAHASHI, Seiji HOSOYA, Masumi
MATSUMURA, Keisuke SUEKI, Yukihiko SATOU, Radiocarbon variations since 1960 in tree rings
near the Tokai nuclear facilities in Japan, The Fourteenth International AMS Conference (AMS14),
Ottawa (Canada), August 14-18, 2017.
46. Seiji HOSOYA, Kimikazu SASA, Tsutomu TAKAHASHI, Tetsuya MATSUNAKA, Masumi
MATSUMURA, Hongtao SHEN, Keisuke SUEKI, Isobar suppression for 36Cl-AMS with the 6 MV
tandem accelerator, The Fourteenth International AMS Conference (AMS14), Ottawa (Canada),
August 14-18, 2017.
47. Hongtao SHEN, Kimikazu SASA, Ming HE, Baojian HUANG, Masumi MATSUMURA, Seiji
HOSOYA, Tetsuya MASUNAKA, Tsutomu TAKAHASHI, Maki HONDA, Keisuke SUEKI,
Qingzhang ZHAO, Qi MENG, Kejun DONG, Xiaoming WANG, Yijun PANG, Xianlin YANG,
Xiangdong RUAN, Shan JIANG, Study on Multiple radionuclides for Exposure Age Dating of Chinese
Tiankeng, The Fourteenth International AMS Conference (AMS14), Ottawa (Canada), August 14-18,
2017.
48. Masumi MATSUMURA, Kimikazu SASA, Tetsuya MATSUNAKA, Tsutomu TAKAHASHI, Seiji
HOSOYA, Keisuke SUEKI, Yukihiko SATOU, Hiroyuki MATSUZAKI, Contamination assessmentof chemical preparation rooms for I-129 AMS, The Fourteenth International AMS Conference(AMS14), Ottawa (Canada), August 14-18, 2017.
49. Qi MENG, Hongtao SHEN, Ming HE, Kimikazu SASA, Huang BAOJIAN, Masumi MATSUMURA,
Tetsuya MASUNAKA, Qingzhang ZHAO, Kejun DONG, Xiaoming WANG, Yijun PANG, Xianlin
YANG, Xiangdong RUAN, Shan JIANG, TianKeng Sample Preparation for 36Cl-AMS, The
Fourteenth International AMS Conference (AMS14), Ottawa (Canada), August 14-18, 2017.
50. Seiji Hosoya, Kimikazu Sasa, Tsutomu Takahashi, Maki Honda, Yukihiko Satou, Kenta Takano, Yuta
Ochiai, Koji Yamaguchi, Keisuke Sueki, Calusium-41 and Strontium-90 measurements with 6MV
AMS, The 7th East Asia Accelerator Mass Spectrometry Symposium (EA-AMS 7), Guangxi Normal
University, Guilin, China, November 20th to 25th 2017.
51. Hongtao Shen, Kimikazu Sasa, Qi Meng, Masumi Matsumura, Tetsuya Masunaka, Tsutomu Takahashi,
Seiji Hosoya, Keisuke Sueki, Ming He, Baojian Huang, Qingzhang Zhao, Kejun,Dong, Xiangdong
Ruan, Jiang Shan, Study on Cl-36 for Exposure Age Dating of Chinese Tiankeng, The 7th East Asia
Accelerator Mass Spectrometry Symposium (EA-AMS 7), Guangxi Normal University, Guilin, China,
November 20th to 25th 2017.

