UTTAC-91, 2022

UTTAC
ANNUAL REPORT 2021

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

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

UTTACANNUAL REPORT 2021
UTTAC-91, 2022

April 1, 2021 − March 31, 2022

Editors : Tetsuaki Moriguchi, Kimikazu Sasa, Yoshihiro Yamato, Masumi Matsumura,
Masao Sataka, Hiroshi Naramoto, Eiji Kita, and Hiroshi Kudo (editor-in-chief)
UTTAC ANNUAL REPORT is a series of issues, which describes annual research
activities at Tandem Accelerator Complex, Research Facility Center for Science andTechnology, University of Tsukuba.
Copyright © 2021 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 forthe 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

Cover: Oblique-angle photo of the display for
operating the UTTAC 6MV tandem accelerator.

PREFACE
This annual report covers research and development (R&D) carried out at Universityof Tsukuba Tandem Accelerator Complex (UTTAC) during the fiscal year 2021 (1 April
2021 ~ 31 March 2022). The topics include not only accelerator-based R&D using the
6MV tandem and 1MV Tandetron accelerators, but also radioisotope-based R&D
employing positron annihilation spectroscopy and Mössbauer spectroscopy. Serious
influence on the UTTAC’s social activity by COVID-19 continued, in fact, there were no
student visitors from high schools in these two fiscal years. Nevertheless, R&D using theUTTAC facility has been successfully carried out, as reported here.
September 1, 2022
Editorial board

Cooperative experiments using the 6MV tandem accelerator. Students of the University ofTsukuba and from Saitama University are learning the data acquisition system.

-i-CONTENTS

1. ACCELERATOR AND RELATED FACILITIES
1.1

Accelerator operation 2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1

1.2

Approach to possible maximum energies of ions accelerated by the 6MV tandem accelerator

3

1.3

Present status of the Lamb-shift polarized ion source . . . . . . . . . . . . . . . . . . . .

5

1.4

Pilot study for visualizing accelerator activation with the portable γ -ray imaging device:
GeGI5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.

7

NUCLEAR AND ATOMIC PHYSICS
2.1

Measurement of the sign of nuclear moment for unstable nucleus 25 Al by using rotating
magnetic field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2

9Acceleration of polarized deuterons for observation of the nuclear magnetic resonance of
20 F. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.3

Development of a position-sensitive detector using scintillating fibers . . . . . . . . . . . 12

2.4

Spin polarized 19 O beam produced through low energy nuclear reaction using inverse
kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.

2.5

Development of PIXE system using superconducting tunnel junction X-ray detectors . . . 16

2.6

Measurement of convoy electrons produced by fast molecular ions in carbon foils . . . . . 17

ACCELERATOR MASS SPECTROMETRY
3.1

Status report of the Tsukuba 6 MV multi-nuclide AMS system in FY2021 . . . . . . . . . 19

3.2

Reconstruction of 129 I input history to the surface environment using a core from Beppu
Bay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.3

Development of a measurement technique for 135 Cs as a new oceanic circulation tracer . . 23

3.4

The performance of iodine-129 AMS measurements at the University of Tsukuba (FY2021) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.5

Vertical distribution and temporal changes of 129 I in soil derived from the Fukushima
Daiichi Nuclear Power Plant accident . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.6
4.

Surface distribution of iodine-129 in the Arctic Ocean . . . . . . . . . . . . . . . . . . . 29

ION-BEAM APPLICATIONS
4.1

Composition analysis of particles released from the FDNPP using microbeam scanning
PIXE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.2

Determination of H concentration in solids by T-ERDA . . . . . . . . . . . . . . . . . . . 32

4.3

Effect of LiCoO2 positive electrode insertion in all-solid-state Li-ion batteries investigated by NRA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

- ii -

5. ISOTOPE APPLICATIONS
5.1

Characterization of GaN grown by oxide vapor phase epitaxy by means of positron annihilation spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.2

Low temperature Mössbauer study on a hexagonal FeCo nitride . . . . . . . . . . . . . . 38

5.3

57 Fe Mössbauer spectra of La/Fe-Al O . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 3

5.4

Mössbauer study of Fe ions in ferrocene derivative-based assemblies on a graphene oxide40surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6. BEAM IRRADIATION EFFECT
6.1

Evaluation of radiation resistance of MPU and LoRa communication components forspace applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.2

Development of QCM sensor system for use in space . . . . . . . . . . . . . . . . . . . . 46

6.3

Unusual enhancement of self-field critical current density in YBa2 Cu3 O7 films by
severaltens-MeV Au ion irradiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

6.4

Study on mutagenesis with 15 N-resonant nuclear reaction and radiation effects . . . . . . 50

7. LIST OF PUBLICATIONS AND PRESENTATIONS
7.1

Peer-reviewed and proceedings papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

7.2

Reviews and books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

7.3

Poster and oral presentations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

7.4

UTTAC seminars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

8. THESES63

9. LIST OF PERSONNEL

65- iii -

1.
ACCELERATOR AND RELATED FACILITIES

Acceleration tube of the UTTAC 6MV tandem accelerator, viewed downfrom the central terminal to the high-energy end.

1.1

Accelerator operation 2021

K. Sasa, S. Ishii, T. Takahashi, Y. Yamato, Y. Tajima, M. Matsumura, T. Moriguchi
University of Tsukuba Tandem Accelerator Complex (UTTAC) is promoting the maintenance andoperation of a tandem accelerator facility consisting of the 6MV Pelletron tandem accelerator and the 1MV
Tandetron accelerator for cooperative researches both inside and outside the University of Tsukuba. In fiscal
2021, there were no cancellations nor postponements of machine time to prevent coronavirus infection. The
number of research projects and operation time of the accelerators increased from the last year [1].
In fiscal 2021, there were 12 research projects on campus and 9 research projects shared by facilities
outside the campus. The maintenance status of the facility is as follows. For the 6MV Pelletron tandem
accelerator, the RF charge exchange ion source (Alphatross) was maintained in the usual way and four TMPs
were overhauled. There was also a problem with the gas-stripper drive unit in the accelerator tank, which
has been repaired. The neutron area monitor in the Tandetron room was updated.
1MV Tandetron accelerator
The 1MV Tandetron accelerator has 2 negative ion sources and 4 beamlines. The operation time and theexperimental beam time were 644 and 286 hours, respectively, during the total service time in fiscal 2021.
The 1MV Tandetron accelerator was operated for a total of 68 days. A total of 39 research programs was
carried out and a total of 212 researchers used the 1MV Tandetron accelerator. Figures 1 and 2 showclassification of the accelerated ions and of experimental purposes, respectively.

Fig. 2. Experimental purposes of the 1MV Tandetron
accelerator in fiscal 2021.

Fig. 1. Accelerated ions by the 1MV Tandetron
accelerator in fiscal 2021.

6MV Pelletron tandem accelerator
The 6MV Pelletron tandem accelerator has 5 negative ion sources and 12 beamlines. The operation time
and the experimental beam time of the 6MV Pelletron tandem accelerator were 1,441 and 1,148 hours,
respectively, during the total service time in fiscal 2021. The operation time increased by about 34%
compared to the last year. The 6MV Pelletron tandem accelerator was operated for a total of 132 days. A

1total of 74 research programs was carried out and a total of 477 researchers used the 6MV Pelletron tandem
accelerator. Figure 3 shows the beam time histogram with respect to the terminal voltage. Figures 4 and 5
show classification of the accelerated ions and of the experimental purposes, respectively. The main fields
of application are accelerator mass spectrometry (AMS), ion beam analysis using microbeams, detector
developments, nuclear experiments using polarized beams, and radiation resistance tests for space devices.
In the acceleration test of the polarized deuteron beam from the Lamb shift type polarized ion source (PIS),
the degree of polarization was about 65% and the beam intensity was about 30 nA downstream of the PIS.
We performed Cs beam generation tests using the rubidium (Rb) sputtering negative ion source which is a
modified version of the S-5 ion source (MCG-SNICS) with the aim of developing AMS for Cs-135. The Rb
sputtering negative ion source can generate H− ions of 10 μA or more, and is also used as a normal negative
ion source.

Fig. 3. Beam time histogram as a function of the terminal voltage for the 6MV
Pelletron tandem accelerator in fiscal 2021.

Fig. 4. Accelerated ions for the 6MV Pelletron tandem
accelerator in fiscal 2021.

Fig. 5. Experimental purposes of the 6MV Pelletron
tandem accelerator in fiscal 2021.

Reference[1] K. Sasa et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 1.

2

1.2

Approach to possible maximum energies of ions accelerated by the 6MV
tandem accelerator

M. Sataka, T. Takahashi, H. Naramoto, H. Kudo, K. Sasa
Acceleration tests of ion beams obtained from the 6MV tandem accelerator at UTTAC have been
continued [1]. The experimental data of the highest energies of available ions is indispensable for radiation
resistance tests of semiconductors used in space [2]. Very weak beams are needed in these tests. On the other
hand, high intensity beam is important for ion irradiation experiment for material science such as ion beammodification of materials [3].
In this fiscal year, Fe and Ta ions were newly tested, while Al and Ni data were updated. We havemeasured beam currents of the accelerated ions as a function of the ion charge at terminal voltages from 3
to 6 MV. Figure 1 shows the beam current distributions of Fe ion as a function of the ion charge at the
maximum terminal voltage of 6 MV. Argon gas and a carbon foil were used as the strippers at the 6 MV
terminal. The gas pressure was about 5 μPa, and the thickness of the carbon foil was about 5 μg/cm2. The
ion current distribution for the foil stripper shifts to higher charge state by about 3 than for the gas stripper.
100

Ion Current (nA)

foil

gas

10

1

0.1
2

3

4

5

6

7

8

9

10

11

12

13

Charge State

Fig. 1. Ion beam current distribution of Fe ion for the terminal voltage of 6 MV. Both gas
and foil strippers were used at the high voltage terminal.
In the acceleration tests, negative molecular Al ions were injected towards the high voltage terminal. In

this case, the accelerated Al energy cannot be determined only by the terminal voltage and the ion charge
state of Al after acceleration. The maximum acceleration energy of 51 MeV was obtained in this test using
the gas stripper.
Table 1 shows the available beam current of Al, in addition to N, Ca, Sc, Ti, Mo, and W, which were
investigated until the last fiscal year. Table 2 shows the ion charges and maximum energies obtained for
injection of negative atomic ion at the terminal voltage of 6 MV, which have been accumulated from 2016
to 2021.