72

52. Yuta Ochiai, Kimikazu Sasa, Yuki Tosaki, Tsutomu Takahashi, Masumi Matsumura, Satomi Abe, Seiji
Hosoya, Kenta Takano, Yuki Ohta, Keisuke Sueki, Correlation between the 36Cl deposition flux andsolar activity, The 7th East Asia Accelerator Mass Spectrometry Symposium (EA-AMS 7), Guangxi
Normal University, Guilin, China, November 20th to 25th 2017.
53. Kenta Takano, Kimikazu Sasa,Tsutomu Takahashi, Yuki Tosaki, Yuki Ota, Seiji Hosoya, Yuta Ochiai,
Keisuke Sueki, Kazuho Horiuchi, 36Cl record in the Antarctic ice core around the cosmic-ray event of5480 BC and improved 36Cl AMS at the University of Tsukuba, The 7th East Asia Accelerator Mass
Spectrometry Symposium (EA-AMS 7), Guangxi Normal University, Guilin, China, November 20th to
25th 2017.
54. T. Matsunaka, S. Nagao, M. Inoue, S. Ochiai, K. Hayakawa, N. Tang, N. Suzuki, S. Ogiso, H. Ando,T. Shimotani, N. Hirohashi, M. Nishizaki, T. Morita, S. Miki, T. Aramaki, I. Kudo, N. Honda, T.
Takikawa, K. Sasa, M. Honda and K. Sueki, Anthropogenic iodine-129 and PAHs in seawater fromthe Japan Sea and the southern Okhotsk Sea, International Symposium “Environmental researches innorthern Japan Sea and related regions: Renewed horizon of Japan-Russia scientific partnership”
Shiinoki Cultural Complex, Kanazawa, Ishikawa Prefecture, 2018, March 3 to 4.
55. Tetsuya Matsunaka, Kimikazu Sasa, Keisuke Sueki, Akio Goto, Takahiro Watanabe, Yoshinori
Tuchiya, Nobuo Hirano, Miwa Kuri, Masaaki Takahashi, Kohei Kazahaya, Isoji Miyagi, Hiroyuki
Matsuzaki, Iodine isotopic composition in water from the crater lake and fumarolic area at Zao volcano,15th International Workshop on WATER DYNAMICS, Deeper and Hotter in Frontier Earth, Sendai,
Japan, 13-15 March, 2018.
56. 末木啓介、松尾一樹、笹公和、佐藤志彦、吉川英樹、箕輪はるか、福島第一原子力発電所事
故によって放出された放射性粒子中の放射性核種、日本放射線安全管理学会第 16 回学術大会、ホルトホール大分

大分県大分市、2017 年 6 月 28-30 日.

57. 笹 公和、高橋 努、細谷 青児、高野 健太、落合 悠太、松中 哲也、末木 啓介、極微量放射性核種を超高感度で検出可能な 6 MV タンデム加速器質量分析装置の開発、第 14 回日本加速器学会年会、北海道大学、2017 年 8 月 1 日～ 3 日.
58. 笹 公和、石井 聰、大島 弘行、高橋 努、田島 義一、大和 良広、森口 哲朗、上殿 明良、筑波大学タンデム加速器施設の現状報告、第 14 回日本加速器学会年会、北海道大学、2017
年 8 月 1 日～ 3 日.

73

59. 笹 公和、高橋

努、細谷 青児、高野 健太、落合 悠太、本多 真紀、太田 祐貴、松尾 一

樹、松中 哲也、坂口 綾、末木啓介、6 MV タンデム加速器質量分析装置を用いた長寿命

放射性核種の超高感度検出技術の開発、2017 年日本放射化学会年会・第 61 回放射化学討論会、筑波大学、2017 年 9 月 6 日～8 日.
60. 落合 悠太、笹 公和、高橋 努、戸崎 裕貴、松村 万寿美、安部 聡美、細谷 青児、高野 健
太、末木 啓介、福島第一原子力発電所事故前後における降水中の塩素 36 同位体比変動、
2017 年日本放射化学会年会・第 61 回放射化学討論会、筑波大学、2017 年 9 月 6 日～8 日.
61. 細谷 青児、笹
木

公和、高橋

努、本多

真紀、佐藤

志彦、高野

健太、落合

悠太、末

啓介、加速器質量分析法を用いた 90Sr 測定の試み、2017 年日本放射化学会年会・第 61回放射化学討論会、筑波大学、2017 年 9 月 6 日～8 日.
62. 松中 哲也、笹 公和、高橋 努、恩田 裕一、谷口 圭輔、脇山 義史、末木 啓介、福島の河川における 2013 年から 4 年間にわたる粒子状ヨウ素 129 のフラックス、2017 年日本放射化学会年会・第 61 回放射化学討論会、筑波大学、2017 年 9 月 6 日～8 日.
63. 高野 健太、笹 公和、太田 裕貴、高橋 努、細谷 青児、落合 悠太、末木 啓介、6MV タン
デム加速器質量分析装置における長寿命放射性核種 36Cl の検出感度の改善、2017 年日本放射化学会年会・第 61 回放射化学討論会、筑波大学、2017 年 9 月 6 日～8 日.
64. 本多 真紀、高久雄一、松崎 浩之、笹公和、末木 啓介、福島第一原子力発電所から放出された 129I の化学形態別分析、 2017 年日本放射化学会年会・第 61 回放射化学討論会、筑波大学、2017 年 9 月 6 日～8 日.
65. 笹 公和、山崎明義、石井 聰、黒澤正紀、冨田成夫、左高正雄、楢本 洋、工藤 博、構造材
料計測用マイクロイオンビーム分析装置によるビーム収束試験と材料組成分析、日本原子力学会「2017 年秋の大会」、北海道大学、2017 年 9 月 13 日～15 日.
66. 黒澤 正紀、笹 公和、石井 聰、丹沢花崗岩体の多相流体包有物の析出結晶、日本鉱物化学会 2017 年年会、愛媛大学、2017 年 9 月 12-14 日.
67. 池端 慶、服部浩一、黒澤 正紀、小室光世、笹 公和、石井 聡、三好陽子、島田和彦、戸塚修平、石橋純一郎、中部沖縄トラフ伊平屋北海丘熱水域に産する熱水変質鉱物の地球化学的研究、日本火山学会 2017 年度秋季大会、熊本大学黒髪南キャンパス、9 月 21 日～24 日.

7468. 松中哲也、長尾誠也、井上睦夫、落合伸也、森田貴己、三木志津帆、笹公和、本多真紀、末木啓介、放射性ヨウ素 129 を用いた日本海における海洋循環に関する研究、金沢大学・環日
本海域環境研究センター

共同利用シンポジウム「海流が繋ぐ日本海―オホーツク海の海洋

循環・物質循環の変動機構」、石川四高記念文化交流館、2017 年 12 月 13 日.
69. 松中哲也、長尾誠也、井上睦夫、落合伸也、早川和一、唐寧、森田貴己、三木志津帆、工藤勲、滝川哲太郎、笹公和、本多真紀、末木啓介、日本海－オホーツク海における放射性ヨウ素 129 と多環芳香族炭化水素の動態研究、2018 年 1 月 11 日

中央水産研究所.

70. 笹 公和、高橋 努、松中 哲也、細谷 青児、太田 祐貴、高野 健太、落合 悠太、本多 真紀、
末木 啓介、筑波大学 6 MV タンデム加速器質量分析装置による多核種 AMS と応用研究の現状、第 20 回 AMS シンポジウム、セラトピア土岐（岐阜県土岐市）、2017 年 12 月 14 日～
15 日.
71. 高野健太、笹公和、高橋努、細谷青児、落合悠太、戸崎裕貴、堀内一穂、末木啓介、南極ドームふじアイスコア中の 5480 BC イベント周辺における宇宙線生成核種 36Cl フラックス、
第 20 回 AMS シンポジウム、セラトピア土岐（岐阜県土岐市）、2017 年 12 月 14 日～15 日.
72. 細谷 青児、笹 公和、高橋 努、本多 真紀、佐藤 志彦、高野 健太、落合 悠太、末木 啓介、
6 MV タンデム加速器による 90Sr-AMS，第 20 回 AMS シンポジウム、セラトピア土岐（岐阜県土岐市）、2017 年 12 月 14 日～15 日.
73. 本多真紀、高久雄一、鹿籠康行、中野かずみ、松崎浩之、笹公和、高橋努、細谷青児、末木啓介、リアクションセル ICP-MS、ICP-MS/MS のための 129I 標準溶液の作製、第 20 回 AMS
シンポジウム、セラトピア土岐（岐阜県土岐市）、2017 年 12 月 14 日～15 日.
74. 太田祐貴、末木啓介、笹公和、高橋努、松中哲也、松村万寿美、戸崎裕貴、本多真紀、細谷青児、高野健太、落合悠太、佐藤志彦、吉川英樹、中間茂雄、箕輪はるか、福島原発周辺土
壌中の 36Cl の深度・蓄積量分布、第 20 回 AMS シンポジウム、セラトピア土岐（岐阜県土岐市），2017 年 12 月 14 日～15 日.
75. 落合悠太，笹公和，戸崎裕貴，高橋努，松村万寿美，本多真紀，細谷青児，高野健太，太田祐貴，末木啓介，つくば市における福島第一原子力発電所事故前後の 36Cl 降下フラックス変動，第 20 回 AMS シンポジウム，セラトピア土岐（岐阜県土岐市），2017 年 12 月 14 日～
15 日.
76. 落合悠太、笹公和、戸崎裕貴、高橋努、松村万寿美、細谷青児、高野健太、太田祐貴、末木啓介、つくば市における 36Cl 降下フラックス変動、第１９回「環境放射能」研究会、高エネ
ルギー加速器研究機構、2018 年 3 月 13 日‐15 日.