3

Table 1. Available beam current of ions obtained by molecular ion injection
at the terminal voltage of 6 MV, which have been accumulated since 2016.
The measured beam intensity is shown by the symbols: ○: ≥ 1nA, △: ≤1nA.
The data shown in red were collected by using foil strippers.
charge
state
14
13
12
11
10
9
8
7
6
5
4
3
2
1

N

Al

△
○
○
○
○
○
○

△
○
○
○
○

Ca

△
△
△
△
△

Sc

Ti

△
○
○
○
○
○
○
○
○
○
○

△
○
○
○
○
○
○
○
○
○
○

Mo

W

△
△
○
○

△
○
○
○
○
○
○

Table 2. Summary of the acceleration tests from 2016 to 2021 for negative atomic ion injection at
the terminal voltage of 6 MV. The measured beam intensities are shown by the symbols: ○: ≥ 1nA,△: ≤1nA. The data shown in red were collected by using 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

H

○

He

○
○

Li

○
○
○

B

○
○
○
○
○

C

○
○
○
○
○

O

○
○
○
○
○
○
○

F

○
○
○
○
○
○
○

Al

Si

○
○
○
○
○
○
○
○

△
○
○
○
○
○
○
○

S

△
○
○
○
○
○
○
○
○
○

Cl

△
○
○
○
○
○
○
○
○

Fe

△
○
○
○
○
○
○
○
○
○

Ni

Cu

△
○
○
○
○
○
○
○
○
○
○

△
○
○
○
○
○
○
○
○
○

Br

Ag

I

△
○
○
○
○
○
○
○
○
○

△
△
○
○
○
○
○
○
○
○

○
○
○
○
○
○
○
○
○

References[1] M. Sataka et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 3 and references therein.
[2] T. Shiobara et al., this Annual Report 6.2.
[3] M. Matsui et al al., this Annual Report 6.3.

4

Ta

Au

△
△

△
△
○
○
○
○
○

1.3

Present status of the Lamb-shift polarized ion source

T. Moriguchi, Y. Yamato, A. Ozawa, N. Kaname, A. Moriyama, A. Yano
The Lamb-shift polarized ion source (PIS) is one of the injectors for the 6MV Pelletron tandem accelerator which was installed as the new main machine at UTTAC in 2014 [1]. PIS, which was damaged
seriously by the 2011 disaster, was also newly reconstructed along with the installation of the new machine[2]. PIS can produce highly polarized negative proton and deuteron beams. Until now, the polarized protons have been mainly used to measure nuclear magnetic moments of unstable nuclei, while the polarized
deuterons were accelerated by the 6MV Pelletron tandem accelerator for the ﬁrst time in FY2021 [3]. In
this report, we refer to the present status of PIS.
For maintenance of the duoplasmatron (DP), we open the DP chamber and clean several electrodes atleast one time for every year to remove cesium deposits inside the chamber. As shown in Fig. 1 (a) and(b), the cesium deposits turn white around the electrodes. These deposits originate from cesium vapor
from the cesium cell, and cause discharges frequently. The present electrodes in DP are almost the sameas the replaced ones in 2018 [4]. The turbomolecular pump (TMP) used for DP was broken several times
so far. The present TMP shown in Fig. 1 (c) is of a magnetic levitation type (TG907M, Osaka Vacuum,Ltd.), which was installed in 2019, and has been stably operated. TMP of the electrostatic analyzer (ESA),
which is located downstream of PIS for 90◦ deﬂection of the beam, was also repaired because of cracks
in the bearing in 2020. The present cesium cell replaced the previous one in 2018 [4]. Immediately after
installing this cesium cell, the cesium leakage occurred and the cell was repaired in 2019. The beam
ﬂuctuation derived from two focus lenses downstream of an argon gas cell disappeared after grounding
their two electrodes using the two electrical resistors of 100 MΩ, as shown in Fig. 1 (d). The power supplyof the Wien ﬁlter (WF) was replaced by new one in 2021 because of deterioration of the previous one after
being used for more than 40 years. The spin ﬁlter (SF) is of signiﬁcance for nuclear polarization using
PIS. Since operation of the 6MV Pelletron tandem accelerator started, SF has been in stable operation
without serious troubles since it was constructed for the previous tandem accelerator at UTTAC in 1976
[5]. We are continuing to maintain PIS for its stable operation.
References[1] K. Sasa et al., UTTAC Annual Report 2014, UTTAC-84 (2015) 1.
[2] T. Moriguchi et al., UTTAC Annual Report 2014, UTTAC-84 (2015) 6.
[3] T. Moriguchi et al., this Annual Report 2.2.
[4] T. Moriguchi et al., UTTAC Annual Report 2018, UTTAC-88 (2019) 3.
[5] Y. Tagishi et al., Nucl. Instr. Meth. 164 (1979) 411.

5

!"#

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Fig. 1. (a) Cesium deposits around the aperture of the extractor in the DP chamber. (b) Cesium deposits
around the cesium cell. (c) The present turbomolecular pump for DP. (d) Two electrical resistors grounding
the two electrodes of focus lenses, indicated by yellow arrows.

6

1.4

Pilot study for visualizing accelerator activation with the portable γ-ray
imaging device: GeGI5

G. Yoshida1, H. Matsumura1, A. Toyoda1, T. Miura1, H. Nakamura1, K. Masumoto1, K. Sasa, T. Moriguchi,
M. Matsumura
Accelerator activation is a serious problem in terms of radiation protection of workers and waste
management of radioactive materials. There has been no method to evaluate the activation of accelerator
facility, except for direct survey with a γ-ray detector such as a scintillation survey-meter. Direct survey isinefficient and also of high risk of radiation exposure. The portable γ-ray imaging device (imager), which
has been rapidly developed since the Fukushima nuclear accident, can be supposed to be a breakthrough tovisualize the γ-rays from the radiation source, hence we have been tackling the application of this novel
instrument to evaluation of accelerator activation. Although there have been a variety of commercial γ-ray
imagers with different measurement methods and detector crystals, no model has responded to therequirements to evaluate accelerator activation; specification of activation sites, residual nuclides, and theiractivity. We conducted benchmark tests with various commercial devices assuming an actual accelerator
activation, and found the best candidate GeGI5 manufactured by PHDS Co., US-TN [1]. We areinvestigating the above requirements for evaluation of accelerator activation with GeGI5 at accelerator
facilities in Japan.
Currently, portable γ-ray imaging devices commercially available
employ one of three representative measurement methods: "pinhole","coded-mask", and "Compton-scattering" [2]. From the pre-selection
tests, we adopted GeGI5 (Fig. 1) which employs Compton-scattering
method as the best candidate for evaluating the accelerator activation.
Through the series of selection tests, we found that the most importantfactor is detection efficiency of the device. The detection efficiency of
GeGI5 was outstanding among the compared models equipped with arelatively large Ge single crystal of 90 mm diameter and 11 mm thickness.

Fig. 1. Overview of GeGI5.

According to our previous activation studies, the UTTAC facility would be ideal for a pilot study ofimaging device because activated areas are limited [3]. We measured activation of the beamlines of 6MV
tandem accelerator at UTTAC with GeGI5 just after stopping the acceleration of a proton beam. Short-lived
nuclei attributing to beam-loss were generated at certain places and we identified their locations by radiation
scanning with the survey-meter. From the screening result, we adopted the flexible joint at the middle of thebeamline as the target object for the imaging test. The maximum surface dose rate of the object was 3.5
μSv/h, and the principal radionuclide was 56Co. We obtained visualized images of the radiation source withchanging the measurement time and the distance between source and detector.
Figure 2 shows the time-lapse of visualized images of the radiation source. GeGI5 was set 40 cm distant

1Radiation Science Center, High Energy Accelerator Research Organization (KEK)7from the object. As a characteristic of the Compton-scattering method, arc shapes depending on incident γray energy and scattering angle are projected onto the screen at the 40 cm distance from the object. Color of
the arc reflects the number of overlaps (amount of statistics), in particular, the red area corresponds to themost probable site of the source. The arcs overlap at the flexible tube for about 30 minutes. Similar
measurements at different distances showed that the time required to identify the source sites is inversely
proportional to the square of the distance and can be standardized using statistics recorded by the device.

Fig. 2. Time-lapse of visualized images of the radiation source (activated flexible tube).

References[1] G. Yoshida et al., SORC2021, on-line (2021) 3K13.
[2] G. Yoshida et al., Environmental Radiochemical Analysis Ⅵ (2019) 183.
[3] G. Yoshida et al., Radiation Safety Management 20 (2021) 1.

8

2.
NUCLEAR AND ATOMIC PHYSICS

Plastic scintillation detector

2.1

Measurement of the sign of nuclear moment for unstable nucleus 25Al byusing rotating magnetic field

A. Ozawa, T. Moriguchi, Y. Yamato, N. Kaname, A. Moriyama, A. Yano
We developed rotating magnetic field system to determine the sign of nuclear magnetic moments (μ’s)
for unstable nuclei. In FY2020, we have succeeded in determining the positive sign of μ for 29P (Iπ=1/2+)[1]. In FY2021, we confirmed the sign of μ for 29P based on the sign of μ of 20F, which is known to bepositive [2]. Furthermore, based on the sign of μ for 29P, we determined the sign of μ for 25Al(Iπ=5/2+).
Our rotating magnetic field system is presented in Ref. [3]. If the β-NMR effect disappears in a clockwise(counterclockwise) rotating magnetic field when the static magnetic field is downward, the sign is positive(negative). In our system, we use cross coils to generate a rotating magnetic field, and we put a cable delay
between the two high frequency systems to create a phase difference between the cross coils. The phasedifference produces the clockwise (or counterclockwise) rotating magnetic field. The experiment was
conducted at the 6MV tandem accelerator at UTTAC. In the 29P confirmation experiment, the polarized
deuteron beam was accelerated to 6 MeV and the CaF2 target was irradiated to generate polarized 20F. The
static magnetic field was set to ~4.3 kG with downward, and RF was set to ~3.3 MHz including the Larmor
frequency of 20F in this magnetic field. This frequency corresponds to a period of ~320 ns. The β-NMR
effect for 20F disappeared when we put ~250 ns cable delay. Next, a polarized deuteron beam was applied
to the Si target to generate polarized 29P. The static magnetic field was set to ~1.7 kG and RF was set to ~3
MHz including the 29P Larmor frequency in this magnetic field. The β-NMR effect for 29P disappeared whena cable delay of ~270 ns was inserted. Since the β-NMR effect for 29P disappeared with almost the samecable delay as in the case of 20F, it was confirmed that μ for 29P is of the same positive sign as for 20F. Next,
the sign measurement for 25Al was performed with 29P as a reference. The polarized proton beam wasaccelerated to 12 MeV and irradiated to the Si target to generate polarized 29P. The static magnetic field was
set to ~3.5 kG with downward, and RF was set to ~6.7 MHz including the 29P Larmor frequency in thismagnetic field. This frequency corresponds to a period of ~155 ns. The β-NMR effect for 29P disappeared
when we put a delay of ~10 ns. Next, a polarized proton beam was applied to the Si target to generatepolarized 25Al. The static magnetic field was set to ~6 kG, and RF was set to ~6.6 MHz including the 25Al
Larmor frequency [4] in this magnetic field. The β-NMR effect for 25Al disappeared when a delay of ~20 ns
was inserted. Since the β-NMR effect disappeared with almost the same delay as in the case of 29P, it isshown that μ for 25Al is of the same positive sign as for 29P. The positive sign for 25Al is consistent withprediction by the Schmidt value (μ=+4.7926 n.m.) for the nucleus (odd Z, l=2).
References[1] A. Ozawa et al., UTTAC Annual Report 2020 (2021) 7.
[2] T. Tsang and D. Connor, Phys. Rev. 132 (1963) 1141.
[3] K. Tomita et al., UTTAC Annual Report 2019 (2020) 8.
[4] N. J. Stone, Atomic Data and Nuclear Data Tables 90 (2005) 75.