75

77. 笹公和、アイスコア中の宇宙線生成核種 Cl-36 の測定 - 宇宙線強度変動および環境変動と年代の指標として、研究集会「南極ドームふじ氷床深層アイスコアの解析による気候・環境変動の研究の新展開」、国立極地研究所３F

多目的会議室、2018 年 3 月 28－29 日.

78. I. Harayama, T. Tamura, K. Tsujita, Y. Watahiki, K. Ozeki, D. Sekiba, Study of PSD with energy
resolution for improvement of hydrogen sensitivity in high-resolution ERDA, (P1-10), 23rd
International Conference on Ion Beam Analysis, Fudan University, Shanghai (China), 8-13 October,2017.
79. 上ノ町水紀、辻田耕希、原山勲、杉澤悠紀、関場大一郎、島添健次、織田忠、高橋浩之、多チャンネル半導体と時間幅信号処理を用いた高分解能 ERDA 装置の開発、日本物理学会 第73 回年次大会

東京理科大学野田キャンパス、2018 年 3 月 22～25 日.

80. I. Harayama, T. Tamura, K. Tsujita, Y. Watahiki, D. Sekiba, Study of background noise in highresolution ERDA spectrum for improvement on detection limit of hydrogen, 第 18 回「イオンビー
ムによる表面・界面解析」特別研究会, 物質・材料研究機構

WPI-MANA 棟オーディトリア

ム, 2017 年 12 月 15～16 日.
81. 加藤悠、藤井一毅、原山勲、長倉直樹、関場大一郎、綿引悠美、山下了、陽子ビーム空間電
荷が引き起こすワイヤーチェンバーのゲイン低下評価、日本物理学会 2017 年秋季大会、宇都宮大学峰キャンパス、2017 年 9 月 12～15 日.
82. 長倉直樹、藤井一毅、原山勲、加藤悠、関場大一郎、綿引悠美、山下了、陽子ビーム空間電
荷が引き起こすワイヤーチェンバーのゲイン低下評価、日本物理学会 2017 年秋季大会、宇都宮大学峰キャンパス、2017 年 9 月 12～15 日.
83. 三島賢二、広田克也、家城斉、猪野隆、岩下芳久、北口雅暁、北原龍之介、古賀淳、森下彩、
長倉直樹、生出秀行、音野瑛俊、関義親、関場大一郎、嶋達志、清水裕彦、角直幸、角野浩
史、竹谷薫、富田龍彦、山田崇人、山下了、横橋麻美、吉岡瑞樹、J-PARC/BL05 における中性子寿命測定実験：実験の現状と最新結果、日本物理学会 2017 年秋季大会、宇都宮大学峰キャンパス、2017 年 9 月 12～15 日.
84. 北原龍之介、岩下芳久、清水裕彦、広田克也、横橋麻美、北口雅暁、山下了、山田崇人、家城斉、長倉直樹、角野浩史、吉岡瑞樹、音野瑛俊、富田龍彦、角直幸、森下彩、古賀淳、生出秀行、嶋達志、三島賢二、猪野隆、竹谷薫、関義親、関場大一郎、J-PARC/BL05 における中性子寿命測定実験：高統計測定に向けたビームラインアップグレード、日本物理学会 2017年秋季大会、宇都宮大学峰キャンパス、2017 年 9 月 12～15 日.