9

2.2

Acceleration of polarized deuterons for observation of the nuclear
magnetic resonance of 20 F

T. Moriguchi, Y. Yamato, A. Ozawa, N. Kaname, A. Moriyama, A. Yano
The Lamb-shift polarized ion source (PIS) at UTTAC is able to produce highly polarized proton anddeuteron beams [1, 2]. Since the operation of the 6MV Pelletron tandem accelerator was started, polarized proton beams from PIS have been mainly used to measure nuclear moments of unstable nuclei [3-8].
So far, acceleration of polarized deuteron beams has been limited because of the induced radioactivity.
According to the recent report, the air dose rate during the irradiation of deuteron beams under the certification in UTTAC is less than that of proton beams [9]. In FY2021, we performed acceleration of polarized
deuterons for the first time with the 6MV Pelletron tandem accelerator to observe the nuclear magnetic
resonance (NMR) of an unstable nucleus 20 F (t1/2 = 11.0160 sec [10]).
To maximize beam currents from PIS, we optimized the several parameters of PIS. The beam currents
were measured by the Faraday cup (FC-PIS), which is located just downstream of PIS. Figure 1 shows
beam currents of proton and deuteron beams measured by varying the magnetic field of the spin filter [1,2]. The two peaks around 540 and 605 Gauss correspond to the resonances of the nuclear spin magnetic
quantum number mI = +1/2 and –1/2 for protons, respectively, and three peaks around 565, 575, and 585
Gauss correspond to those of mI = +1, 0, and –1 for deuterons, respectively. Under the optimal condition,
the beam current of polarized deuterons is approximately 40 nA, which is about seven times larger thanthat reported previously [11]. Furthermore, the resonance peaks of deuterons in Fig. 1 have become
narrower than those reported previously [11]. The polarization of the polarized deuterons was ∼60% with

180
160
140
120
100
80
60
40
20
520

ProtonmI=+1/2 DeuteronmI=-1/2

mI=+1 mI=0 mI=-1

540

560
580
600
Magnetic field (G)

60
55
50
45
40
35
30
25
20
15
620

Beam current of deuteron (nA)

Beam current of proton (nA)a quenching method [2].

Fig. 1. Beam currents on the Faraday cup (FC-PIS) as a function of the magnetic field of the spin filter.
Closed and open circles indicate beam currents of proton and deuteron, respectively.

For production of 20 F and observation of its NMR, polarized deuteron beams were accelerated up to
6 MeV by the 6MV Pelletron tandem accelerator, and transported to the A6 course. In this experiment,
the transport rate from the FC-PIS to the Faraday cup of A6 course (FC-A6) was approximately 40%, andthe beam current on FC-A6 was ∼13 nA. For both PIS and the beam transport line, optimized transport isnecessary to reduce the beam loss. A CaF2 stopper installed in the vacuum chamber of the A6 course was10! p) reaction. β rays emitted from
irradiated with polarized deuteron beams to produce 20 F via the 19 F(d,20 F were detected by two sets of plastic scintillation counters placed above and below the stopper. Figure 2(a) shows a typical β -ray time spectrum. By taking into account the lifetime of 20 F, the experimental data
can be successfully fitted, as shown in Fig. 2 (a). From this result, the production of 20 F was confirmed
using the polarized deuteron beams. Following this confirmation, we attempted to observe NMR of 20 Fwith the NMR system associated with β -rays (β -NMR system) [3]. The CaF2 stopper surrounded by
the RF coil was placed in the static magnetic field of 0.43 T. Recently, a variable condenser for tuning
the resonance frequency was improved to be controlled remotely with a brushless motor and its driver(BLM230HP-GFV and BMUD30-A2, Oriental motor Co., Ltd.). Figure 2 (b) shows the asymmetry of
the number of β rays counted by up and down plastic scintillation counters as a function of RF frequency.
Considering the RF-Off level, the NMR peak has been successfully observed around 3.3 MHz, whichis equal to the Larmor frequency of 20 F, corresponding to the nuclear magnetic moment of 20 F alreadyreported [12]. From this result, we confirmed the polarization of 20 F using the polarized deuteron beams.
In Ref. [13], we report the measurement of the sign of the magnetic moment for 20 F with the rotating
magnetic field [6].
(b)(a)
1.0e+7

1.025

Exp.
20
F
Const.
Total

Counts

1.0e+51.0e+4

RF-Off

1.020
Asymmetry (a.u.)

1.0e+6

1.0e+31.0e+2

1.015
1.010
1.005

1.0e+11.0e+0
0

50

100

150

200

250

1.000
2.8

300

3.0

Time (sec)

3.2
3.4
Frequency (MHz)Fig. 2. (a) Typical β -ray time spectrum and (b) β -NMR effects of 20 F.

References[1] Y. Tagishi et al., Nucl. Instr. Meth. 164 (1979) 411.
[2] T. Moriguchi et al., Proceedings of Science, PSTP2017 (2018) 018.
[3] A. Ozawa et al., UTTAC Annual Report 2017, UTTAC-87 (2018) 7.
[4] A. Ozawa et al., UTTAC Annual Report 2018, UTTAC-88 (2019) 7.
[5] A. Ozawa et al., UTTAC Annual Report 2019, UTTAC-89 (2020) 7.
[6] K. Tomita et al., UTTAC Annual Report 2019, UTTAC-89 (2020) 8.
[7] A. Ozawa et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 7.
[8] A. Yano et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 8.
[9] T. Moriguchi et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 5.
[10] D. P. Burdette et al., Phys. Rev. C 99 (2019) 015501.
[11] T. Moriguchi et al., UTTAC Annual Report 2016, UTTAC-86 (2017) 3.
[12] N. J. Stone, At. Data Nucl. Data Tables 90 (2005) 75.
[13] A. Ozawa et al., this Annual Report 2.1.

11

3.6

3.8

2.3

Development of a position-sensitive detector using scintillating fibers

T. Yamaguchi1,2 , M. Kanda2 , H. Seki2 , N. Shinozaki2 , M. Otsu2 , Y. Koizumi2 , S. Matsuda2 , K. Okubo2 ,K. Sasaki2 , S. Sugimoto2 , A. Yanai2 , T. Suzuki2 , T. Moriguchi, A. Ozawa, N. Kaname, A. Yano
We have been developing the Rare-RI Ring facility [1] at the RI Beam Factory in RIKEN for precisionstorage-ring mass spectrometry of short-lived exotic nuclei relevant to the astrophysics r-process scenario.
Since the Rare-RI Ring is coupled with the cyclotron facility and hence individually stores a single ionof interest in-flight selected at the fragment separator, conventional beam diagnostic devices are often
difficult to be employed. Besides, a long injection beam line is equipped to realize such a unique injection
scheme. As such many beam diagnostics detectors, which can be easily operated and maintained and witha low cost, are required. We designed several shaped plastic scintillation detectors for position detection,and tested with swift heavy ions at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility [2] andwith 12-MeV protons at the 6MV tandem accelerator at UTTAC. In particular, general versatility of thedetector performance was examined with a low-energy beam.
In the previous annual reports in 2017 [3] and 2018 [4], we reported two kinds of position-sensitive
detectors. The first case is a beam line detector, which consists of thin plastic scintillator bars (3 mmwide, 100 mm long, and 3 mm thick) vertically arranged to a flat plane (20 bars for 60 × 100 mm2 ) and acommon light guide connected to both ends. The scintillation photons are read out by four photo sensors
at four corners: left-up (LU), left-down (LD), right-up (RU), and right-down (RD), through the common
light guides. The time difference and pulse height difference of both ends were correlated well with thebeam position. As a result, a position resolution of 1.7 mm (σ ) in the y-direction was obtained at the
HIMAC experiments [5].
To upgrade this detector, we use a simple plastic scintillator plate (100 × 100 mm2 and 3 mm thick)instead of the bar array structure and three bundled wavelength shifters (each 1 × 1 mm2 , Kuraray Y-11)
instead of one light guide, which is an easy and cheap solution, as shown in the inset photo in Fig. 1.
For a 200-MeV/u Kr beam at the HIMAC facility, a position resolution of 1.2 mm (σ ) in the y-direction
was obtained from the pulse height difference. Figure 1 (left panel) shows a correlation plot of beamprofile in the y-direction measured with PPAC [6] and that with the present detector, where a pulse heightratio is defined as Ey = (QLU − QLD + QRU − QRD )/(QLU + QLD + QRU + QRD ). Here, Qi means an integrated charge measured with a charge-sensitive analog-to-digital converter, and the subscript i means eachposition of the photo sensors as described above. A linear relation in a wide range has been achieved.
However, a large distortion in the x-direction was found, which needs to be improved. An experimentwith a 12-MeV proton beam was conducted to investigate the detector performance. Figure 1 (right panel)shows a correlation plot of beam position in the y direction and the Ey ratio defined above. The beam position collimated to a 5-mm diameter was changed by moving the detector set up on a remotely-controlled
movable platform. A linear correlation was confirmed, but a position resolution more than 10 mm wasobserved. We are currently improving the detector further.
As the second case, we produced a prototype of a long scintillating fiber detector to observe de1 Cross appointment
2 Department of Physics, Saitama University

12

'!ratio()*+,$-.&Ey(arb)

Ey ratio (arb)

PPAC y (mm)y position (mm)!"#$%%&

Fig. 1. Left: A two-dimensional correlation plot of the y-direction beam profile measured with PPAC andthat with the present detector at HIMAC. A pulse height ratio, Ey , is well correlated to the beam position.
Right: the same but with a 12-MeV proton beam at Tsukuba. The inset shows a photo of the present
detector without photosensors.

cay particles of stored ions in the Rare-RI Ring. The detector will be installed in the vacuum chamber along the circumference of the storage ring. The original concept and results of experiments conducted at the HIMAC facility were published elsewhere [7]. The prototype consisting of nine scintillatingfibers (Kuraray SCSF-78J, 2 × 2 mm2 and 2 m long) was arranged to form a flat plane of 18 mm × 2
m. Each end of the nine scintillating fibers was assembled and connected to a common photo sensor.
The results of the 12-MeV proton beam test show the position resolution of a few cm from the ratio
Tratio = (Tleft − Tright )/(Tleft + Tright ), where Tleft(right) indicates the timing of the left (right) photo sensor
measured with a time-to-digital converter.
To upgrade this fiber detector, we use several plastic scintillator plates (100 × 39 mm2 and 5 mm
thick) and several wavelength shifters (WLS) for scintillation readout. The WLS are embedded on theback surface of the plastic plates. The advantage of the simple plate structure is to measure energy lossof decaying particles, which helps particle identification capability. A beam test with 12-MeV protons
showed a position resolution of 5 cm, while that with 400-MeV/u Kr showed a position resolution of 5mm, which is good enough to be applied at the Rare-RI Ring.
References[1] A. Ozawa et al., Prog. Theo. Exp. Phys. 2012 (2012) 03C009.
[2] M. Kanazawa et al., Nucl. Phys. A 746 (2004) 393c.
[3] T. Yamaguchi et al., UTTAC Annual Report 2017, UTTAC-87 (2018) 9.
[4] T. Yamaguchi et al., UTTAC Annual Report 2018, UTTAC-88 (2019) 8.
[5] K. Wakayama et al., JPS Conf. Proc. 35 (2021) 011024.
[6] H. Kumagai et al., Nucl. Instrum. Methods Phys. Res. B 317 (2013) 717.
[7] K. Inomata et al., JPS Conf. Proc. 35 (2021) 011021.

13

2.4

Spin polarized 19 O beam produced through low energy nuclear reaction using inverse kinematics

M. Mihara1 , Y. Otani1 , Y. Kimura1 , T. Sugisaki1 , T. Moriguchi, A. Yano, K. Tomita, N. Kaname, A.
Ozawa, H. Ishiyama2 , M. Fukutome1 , G. Takayama1 , R. Uda1 , H. Yuta1 , M. Fukuda1 , K. Matsuta1
Nuclear magnetic resonance (NMR) spectroscopy of oxygen is usually difﬁcult to perform becauseof its low sensitivity due to very small natural abundance of 17 O (0.04%) which is the only nucleus with
nonzero nuclear spin among the stable oxygen isotopes. As a new alternative method to 17 O NMR formaterials science and other applications, we are attempting to use β -ray detected NMR (β -NMR) spectroscopy, which shows ultra-high sensitivity by using short-lived radioisotopes (RIs). In this study, 19 O (I= 5/2. T1/2 = 16.9 s) which is a promising β -NMR probe nucleus was produced by a low-energy neutrontransfer (d, p) reaction in inverse kinematics to provide a spin-polarized 19 O beam.
The experiment was continued since 2020 at the A7 course of the UTTAC facility using the apparatus
shown in Fig. 1 [1]. An 18 O4+ beam with an energy of 30 MeV and an intensity of 100−200 nA wasprovided by the 6MV tandem accelerator at UTTAC to irradiate a deuteron target. Deuterium-absorbed
titanium foil TiDx with a thickness of 1 µ m was used as the deuteron target, which was prepared by heating
the Ti foil at 400 ◦ C for about 75 minutes in a deuterium gas atmosphere with a pressure of about 220 Torr.
The target was ﬁxed to a Cu holder attached to a water-cooled ﬂange and the beam was collimated by aCu holder of 3 mm diameter. The target chamber was ﬁxed to a rotating table so that only the directionof the vacuum duct could be changed while the target position was ﬁxed. A welded bellows was used toconnect the target chamber to the upstream beamline so that the target chamber can rotate freely.
19 O nuclei produced by the d(18 O, 19 O)p reaction were stopped in a single crystalline TiO sample
2
19
and spin polarization of O was measured as a function of the emerging angle θ . For this measurement,

an ultra-compact β -NMR spectrometer, which was newly fabricated for this study, was installed at thedownstream side of the chamber. The performance of this instrument has already been conﬁrmed usinga spin-polarized 19 O beam at HIMAC in the Institute for Quantum Medical Science [2]. Polarization (P)of 19 O was obtained by measuring the β -ray asymmetry AP, where A(= −0.7 for 19 O) is the β -decay
asymmetry parameter. The cycle of 40 s of the beam irradiation and 40 s of the β -ray measurement was
repeated, and once in every two cycles, polarization was inverted via the adiabatic fast passage (AFP)by applying an RF magnetic ﬁeld between the beam irradiation and measurement periods. β -rays werecounted by counter telescopes placed at the top and bottom of the sample, respectively. Using the counting
ratio ron (roff ) of these telescopes for the cycle with (without) RF, the β -ray asymmetry can be obtained√√by AP = ( R − 1)/( R + 1), where R = roff /ron .
Figure 2 shows the result of AP and β -ray yield of 19 O plotted as a function of θ , taken for both theleft and right directions viewed from upstream of the beam. This indicates signiﬁcant polarization withthe absolute value of |AP| ∼2% at around θ = 5.4◦ , and when the angle is reversed from the left to right
direction, the sign of AP is reversed from positive to negative. The present result is in very good agreementwith the θ and AP values predicted from the previous result of 19 O polarization in forward kinematics [3].
1 Department of Physics, Osaka University
2 RIKEN Nishina Center for Accelerator-Based Science

14

The energy of 19 O emitted in the direction of θ = 5.4◦ ± 0.4◦ , where the polarization maximum wasobserved in the present study, is estimated to be (25 ± 2) MeV by the kinematics. This corresponds toabout 15 µ m in terms of range in Si.
Using the polarized 19 O beam with the above condition, we have measured the spin-lattice relaxation
time of 19 O in Y2 O3 stabilized ZrO2 (YSZ) which is used as fuel cell materials, in order to study theproperty of oxide ion conduction [4]. In conclusion, it has been demonstrated that a polarized 19 O beamwith nearly uniform energy can be obtained by using the low energy nuclear reaction in inverse kinematics,
which is useful for materials science studies.
!

3"4#$$-/+,+)0.$+,12&+,-.&+$34,51&(,$3/22)5,+/3/57,3+$C;D%?$=7&3+-/5&+&-!"#$$#! %&#$$'
!%!
!"!#$

!

"#$%&'
8&29&9$1&22/8=:,21,34;,--,<$
7&-5,0&0+$5,.0&+()*! +,-.&+

6,7+/0$8)09/8!%#5$ .6/(7'@?E$7)7&()*++,+-(./*0#
1/-2
"#$$φ

?@$3/)2
AB$4/29&-=)0.2&$3-<=+,22)0&$()!&' 72,=+)3$=3)0+)22,+)/0$>)1&-

Fig. 1. Apparatus of the present experiment to measure 19 O polarization via the d(18 O, 19 O)p reaction.

!"

#"
19

left
right

AP (%)

18

E[ O] = 30 MeV!-ray yield (arb.)18d ( O, O) p

2
0
-2
3

4

5

6

7

8

60
40
20
0
3

4

5

! (°)

6

7

8

! (°)

Fig. 2. a) β -ray asymmetry AP and b) β -ray yield of 19 O produced in the d(18 O, 19 O)p reaction measured
as a function of the emerging angle θ . The left (right) indicates the case where the 19 O nuclei are emitted
in the left (right) direction when viewed from the upstream of the beam. The sign of AP is deﬁned positivein the vertical upward direction.

References[1] M. Mihara et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 10.
[2] Y. Kimura et al., Hyperﬁne Interactions 243 (2022) 1.
[3] K. Matsuta et al., Nucl. Instrum. Methods A 402 (1998) 229.
[4] Y. Otani et al., Hyperﬁne Interactions 242 (2021) 47.

15

2.5

Development of PIXE system using superconducting tunnel junction
X-ray detectors

S. Shiki1, S. Tomita, S. Ishii, S. Hatada, K. Sasa
Superconducting tunnel junction (STJ) detector is promising for soft X-ray spectroscopy due to its highsensitivity, high energy resolution, and high counting rate [1]. Particle Induced X-ray Emission equippedwith superconducting tunnel junction detector array (SC-PIXE) will expand the energy coverage of PIXE
into soft X-ray region where light elements are visible. The present paper reports the first measurement ofphoton using the SC-PIXE system which is set up in the μ-beam line at UTTAC [2].
The details of the experiments are as follows. The STJ spectrometer consists of a helium-3 cryostat, an
STJ detector array of 512 pixels, 16-channel charge sensitive amplifier, multichannel analyzer having 16inputs, and the μ-beam transport system. The
temperature of the cold stage can be cooled down toapproximately 320 mK. The beam current of proton
was approximately 1 nA. The distance from the beam
spot to the STJ detector was approximately 100 mm.
The test sample was an aluminum plate.
Figure 1(a) shows a pulse height spectrum of an
STJ pixel. We see two clear peaks at pulse heights ofabout 400 and 1500 on a broad continuum. These peaks
are due to C-Kα and Al-Kα lines, respectively. The
origin of the continuum might be protons which arescattered on the sample and absorbed by the Si

Fig. 1. (a) Pulse height spectrum of an STJ pixel.
(b) Pulse height spectrum of an STJ pixel after
rejection of coincidence events to neighbor pixels.

substrate. A part of phonons generated by a proton create a pulse signal when the Cooper pair in the
superconducting film of STJ pixel is broken by the phonons. Figure 1(b) shows a pulse height spectrum of
the STJ pixel after rejection of the coincidence events of neighbor pixels. In this case, the peaks are seen
without the background of broad continuum. The energy resolution of Al-Kα line is about 50 eV, which is
better than that of high-quality semiconductor detectors. Continued research is needed to complete the SCPIXE as a standard method of material analysis.
References[1] S. Shiki et al., J. Low Temp. Phys. 167 (2012) 748.
[2] A. Yamazaki et al., Nucl. Instr. Meth. Phys. Res. B 404 (2017) 92.