76

85. 辻田耕希、杉澤悠紀、原山勲、関場大一郎、高分解能 ERDA 測定に向けた 16 チャンネル位
置敏感検出器用プリアンプの開発、日本物理学会 2017 年秋季大会

岩手大学上田キャンパ

ス、2017 年 9 月 21～24 日.
86. 杉澤悠紀、原山勲、辻田耕希、関場大一郎、試作プリアンプと半導体検出器の組み合わせによる反跳水素の観察、日本物理学会 2017 年秋季大会

岩手大学上田キャンパス、2017 年 9

月 21～24 日.
87. 原山勲、関場大一郎、Qiang Zhao、Andre' Vantomme、Wilfried Van der Vorst、Johan Meersschaut、
PIXE の定量性向上に向けた相対補正因子 h factor を用いた構成方法の評価、日本物理学会
2017 年秋季大会

岩手大学上田キャンパス、2017 年 9 月 21～24 日.

88. 永田晃大、Development of a Support System for Radiation Resistance Testing, ISTS 31（宇宙技術および科学の国際シンポジウム）、松山市、2017.6.3 – 6.9.
89. 冨田成夫、浅川大樹、高橋勝利、 静電型イオンストレージリングを用いた電子-イオン散乱の研究、第 65 回質量分析総合討論会、つくば国際会議場 、2017/5/17-19.
90. Shigeo Tomita, Experiments on Interaction of Electrons with Biomolecular Ions using Electrostatic
Ion Storage Ring in KEK, 7th International Workshop on Electrostatic Storage Devices, Lyon, June 1922, 2017.
91. 冨田成夫、高速クラスターイオン照射による固体内電子の応答、TIA 連携プログラム探索推進事業シンポジウム

準相対論的巨大クラスターイオンビームが開く世界：ゲノム改変・極端非平衡材料創生に向けて、つくば国際会議場、2017/9/11-12.
92. 冨田成夫、高速クラスターイオン入射による固体内エネルギー付与過程、日本放射線影響学会

第 60 回大会、京葉銀行文化プラザ、 2017.10.26-28.

93. 椎名陽子、木下亮、松田誠、今井誠、川面澄、左高正雄、笹公和、冨田成夫、高速クラスタ
ー照射におけるコンボイ電子収量の標的膜厚依存性、第１２回先進原子力科学技術に関する連携重点研究討論会，量子科学技術研究開発機構 高崎量子応用研究所，2017 年 8 月.
94. 山崎明義、笹公和、石井聰、黒澤正紀、冨田成夫、上殿明良､筑波大学 6MV タンデム加速器
イオンマイクロビームシステムのビーム集束と元素分布測定、第 30 回タンデム加速器及びその周辺技術の研究会、セラトピア土岐、2017 年 7 月 6-7 日.