1

National Institute of Advanced Industrial Science and Technology

16

2.6

Measurement of convoy electrons produced by fast molecular ions incarbon foils

S. Tomita, M. Hiraga, S. Hatada, S. Ishii, T. Takahashi, K. Sasa, Y. Shiina1
The dynamic response of electrons in material caused by injection of fast molecular ions attracts certain
attention because the response is related to the transport mechanism of the scattered electrons underinteraction with the projectile ion. This leads to non-linear electron yield, which is called the cluster effectfor molecular ion injections. We have investigated especially the yield of convoy electrons under injectionof fast molecular ions [1, 2]. The convoy electron is the electron emitted in the same direction and with thesame velocity as the projectile ions. The convoy electron yield 𝑌 C
𝑌 C

shows a strong nonlinear effect of+∝ 𝑛 for 3.5 MeV/atom Cn ions. To study the characteristic effect in the low-energy region. We

have developed an apparatus of zero degree electron spectroscopy adapted to 1MV Tandetron at UTTAC.
The schematic drawing of the experimental setup is shown in Fig. 1. Ions accelerated with 1MV
Tandetron were injected into the experimental chamber. The chamber was surrounded by a triaxial square
Helmholtz coil to eliminate the Earth’s magnetic filed [3]. The electrons produced by penetration of the ionsin the foil were deflected by an electrostatic deflector, and the energy was analyzed with an electron
spectrometer. The relative resolution of the spectrometer was 3.3%. The beam current of projectile ionspassed through the electrostatic deflector was monitored by the Faraday cup located downstream of thebeam line. Since the average charge of the transmitted ion depends on the thickness of the target foil as wellas the cluster size of the projectile, we employed a beam-monitor system with Au bulk target. This target
was fixed on the device with metronomic movement [4], thereby the incident beam crossed the Au target
and the empty frame towards the foil target alternately. The amount of back-scattered ions were detectedwith SSD located at 150 degree to normalize the electron yield.
The measured electron energy spectrum is shown in Fig. 2 for incident ions of C+ and C2+ with an energyof 437 keV/atom. The electron yield is normalized to the number of injected atoms. The peak located aroundFig. 1. Schematic drawing of the experimental setup.

1

Rikkyo University

17

15 eV is due to convoy electrons, which have almost the same velocity as the 437 keV carbon ion. The
amount of C2+ is twice that of C+, as previously reported [1].

Fig. 2. Energy spectrum of zero-degree electrons emitted from a carbon foil of 11.2 μg/cm2 in thickness.

References[1] S. Tomita et al., Phys. Rev. A 73 (2006) 060901.
[2] Y. Shiina et al., Nucl. Instr. Meth. Phys. Res. B 460 (2019) 30.
[3] S. Tomita et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 14.
[4] R. Ishiwari et al., Nucl. Instr. Meth. Phys. Res. B 47 (1990) 111.

18

3.
ACCELERATOR MASS SPECTROMETRY

From the backyard of UTTAC

Maintenance and inspection of switchboards

3.1

Status report of the Tsukuba 6 MV multi-nuclide AMS system in FY2021

K. Sasa, T. Takahashi, M. Matsumura, D. Shiine, A. Sakaguchi, K. Sueki
The Tsukuba 6 MV multi-nuclide AMS system was operated for a total of 51 days and 530 hours infiscal 2021. Figure 1 shows monthly-measured rare nuclides from April 2021 to March 2022. We measured
469 samples in total dealing with rare radionuclides such as 36Cl and 129I, as shown in Table 1.
90

Cl-36

80

I-129

Number of pieces

70
60
50
40
30
20
10
0
Apr-21 May-21 Jun-21

Jul-21

Aug-21 Sep-21

Oct-21 Nov-21 Dec-21 Jan-22 Feb-22 Mar-22

Monthly measured nuclides
Fig. 1. Monthly-measured nuclides from April 2021 to March 2022.
Table 1. Number of measured 36Cl and 129I samples in fiscal 2021.

Item
Cl-36
I-129
Sub total
36

Reagent & Blank
samples15
93108Standard samples

Unknown samples

12
89
101

15
245
260

Total
42
427
469

Cl-AMS
36

Cl-AMS was applied for tracing cosmic ray events remaining in the ice-core in fiscal 2021 [1]. We

have started analysis of Cl-36 in the relatively recent ice cores of the Antarctic H15 shallow core. The 36Cl/Cl
background and ice-core samples have been measured since fiscal 2021 under the beam condition of 36Cl7+
with 48.0 MeV using a carbon foil stripper. The background ratios of 36Cl/Cl ~ 3 × 10−15 were achieved with
AgCl blank samples by using 36Cl7+ [2].
129

I-AMS
129

I-AMS was mainly used for investigations of the radioactive contamination in surface soils, water

samples, dissolved matters in the river at Fukushima and the tracer for oceanic circulation with a total of
245 unknown samples in fiscal 2021.

19

135

Cs-AMSIn recent years, development of a highly sensitive detection method for a long-half-life cesium-135 (Cs-135: half-life of 2.3 million years) has been required as one of the anthropogenic nuclides of the nuclear age.
However, the Cs sputter negative ion source limits the analysis of cesium isotopes in AMS using a tandem
accelerator. For this reason, we have started development of the rubidium (Rb) sputtering negative ion
source by replacing Cs of the S-5 ion source (MCG-SNICS) with Rb. At present, the maximum 133Cs19F2−
beam current of 0.2 μA was obtained from Cs2SO4 mixed with PbF2. 133Cs19F2− was accelerated with aterminal voltage of 6 MV as a beam transport test. A beam transmission of 133Cs9+ with an energy of 58.7
MeV was about 1.3%.
Measurement history

Number of AMS measuring samples

1200
Be-10

C-14

Al-26

Cl-36

Ca-41

Sr-90

I-129

1000
484

800
88

600
400
200
0

294

143
184
30
321

119
29

257
29

23

165
196
187

322
180

13
FY 2016

FY 2017

FY 2019

42

29

85

FY 2018427

377

FY 2020

FY 2021

Fiscal year
Fig. 2. Cumulative number of measured samples for AMS since 2016.

Figure 2 shows the cumulative number of measured samples since the AMS system started operation. A
total of 4,037 samples was measured from 2016 to 2021.
References[1] K. Kanzawa et al., JGR Space Physics 126 (2021) e2021JA029378.
[2] K. Sasa et al., UTTAC Annual Report 2019, UTTAC-89 (2020) 10.

20

3.2

Reconstruction of 129I input history to the surface environment using acore from Beppu Bay

Z. Shi, A. Sakaguchi, K. Sasa, M. Matsumura, T. Takahashi, S. Yamasaki, K. Sueki
The Earth's environment has drastically changed by human activities in the past several decades. To
describe this human age, scientists have proposed the setting of a new geological time scale, theAnthropocene. To define this new geological age, some candidate places for setting the Global Boundary
Stratotype Section and Point (GSSP) have been raised and discussed in the international committee. Amongthe many identified candidate areas, Beppu Bay, Japan, is considered a very favourable candidate.
In this research, we focused on iodine-129 (129I, T1/2 = 15.7 Ma) which is the long-lived radioiodine.
Anthropogenic 129I is known to have been released to the environment by human nuclear activities such as
nuclear bomb testing, nuclear fuel reprocessing, and nuclear accidents. Some of the previous researchclarified 129I input history to the surface environment using coral cores [1] and sediments of brackish lakeand estuary [2, 3], thereby evidenced specific human nuclear activity. Thus, it is expected that 129I becomes
an important marker for the Anthropocene as a fingerprint of human activity if the reconstruction of the
input history of 129I can be achieved with the Beppu sediment samples. Eventually, the results obtained here
will serve as an aid to set Beppu Bay as GSSP for the Anthropocene.
A sediment core sample (BMC19 S1-3) was collected from Beppu Bay (33°16'40.6"N, 131°32'35.2"E;
70.7m water depth), and cut into 1 cm segments from the sediment surface to 90cm depth. The sedimentation
rate of this sediments was determined by caesium-137 (137Cs) and lead-210 (210Pb) methods [4]. Twoprocedures were conducted to determine the bulk stable iodine concentrations in each sediment layer. One
is the TMAH (tetramethyl ammonium hydroxide) leaching method: the sediments were leached with 25%
TMAH solution at 80℃ for 12 hours. The other is the pyrohydrolytic procedure method: the sediments were
calcinated at 990℃ and the iodine released from sediments were trapped by mixed solution of 1% Na2SO3
and 1%TMAH. The concentrations of 127I in leaching/trapping solutions were measured with Inductively
Coupled Plasma Mass Spectrometer (ICP-MS, Agilent 7700) with 185Re as an internal standard solution.
For analysis of 129I/127I, iodine was collected by the pyrohydrolytic procedure, and was chemicallypurified by solvent extraction and backextraction methods.

Finally, iodine wascollected as AgI precipitates by adding AgNO3
solution to an aqueous solution. Dried AgI was
mixed with Nb (AgI:Nb=1:4 in mass ratio),which is an ionization supporter for iodine,and measured 129I/127I ratios with Accelerator
Mass Spectrometry (AMS) at UTTAC. By
comparison between the concentrations of 127I
obtained by the two methods (TMAH leachingand pyrohydrolytic procedure), the higher

Fig. 1. Concentration of 127I in sediments from Beppu Bay
in the period 1944−1995.

21

concentrations of 127I were employed as the bulk concentration of stable iodine (Fig. 1) considering the
cumbersome method and complex composition of marine sediments with contributions of organic and inorganic
iodine precipitations. The concentration of 127I lies in the range of 40-75 ppm with an average of 59.2 ppm,
which is in line with the general range of iodine concentration in the oceanic sediment.127I concentrations
are uniform around 1948-1967, and then decrease in 1970 sharply. The 127I concentrations fluctuate more
after 1970, but any significant trend could not be seen over years.
Atom ratios of 129I/127I in sediments fromBeppu Bay vary from 5.07×10−13 to
1.11×10−10 over analysis years (Fig. 2). The
atom ratio of 129I/127I increases from 1944 to1948 but decreases slightly around 1953.
The ratio gradually increases with prominent
peaks at 1958, 1969 and 1975. Then the ratio
slightly decreases and keep higher values in
1980s and 1990s compared with those before
1970. The rough trend of 129I/127I ratios
through the 1940s to the present, i.e.,

Fig. 2. Atom ratio of 129I/127I in Beppu Bay sedimentsin the period 1944−1995.

gradual increase of the ratio over the years,
is similar to those of marine sediments from Jiaozhou Bay, China [5] and the coral core sample from theJapan Sea [1]. However, significant signals such as the maximum nuclear testing, hydrogen bombing,Chernobyl accident were not clearly found in the core from Beppu Bay. These are due to the complex
composition of the sediments and the unclear sedimentation process of iodine in the Beppu Bay system.
The variation of iodine isotopes might reflect the human nuclear activity somehow, although the records
are not so clear as the result from coral samples. Thus, when the iodine isotope composition is used as amarker for the Anthropocene definition, the behaviours of both terrigenous and authigenic iodine following
the surrounding environmental changes must be well considered.

References[1] A. Sakaguchi et al., Mar. Environ. Res. 142 (2018) 91.
[2] Y. Ishiga et al., Geoscience Rept. Shimane Univ. 36 (2018) 39.
[3] Y. Satoh et al., J. Radioanal. Nucl. Chem. 322 (2019) 2019.
[4] S. Takahashi et al., Sci. Total Environ. 743 (2020) 140767.
[5] Y. Fan et al., J. Environ. Radioactiv. 154 (2016) 15.

22

3.3

Development of a measurement technique for 135Cs as a new oceanic
circulation tracer

D. Shiine, A. Sakaguchi, K. Sasa, T. Takahashi, M. Matsumura, S. Yamasaki, K. Sueki
Cesium-135 (135Cs, T1/2=1.33 million years) is an important nuclide that requires monitoring in wasterelated samples and environmental impact assessment because of its long-term persistence in radioactive
waste. On the other hand, it is expected to have a potential as a geochemical tool/tracer for seawater
circulation, which can identify the origin of water masses, and for other geoscientific applications byutilizing it together with short-lived 137Cs. However, there are some problems especially in the analysis ofultra-trace amounts of 135Cs in seawater by mass spectrometry, (1) the measurement of 135Cs using
accelerator mass spectrometry, which is considered to be the most promising method for the ultra-trace
measurement, is limited because of severe interference by isobar 135Ba in addition to use 133Cs as a sputter
ion source, (2) a large amount of 133Cs carrier , which will interfere with mass spectrometry, should be added
to seawater when the conventional Cs concentration method ‘ammonium phosphomolybdate coprecipitation(AMP)’ is employed [1], and this AMP is in powder form making it difficult to handle particularly on board,and (3) AMS analysis requires that the analyte should be extracted as a negative ion beam from solid samples,but Cs compounds that can extract Cs as a negative ion are unknown, since Cs tends to be a positive ion. In
order to solve these problems, the following studies were conducted to measure Cs isotopes by AMS andthe concentration of Cs from seawater.
Rubidium (Rb), which has similar physicochemical properties to Cs, was used as a sputter ion to replaceCs, and a new Rb ion source was established. By sputtering some kinds of Cs reagents with Rb, weinvestigated whether Cs in the sample can be extracted by Rb ions. Actually, we examined the speciation of
the negative ion beam of Cs extracted from the sample. In the experiments, Cs2SO4, CsNO3, Cs2CO3, CsBr,
CsI and mixtures of PbF2 with these Cs reagents were used to extract Cs as a fluoride beam [2]. Further, thecurrent intensity of the Cs beam was increased by optimizing the oven temperature and the ionizer in the Rb
ion source. By introducing the beam into the final ionization chamber, signals of nuclides with a mass
number of 135 were measured.
The adsorption rates of 137Cs and 133Ba added
to seawater were investigated using copper(hereafter referred to as "PB") by a batch
method. After the adsorption experiments, thePBs were leached with several concentrations ofhydrochloric acid and nitric acid to find theCurrent value(nA)

substituted Prussian blue non-woven fabric [3]Cs₂SO₄10

optimum conditions for Cs desorption from the

0

PB.

130

Cs₂CO₃150 160 170 180 190
Mass number
Fig. 1. Mass spectra of ion beams extracted from
Cs2SO4+PbF2 and Cs2CO3+PbF2.

Current intensities more than 10 nA were

23

140

found for CsO2− and CsF2− beams from Cs2SO4
and Cs2CO3 mixed with PbF2 sputtered by Rb (Fig.
1). Considering the preparation and stability of thesample, Cs2SO4+PbF2 is expected to be used as an
AMS sample in the future. In addition, an
accelerated beam of CsF2− obtained fromCs

Cs2SO4+PbF2 allows extraction of multiplyBa

charged Cs ions. Thus, it can be concluded that the
Rb ion source actually succeeded in extracting Csfrom the sample. The spectrum with a mass
number 135 was also confirmed by the final
detector after optimizing the oven temperature andionizer current value (Fig. 2).
The Cs adsorption rates with 0.92-46.0 µmol

Fig. 2. 2D spectrum showing the unresolved peak of135
Cs9+ and 135Ba9+.

of PB for 1 kg of seawater were 20.2-95.8% (Fig.
seawater is required to efficiently adsorb Cs. On
the other hand, the adsorption rates of Ba, which
is an interference element in mass spectrometry,
was less than 5.3% for all sizes of adsorbents,

Adsorption rate [%]3). Therefore, about 46 µmol of PB per 1 kg of100

indicating that it is relatively difficult to adsorb Ba

86.6

92.9

95.8

80
60
40
20

20.2
3.5

2.9

5.3

23

46

0
0.9

on the PB. In the desorption experiment, 97.2 ±11.5

PB amount of substance [μmol]

2.6% of Cs desorption was found in 35% HCl.

Fig. 3. Cs and Ba adsorption rates on PB.

References[1] M. Aoyama et al., Appl. Radiat. Iso. 53 (2000) 159.
[2] J. Eliades et al., Nucl. Instr. Meth. Meth. Phys. B 294 (2018) 361.
[3] T. Yasutaka et al., J. Nucl. Sci. Tech. 53 (2016) 1243.

24

3.4

The performance of iodine-129 AMS measurements at the University ofTsukuba (FY 2021).

M. Matsumura, K. Sasa, T. Takahashi, A. Sakaguchi, T. Matsunaka1, K. Sueki
Continuing from 2017, we have reported that the performance of 129I measurements by accelerator mass
spectrometry (AMS) for the development of the standard reference materials (STD) of 129I in the near future.
Details of the 129I AMS measurements are described in the references [1-2].
From April 2021 to March 2022, we measured 427 samples of 129I, the details of which are shown in
Fig. 1. The test samples were chosen from natural environment such as sea, rain, river water, and sediments.
Figure 2 shows the measured values of carrier-reagent blanks. The machine background is estimated to beon the order of 10−15 in the 129I/127I ratio, which is sufficiently lower than the background level of the ratioof 2 × 10−14 for ”Old Iodine” provided from Deep Water company, USA. However, sometimes, the measured
129 127

I/ I values in blanks ranged over ten times higher than 2 × 10−14. One of the causes for this might be thememory effect. The rise in blank values in 2018 and 2019 is most likely caused by this memory effect,
however, the memory effect has been prevented by measurement schemes since 2020.

Measured 129I/127I (×10-14)

129I/127I [×10-14]

100
10
2×10-1410
0

20

Fig. 1. Details of measured 129I
by the AMS system in fiscal 2021.

40
60
80
Run Number (2016/4-2022/3)

100

120

Fig. 2. 129I/127I ratios in blanks.
We have measured the certified materials since 2020. The results of measurement for Standard Reference

Material® 3230, Level Ⅰ and Level Ⅱ, provided from the National Institute of Standards and Technology(NIST, USA) are shown in Fig. 3. They were normalized by using Purdue-2 STD (Z94-0596) with an 129I/127I
ratio of 6.54 × 10−11 [3] (the value was revised in 2014 [4]), which was provided by the Purdue Rare Isotope
Measurement Laboratory (PRIME Lab) at Purdue University, USA. The nominal 129I/127I ratios are (4.920± 0.062) × 10−10 and (0.985 ± 0.012) × 10−12, for NIST 3230- Level Ⅰ and Level Ⅱ, respectively. The two
samples after sputter-cleaning for 1 or 5 min. were measured in each run. The measured values of Level Ⅰ areapproximately 10% lower than the nominal one. The resulting ratio and standard deviation (1σ) of the

precision are (4.362 ± 0.048) × 10−10 (1.1%) and (0.918 ± 0.070) × 10−12 (7.6%), respectively.
This work was supported in part by JSPS KAKENHI Grant Numbers 20H01173 and 21H04336.

1

Kanazawa University

25

NIST_3230_Ⅰ ((4.920 ±0.062)×10-10) normalized by Purdue2(65.40)
540
520

129I/127I [×10-12]

500
480
460
440
420
400
0

20

40

60

80

100

20

40

60

80

100

-12) normalized by Purdue2(65.40)
NIST_3230_Ⅱ ((0.985 ±0.012)×10
run number

1.5
1.4
1.3

129I/127I [×10-12]

1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0

run number

Fig. 3. Measured 129I/127I ratios of NIST 3230-STD. The error bars attached to all measured points
represent counting statistics. The dots of the same color correspond to the same target.

References[1] K. Sasa et al., Nucl. Instrum. Meth. Phys. Res. B 437 (2018) 98.
[2] M. Matsumura et al., UTTAC Annual Report 2019, UTTAC-89 (2020) 16.
[3] P. Sharma et al., Nucl. Instrum. Meth. Phys. Res. B 123 (1997) 347.
[4] M. Caffee, (Purdue University), Private communication (2014).

26

Vertical distribution and temporal changes of 129I in soil derived from the
Fukushima Daiichi Nuclear Power Plant accident

3.5

Y. Gao, A. Sakaguchi, K. Sasa, M. Matsumura, T. Takahashi, Y. Ota, K. Sueki
Studies related to the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident reported depth
profiles of 129I at upland field, empty lot, and ground level in Fukushima [1]. Also, the workers reported
observations of changes in depth distribution of one sampling point for less than a year [2].
To clarify the long-term migration behavior of 129I, depth profiles of 129I in soil at the same site in thevicinity of FDNPP have been evaluated over a long period of time from 2 to 10 years after the accident. Fromthe measured depth profiles of 129I in the soil, (i) the downward mobility of 129I derived from FDNPP was
estimated, and (ii) the behavior of 129I in the soil were analyzed using a diffusion model. Further, we
attempted to predict the amount of 129I in the soil in the next 100 years by using a diffusion model. Cs-137
in the same soil samples was also analyzed to compare the differences in the migration processes of theseelements.
About 30-cm-long soil cores were collected from Namie-machi, Fukushima on June 12, 2013, June 17,
2016, September 10, 2017 and November 6, 2020. These samples were cut into 1−4 cm segments from thesurface of the core. Each sample was freeze-dried and homogenized [3].
Iodine in soil was extracted by the pyrohydrolysis method, and was purified by solvent extraction/backextraction method. Finally, the iodine was precipitated as AgI for AMS [4]. The 129I/127I ratio was measured
by the AMS system at UTTAC. The 127I concentration in the trapped solvent obtained by pyrohydrolysis
was measured with the Inductively Coupled Plasma-Mass Spectrometer (ICP-MS, Agilent 8800). The
amounts of 129I in the soil cores were calculated using 127I concentrations obtained from ICP-MS and 129I/127I
ratios obtained from AMS.
The depth profiles of 129I obtained over the years show that the concentrations of 129I derived from the
FDNPP decrease with increasing depth from the surface [5]. More than 80% of the 129I inventory is
accumulated in surface layers (less than 2.5 g/cm2 in mass depth). Thus most of the accident-derived 129I isaccumulated in the surface soils. By applying the one-dimensional (1D) diffusion model from the ICRU
report, the expectation mass depth α (g/cm2), which represents the migration of 129I and 137Cs during theobservation period, is calculated. The results are shown in Table 1 and also in Fig. 1.
Table 1. Expectation mass depths (g/cm2) of 129I and 137Cs during the observation period.
Date of soil corecollection

Expectation mass depth of 137Cs

Expectation mass depth of 129I

（g/cm2）（g/cm2）

2013/6/12

0.88

0.91

2016/6/17

0.77

1.19

2017/9/10

1.27

1.74

2020/11/6

1.23

1.40

27

Fig. 1. Expectation mass depth of 129I and 137Cs over the years since the FDNPP
accident, determined by applying the 1D diffusion model.