77

95. A. Yamazaki, K. Sasa, S. Ishii, M. Kurosawa, S. Tomita, H. Naramoto, M. Sataka, H. Kudo, S. Shiki,
M. Ohkubo, A. Uedono, Elemental Mapping Using the Ion Microbeam System on the 6 MV Tandem
accelerator at the University of Tsukuba, 3rd International Symposium for Innovative Measurement
and Analysis for Structural Materials, 産総研つくば中央、2017 年 10 月 3-5 日.
96. A. Yamazaki, H. Naramoto, K. Sasa, S. Ishii, M. Kurosawa, S. Tomita, M. Sataka, H. Kudo, M.
Ohkubo, A. Uedono, Imaging of Hydrogen in Thin Samples with Microbeam Transmission ERDA
Method, 3rd International Symposium for Innovative Measurement and Analysis for Structural
Materials, 産総研つくば中央、2017 年 10 月 3-5 日.
97. A. Yamazaki, H. Naramoto, M. Sataka, H. Kudo, K. Sasa, S. Ishii, H. Oshima S. Tomita, M. Ohkubo,
A. Uedono, Two-dimensional mapping of hydrogen and other elements in thin materials withmicrobeam-based transmission ERDA and PIXE, 23th International Conference on Ion Beam Analysis(IBA2017), Shanghai, China, 2017 年 10 月 8-13 日.
98. A. Yamazaki, K. Sasa, S. Ishii, S. Tomita, Y. Shiina, M. Kurosawa, H. Naramoto, M. Sataka, H. Kudo,
S. Shiki, M. Ohkubo, A. Uedono, Improvement of ion microbeam scanning system for realizing multimethod elemental analysis at the University of Tsukuba, 23th International Conference on Ion Beam
Analysis (IBA2017), Shanghai, China, 2017 年 10 月 8-13 日.
99. 山崎 明義、楢本洋、左高 正雄、工藤博、笹 公和、石井 聰、冨田 成夫、黒澤 正紀、

志岐 成友、大久保雅隆、上殿 明良、筑波大学 6MV タンデム加速器イオンマイクロビーム
システムにおけるビーム集束と He ビームによる PIXE-透過 ERDA 同時測定、33 回 PIXE シンポジウム、京都大学宇治キャンパス、2017 年 10 月 19-21 日.
100. H Latiff, M Kishimoto, S Sharmin, E Kita, H Yanagihara, T Nakagawa, Enhanced anisotropy intetragonalized (Cu,Co)Fe2O4 particles via the Jahn-Teller effect of Cu2+ ions, InterMAG Europe 2017,
Dublin, Ireland 24th - 28th April 2017.

78

6.4

UTTAC seminars

2017.5.17

Precision mass measurements of neutron-deficient nuclei in A ~ 60 − 80 region via
multireflection time-of-flight mass spectrograph, Souta Kimura (University of Tsukuba).

2017.6.16

Ice core record of 10Be from Dome Fuji, Antarctica revealing the history of cosmic-ray
variations, Kazuho Horiuchi (Hirosaki University).

2017.9.1

Measurement of jet spectra reconstructed with charged particles in Pb-Pb collisions at= 5.02 TeV with the ALICE detector at the LHC, Hiroki Yokoyama (University of√Tsukuba).

2017.10.23 Measurements of Azimuthal Angle Dependence of HBT Radii with respect to Event Plane in√2017.11.8= 2.76 TeV Pb-Pb Collisions at LHC-ALICE, Naoto Tanaka (University of Tsukuba).

Laser resonance ionization spectroscopy of 196−198Ir, Momo Mukai (University of Tsukuba).

2017.11.30 Measurement of the sixth order cumulant of net-proton multiplicity distributions in√
2018.1.15= 200 GeV Au+Au collisions, Toshihiro Nonaka (University of Tsukuba).

Measurement of elliptic flow at forward and backward rapidities in d+Au collisions at √= 200, 62.4, 39 and 19.6 GeV with PHENIX detector at RHIC, Kazuki Sato (University ofTsukuba).

2018.1.15

Measurement of soft-hard correlations with jets and the event plane in √= 2.76 TeV

Pb+Pb collisions at ALICE experiment, Yoshimi Rebaza (University of Tsukuba).
2018.1.15

Reaction Cross-section Measurement of proton drip line nucleus 17Ne using Solid Hydrogen
Target, Masamichi Amano (University of Tsukuba).

2018.1.15

Development of hard-to-measure nuclides measurements by Accelerator Mass Spectrometry
with the 6 MV tandem accelerator, Seiji Hosoya (University of Tsukuba).

2018.1.15

Cross wake field and correlated Head-Tail instability in beam-beam collision with a large
crossing angle, Nami Kuroo (University of Tsukuba).