From Fig. 1, the downward migration rates of accident-derived 129I and 137Cs were determined to be 0.07
g/cm2/yr and 0.06 g/cm2/yr, respectively. There appears to be a difference between the two in the expectation
mass depths, but not in the downward migration rates. It may be predicted from the present results that the
expectation mass depth of FDNPP accident-derived 129I in 100 years would be about 8 g/cm2 (about 8 ~ 9
cm depth), indicating that 129I may continue to remain relatively in the surface layer.

References[1] M. Honda et al., Applied Geochem. 85 (2017) 169.
[2] M. Honda et al., J. Environ. Radioact. 146 (2015) 35.
[3] Y. Ota et al., UTTAC Annual Report 2018, UTTAC-88 (2019) 21.
[4] Y. Muramatsu et al., Quat. Geochronol. 3 (2008) 291.
[5] Y. Gao et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 24.

28

3.6

Surface distribution of iodine-129 in the Arctic Ocean

T. Matsunaka1, S. Nagao1, M. Inoue1, Y. Kumamoto2, T. Takahashi, M. Matsumura, K. Sueki, K. Sasa
Over the last several decades, Arctic river discharge from several countries increased, conveying heatand freshwater into the Arctic Ocean, and resulting in the decline of Arctic sea ice [1]. The investigation ofwater dynamics change in the Arctic Ocean caused by the recent global warming is essential for forecasting
the response of ocean circulation with climate change. Anthropogenic 129I (T1/2 = 15.7 million years)
produced from the thermal neutron fission, is dominated by release from nuclear fuel reprocessing plants inthe Europe and is supplied at the Arctic Ocean via atmospheric deposition, surface runoff, and sea currents.
To illuminate the availability of 129I as a tracer of surface circulation in the Arctic Ocean, we investigatedthe horizontal distribution of 129I in 2019.
The dissolved 129I in surface water in the Arctic Ocean, Bering Sea, and North Pacific Ocean varies from13.6±0.9 to 250±4.2 nBq L–1, and is negatively correlated with water temperature (Fig. 1A, R2 = 0.74) andsalinity (Fig. 1B, R2 = 0.85). This water temperature and salinity-dependent distributions reveal that the
dissolved 129I in the Arctic Ocean is controlled by mixing of water mass from the Arctic Ocean surface mixed
layer water with cold and lower salinity and the Alaskan Coastal Water from Bering Sea with warm andhigher salinity. 129I is considered to be a tracer for the front of the Arctic Ocean surface mixed layer water
influenced by the freshwater input.

B

A

Fig. 1. The correlations between 129I activities in surface seawater and (A) water temperature, and (B) salinity
in the Arctic Ocean, Bering Sea, and North Pacific Ocean in 2019. The linear regression lines and coefficientsof determination (R2) are shown in the correlation diagrams.

Reference[1] H. Park et al., Science Advances 6 (2020) 4699.

1
2

Kanazawa University
JAMSTEC

29

4.
ION-BEAM APPLICATIONS

From the backyard of UTTAC

An engineer making experimental items using a grinder

4.1

Composition analysis of particles released from the FDNPP using
microbeam scanning PIXE

K. Sueki, T. Nakamura, S. Ishii, K. Sasa, S. Tomita
Among the radioactive substances released from the Fukushima Daiichi Nuclear Power Plant (FDNPP)
in the March 2011 accident, the particulate matter called radioactive particle that is highly contaminatedwith radioactive cesium has been found [1]. We have reported on the composition of radioactive particles
that have been found so far by quantitative analysis of the main components and by elemental mapping ofsilica glass particles. The main components of the sample T47 whose surface was polished were analyzed
by PIXE using a microbeam of 2 MeV protons and a Si(Li) detector, from which we were able to detect Srthat could not be observed by SEM-EDS analysis until now [2]. The scanning analysis with a 4 MeV proton
microbeam from the 6MV tandem accelerator was carried out using a CdTe detector, thereby the authors
succeeded in obtaining elemental mapping of Sr and Pb [3].
In the present work, we compared the information obtained by elemental mapping of non-processedradioactive particles with that obtained by detectors of different type and by SEM/EDS. We also measured
not only the particles of silica glass, but also the particles mainly composed of iron oxide, and also theparticles in which iron oxide and siliceous glass are mixed, similar to the measured radioactive particles.
The data collected with two types of detectors, a CdTe detector and a silicon drift detector (SDD) were used.
The data obtained by SDD can be compared with SEM-EDS. The beam current was maintained at several
pA for a beam size of 8 μm square in consideration of sufficient X-ray intensity. It was possible to collimate
the beam size to 1-2 μm square, but at that time the intensity was much lower than 1 pA and practicalmeasurement was not possible. The measured four samples, T47, R008, Y04, and Y06, which were takenout of the environments except for T47 and were not processed at all.
Figure 1 shows the X-ray spectra measured for the narrow (for T47, R008, Y04, and Y06) and wide (forT47, R008, and Y06) energy ranges using SDD and the CdTe detector, respectively. The spectra for R008
and T47 are very similar, but the intensity of K X-ray from Ba at ~34 keV is obviously higher for R008 thanfor T47. In this case, the X-ray yield was not enough to take an elemental map. It was found from SEM/EDS
observation that Y06 was in such a situation where siliceous glass was attached to a piece of iron oxide and,as a result, Si, Fe and Zn were strongly observed in the spectrum, while Pb, Sr and other heavy elements
were not observed. Y04 is also considered to be an oxide of iron, but the composition is different from thatof Y06 since both Fe and Si are observed in the whole particle.
Figure 2 shows a comparison of the elemental maps for Y06 by PIXE with those by SEM/EDS. It isnoticeable that Fe is observed with a considerable intensity in the map-i even where Si is rich, whereas it ishardly visible in the map-b. This is because 4 MeV protons reach a depth of several tens of µm from thesurface, while SEM/EDS can only observe X-rays from the surface layer of 1 µm thickness or less.
Observing particles with complicated shapes without processing causes problems in quantification, but
the present work has shown a possibility that new findings can be obtained by using them so as tocomplement SEM/EDS in element mapping.

30

Fig. 1. PIXE spectra of radioactive particles measured with (a) the silicon drift detector and (b)the CdTe detector.

Fig. 2. SEM images and elemental maps of the radioactive particle Y06. a: SEM image, b–e:
SEM/EDS elemental maps, f: backscattered electron image and g–j: PIXE elemental maps. Maps b
and g for Si, c and h for Ca, d and i for Fe, e and j for Zn. The map-g was measured by SDD and h– jwere observed by the CdTe detector.

References[1] Y. Satou et al., Geochem. J. 52 (2018) 137.
[2] M. Kurosawa et al., UTTAC Annual Report 2018, UTTAC-88 (2019) 31.
[3] K. Sueki et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 28.

31

4.2

Determination of H concentration in solids by T-ERDA

H. Kudo, M. Kurosawa, H. Naramoto, M. Sataka, S. Ishii, K. Sasa, S. Tomita
It is of practical interest to establish transmission ERDA (T-ERDA) as a standard technique ofquantitative hydrogen analysis, considering open use of this technique in future at UTTAC not only byinternal, but also by external users.

For this purpose, we have carried out T-ERDA using well-characterized

samples of polyphenylene sulfide (PPS) and natural muscovite [1]. Figure 1 shows the experimental setup
which has been optimized for the quantitative H analysis, compared with the previous cases [2, 3].

Fig. 1. Schematic diagram of the experimental setup for T-ERDA.

The PPS samples are stacked layers of 1.35-μm thick PPS and Al foils, which were used in the previous
work [3]. The muscovite sample of ~12 μm thickness was prepared by cleaving the bulk muscovite which
was collected from a granitic pegmatite rock at Ishikawa, Fukushima Prefecture. These samples were fixed
on the Al foil of 50 μm thickness to prevent the incident He from entering the particle detector. Figures 2
and 3 show energy spectra of recoil H measured with SSD in Fig. 1.

Fig. 2. T-ERDA spectra for incidence of 8 and 9
MeV He2+ on the three PPS samples, shown for thesame number of incident He2+, 2×1011.

Fig. 3. T-ERDA spectra of recoil H from themuscovite sample, shown for the same number
1.05×1012 of incident 8 and 9 MeV He2+.

According to the previous study [3], the present T-ERDA can be discussed using the straight-path
approximation for the trajectories of He and recoil H. It is notable that the angular spread of recoil H after
passing through the present sample causes negligible change in the H yield. This is because the differential
recoil cross section changes slowly with recoil angle in the narrow forward direction under consideration,
hence the H yield is unchanged as a whole even when the recoil directions of recoil H are smeared and32

mixed with each other by the multiple scattering suffered in the sample. Such physical backgrounds simplify
the analysis of the experimental data.
The analysis of the H spectra shown in Figs. 2 and 3 has been based only on the database of stopping
power and recoil cross section for material analysis [4], without using any reference sample of known H
content. For PPS, the determined H concentration is (2.87±0.26)×1022 H/cm3. This value agrees well andconsistently with the calculated concentration of 3.01×1022 H/cm3 from the nominal density of 1.35 g/cm3
and the atomic composition of (C6H4S)n, using Avogadro's constant, which demonstrates the validity of thepresent analysis. For the muscovite sample, the determined H concentration as a function of the depth isshown in Fig. 4. We see that the results for 8 and 9 MeV He agree consistently with each other at the depth
from 1.5 to 11 μm. Outside this depth range, the slopes near the high- and low-energy ends of the spectra
should lead to unreliable results. We see uniformity of the H concentration at a depth of 1.5-11 μm, hence
the average value (9.43±0.75)×1021 H/cm3 is obtained. This value agrees excellently with the concentrationof 9.36×1021 H/cm3 obtained from the composition data, using the density of the muscovite 2.83 g/cm3 andAvogadro's constant. The results also imply that the H concentration originating from absorbed water isuniform in the muscovite, like that from bound water constituting the crystal structure of muscovite.

Fig. 4. H concentration in the muscovite, determined by T-ERDA. The uncertainty of ±8% in thevalues is shown for the 8 MeV case. The horizontal gray thick lines indicate the calculated values of
9.36×1021 H/cm3 (upper) and 8.61×1021 H/cm3 (lower), with and without the absorbed water in the
muscovite sample, respectively. The width of these lines represent the uncertainty in the calculation.