79

7.
THESES

Doctor theses
Souta Kimura

Precision mass measurements of neutron-deficient nuclei in A 〜 60-80
region via multireflection time-of-flight mass spectrographMomo Mukai

In-gas-cell laser resonance ionization spectroscopy of 196-198Ir

Master theses
Masamichi Amano

Reaction Cross-section Measurement of proton drip line nucleus 17Ne using
Solid Hydrogen Target

Seiji Hosoya

Development of hard-to-measure nuclides measurements by Accelerator
Mass Spectrometry with the 6 MV tandem accelerator

Koki Tsujita

Development of high-sensitivity ERDA equipped with multi-channel
semiconductor detector

Naoki Yamamoto

Experimental study of electron – molecule scattering using electrostatic ion
storage ring

Undergraduate theses
Yuta Ochiai

Evaluation of temporal variation of cosmogenic 36Cl flux

Takeshi Mitsuhashi

Geochemical study of Iheya North Knoll hydrothermal field in the Okinawa
TroughRuri Suganuma

Production process of NO3 in atmosphere by cosmic rays

81

8.
LIST OF PERSONNEL

Tandem Accelerator Complex
A. Uedono

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

M. Sataka

Research Fellow

M. Matsumura

Research Supporter

S. Kuramochi

Administrative Staff

M. Satoh

Administrative Staff

H. Muromachi

Administrative Staff

Research Members1
Division of Physics
A. Ozawa

T. Moriguchi

K. Sasa

S. Suzuki

T. Yamaguchi (Saitama University [Cross-appointment])
Hongtao Shen (Guangxi Normal University, China [Visiting Foreign Research Fellow])
Division of Applied Physics
E. Kita

D. Sekiba

S. Sharmin

A. Uedono

H. Yanagihara

I. Harayama

S. Tomita

Division of Geoscience
M. Kurosawa

K. Ikehata

Division of Chemistry
K. Sueki

A. Sakaguchi

Division of Information and Systems
T. Kameda

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.

83

Staff of Open Advanced Facilities Initiative
H. KudoH. Naramoto

M. SatakaK. Awazu (National Institute of Advanced Industrial Science and Technology [AIST])S. Aoki (Comprehensive Research Organization for Science and Society [CROSS])
Staff of Joint Research Projects with Other Organizations
A. Yamazaki (Cross-ministerial Strategic Innovation Promotion Program [SIP])2
Y. Watahiki (Nanotech Career-up Alliance [CuPAL])
Graduate students
Graduate School of Pure and Applied Sciences
Graduate School of Life and Environmental Sciences
M. Ahmed

Y. Shiina

S. Kimura

M. MukaiM. Honda

Y. LiuR. PatelH. Latiff

Y. Hisamatsu

T. Tainosho

M. Matsumoto

E. Noguchi

D. Kamioka

T. Tamura

R. Tomita

T. Ojima

M. Amano

S. Hosoya

N. Yamamoto

K. TakanoY. OtaY. Sugisawa

J. Kikuda

T. Eguchi

Y. Hosoi

H. Onoda

K. Tsujita

A. Nagata

A. Yasuda

Y. Asai

K. Sako

K. Nakayama

N. Kuroo

S. Hashimoto

Y. Ochiai

K. Hattori

R. MaseT. Mitsuhashi

R. Suganuma

S. Yaguchi

W. UenoUndergraduates

S. AndoExternal users and collaborators
Y. Tosaki

National Institute of Advanced Industrial Science and Technology (AIST)

K. MasumotoHigh Energy Accelerator Research Organization (KEK)

T. MiuraHigh Energy Accelerator Research Organization (KEK)

H. Matsumura

High Energy Accelerator Research Organization (KEK)

Y. OuraTokyo Metropolitan University

T. HaraTokyo Metropolitan University

Y. Katou

The University of Tokyo

2

Also, a staff of Open Advanced Facilities Initiative84

N. Nagakura

The University of Tokyo

K. Fujii

The University of Tokyo

K. Ozeki

Ibaraki University

T. Matsunaka

Kanazawa University

K. Wakayama

Saitama University

H. Arakawa

Saitama University

K. Inomata

Saitama University

K. Nishimuro

Saitama University

T. Fujii

Saitama University

T. Kobayashi

Saitama University

R. Tanaka

Yamaguchi University

85