For both PPS and the muscovite sample, the determined hydrogen concentrations are in good agreementwith the calculated ones. The present quantitative H analysis demonstrates the capability of accurate
determination of H contents in materials and minerals by T-ERDA.
References[1] H. Kudo et al., 2022 J. Phys.: Condens. Matter https://doi.org/10.1088/1361-648X/ac8b4e, also
uploaded at arXiv:2206.02387.
[2] A. Yamazaki et al., AIP Advances 9 (2019) 105111.
[3] H. Kudo et al., J. Phys.: Condens. Matter 33 (2021) 465901.
[4] IBANDL (Ion Beam Analysis Nuclear Data Library). https://www-nds.iaea.org/exfor/ibandl.htm

33

4.3

Effect of LiCoO2 positive electrode insertion in all-solid-state Li-ion
batteries investigated by NRA

N. Kishi, S. Kobayashi1, Y. Sugisawa, R. Shimizu1, T. Hitosugi1, D. Sekiba
All-solid-state Li-ion batteries are attracting much attention, which would safely increase the capacityof Li-ion batteries. At present, there remains a problem that the conductivity is not sufficient for practicaluse. In the previous study, we tried NRA using the nuclear reaction 7Li (p, α) 4He to obtain the Li depth
distribution under the operando conditions of an all-solid-state Li-ion battery in order to reveal the Li
behavior at interfaces [1]. To check the feasibility of NRA at that time, we used a simplified battery in whicha single Au layer (t=100 nm) was used for positive electrode and collector. As a result, we confirmed that
non-destructive NRA has a sufficient depth resolution and can be used for operando measurement of allsolid-state Li-ion batteries. Recently, we have obtained NRA results for a more practical sample than before,
which has a positive electrode layer made of LiCoO2 (t=300 nm). The comparative analysis between thesimplified and practical batteries is presented in this report.
NRA was performed using 1MV Tandetron at UTTAC.
Figure 1 (a) shows the schematics of the experimental(a)arrangement. We used a 1.5 MeV H+ beam. The detector
was mounted in the direction of 150° with respect to thebeam direction, and the sample was tilted so that thedrection of the detector was 70° from the surface normal.
Figure 1 (b) shows the schematics of the practical sample.
The sample consists of stacked layers of Li/Li3PO4/
LiCoO2/Au deposited on a Si3N4 substrate of 1 µm
thickness. In order to perform the operando measurement,(b)a positive voltage is applied to the Au layer (collector) withrespect to the Li layer (the negative electrode). The power
supply for the bias voltage and the ammeter wereconnected to the sample in vacuum through a feedthrough.
The sample was discharged at the bias voltage below 3.0 V
and charged at the bias voltage above 4.3 V. Thus the
behavior of 7Li was studied by comparing the NRA spectraat the bias voltage of 4.3 V and 3.0 V.
Figure 2 (a) shows the NRA spectra measured for the

Fig. 1. Schematics of (a) the experimental
arrangement and (b) the sample.

simple battery (previous data) [1]. The measurement
conditions were similar to those for the practical sample
except the applied voltages, 5.0 V and 0.1 V for charge and discharge, respectively. The NRA profiles

1Tokyo Institute of Technology.

34

corresponding to the first charge, discharge, and the second charge are represented by blue, orange, andgreen lines, respectively. Comparing the blue and orange lines, we notice that the Li ions penetrate into the
Au layer, and form the Au-Li alloy layer around 3270 ~ 3320 channel. This implies a self-organization of
the positive electrode. On the other hand, the relative yield of Li layer (negative electrode) around 3050
channel decreases to compensate the Au-Li alloy formation. Figure 2 (b) shows the NRA spectra measured
for the practical sample. The applied voltages of +4.3 V, +3.0 V, and again +4.3 V to the Au layer, arerepresented by blue, orange, and green lines, respectively. In contrast to the case of the simplified sample,
we cannot find any drastic change in the NRA spectra through the measurements, while there are subtle
changes at both the positive and negative electrodes. We may conclude that this practical battery is of stablestructure during the charging and discharging cycle.
In order to focus our attention into the slight changes found in the practical battery, we will improve thestatistical accuracy as future work by, for example, increasing the number of detectors and using higherenergy protons, which has larger NRA cross sections. Furthermore, it would be interesting to use a 6Lienriched target in the deposition of a particular layer.

(a)

(b)

Fig. 2. NRA spectra of (a) Li /Li3PO4 / Au/ Si3N4 and (b) Li /Li3PO4 / LiCoO2/Au/ Si3N4.

Reference[1] Y. Sugisawa et al., UTTAC Annual Report 2020, UTTAC-90 (2021) 26.

35

5.
ISOTOPE APPLICATIONS

From the backyard of UTTAC

Monitoring radioactivity for radiation management

5.1

Characterization of GaN grown by oxide vapor phase epitaxy by meansof positron annihilation spectroscopy

A. Uedono, J. Takino1, T. Sumi1, Y. Okayama1, M. Imanishi2, S. Ishibashi3, Y. Mori2
GaN-based vertical power devices have gained tremendous attention due to their potential for largecurrent and high-voltage operations [1]. Compared with Si and SiC-based devices, the advantages of the
GaN devices are a lower on-resistance and higher breakdown voltage, and their trade-off relationship is
close to the physical limit of GaN [2]. Although their promising properties are clear, one of the obstacles fortheir commercialization is a lack of high-quality, low-cost, and large-diameter GaN substrates. The halide
vapor phase epitaxy (HVPE) method is a well-established and commercialized method for growing bulk
GaN [3]. Although the advantage of HVPE is its high growth rate (> 100 μm/h), the long-term growth ofthe crystal is limited because of ash accumulation in reaction chambers. Recently, for long-term growth of
GaN without ash accumulation, oxide vapor phase epitaxy (OVPE) methods were developed [4]. In thepresent work, we use positron annihilation spectroscopy to probe vacancy-type defects in GaN grown by
the OVPE method [5].
The present samples were GaN grown by the OVPE method.
Details on the sample preparation process and the relationshipbetween their properties and growth conditions are given
elsewhere [4]. Impurity concentrations in the samples were
evaluated by secondary ion mass spectrometry (SIMS), and theresults are shown in Fig. 1. In the present work, the samples arereferred to as O1 to O6 according to their hydrogenconcentrations [H]. Details on the positron annihilation
technique used in the present work are given elsewhere [6]. The
Doppler broadening spectra of the annihilation radiation were
measured with Ge detectors as a function of the incident positronenergy E. The obtained spectra were characterized by the lineshape parameter S, defined as the fraction of annihilation events

Fig. 1. Impurity concentrations in
OVPE-GaN samples (O1−O6)
measured by SIMS.

over the energy range of 510.22–511.78 keV.
Figure 2 shows the S parameter of the typical OVPE-GaN samples (O1, O3, and O5) and the MOVPE(metal-organic vapor phase epitaxy)-GaN film grown on O1 (MOVPE/O1) as a function of incident positronenergy E. The increase in S at a low E is due to the annihilation of positrons at the surface of the sample.
For OVPE/O1, the S value was found to saturate at E > 15 keV, and this value was close to the S value for
defect-free GaN reported in previous works [7]. The solid curves in Fig. 1 are fits to the experimental data,
and the derived diffusion length of positrons Ld for MOVPE/O1 was 77±3 nm. The obtained value of Ld was1

Panasonic Corporation
Osaka University
3
CD-FMat, AIST
2

36

Fig. 3. (a) Relative transparency and (b) S
parameters measured by coincidence Doppler
broadening system [6] with E = 28.6 keV for
OVPE-GaN samples.

Fig. 2. Relationships between S parameters
and incident positron energy E for OVPEGaN (O1, O3, and O5) and MOVPE-GaN
grown on O1 (MOVPE/O1).

typical for defect-free GaN. The concentration of vacancy-type defects in MOVPE/O1, therefore, is under
the detection limit of positron annihilation. This suggests that the effect of vacancy-type defects in thesubstrate was negligible in the top epitaxial film. For the OVPE-GaN samples, the saturated S value waslarger than that for MOVPE/O1, and the values of Ld were shorter than Ld of MOVPE/O1 (20‒30 nm), which
can be attributed to the trapping of positrons by vacancy-type defects. The obtained short diffusion lengthof positrons suggests that almost all positrons were annihilated from the trapped state of vacancies in thesesamples.
Figure 3(a) shows the relative transparencies and the S value measured by the coincidence system for
the OVPE-GaN samples (O1‒O6), where the transparency of defect-free GaN grown by Na-flux method[8] was used as a reference. It can be seen that the sample with low transparency tended to show a large S
value, suggesting a strong correlation between the transparency and vacancy-type defects in the OVPE-GaN
samples. The present experiments suggest that the control of vacancy-type defects is a key to improve thecrystal quality of bulk GaN.
References[1] H. Amano et al., J. Phys. D: Appl. Phys. 51 (2018) 163001.
[2] T. Ueda, Jpn. J. Appl. Phys. 58 (2019) SC0804.
[3] K. Fujito et al., J. Cryst. Growth 311 (2009) 3011.
[4] A. Kitamoto et al., Jpn. J. Appl. Phys. 58 (2019) SC1021.
[5] A. Uedono et al., J. Cryst. Growth 570 (2021) 126219.
[6] R. Krause-Rehberg and H. S. Leipner, Positron Annihilation in Semiconductors, Solid-State Sciences(Springer-Verlag, Berlin, 1999) vol. 127.
[7] A. Uedono et al., Phys. Stat. Sol. (B) 255 (2018) 1700521.
[8] A. Uedono et al., J. Cryst. Growth 475 (2017) 261.

37

5.2

Low temperature Mössbauer study on a hexagonal FeCo nitride

C. Kodaka, M. Kishimoto, T. Sekido, E. Kita, H. Yanagihara
Fe nitrides have been studied as magnetic materials consisting of common elements such as Fe andnitrogen. Fe nitrogen system forms metallic compounds with several crystal structures depending on thenitrogen content [1]. Small number of nitrogen atoms stabilizes an fcc-structure Fe which is a hightemperature phase of Fe and is never realized at room temperature. The Fe-N compound with the lowest
concentration of nitrogen is Fe16N2 with a body-centered tetragonal structure, which was extensively studied
as an expecting material with high magnetization exceeding bcc Fe [2] and high magnetic anisotropy [3, 4].
Higher nitrogen concentration compounds than Fe16N2 are Fe4N and Fe2-3N whose basic crystal structures
are fcc and hcp, respectively. Additionally, FeNi nitrides, (FeNi)N, has been studied as a precursor of L10FeNi ordered compound [3, 4]. On the other hand, nitrides of FeCo alloys have not been studied because ofdifficulty in their synthesis. Recently, the (FeCo)2-3N alloy with an hcp structure has been studied as novel
magnetic materials and/or starting materials for them by using the high-rate ammonia gas nitriding [5]. To
investigate magnetic property of (FeCo)2-3N, Mössbauer spectroscopy was performed at various
temperatures.
A sample was fabricated by nitriding of FeCo alloy
powder using the high-rate ammonia gas furnace. At first,
FeCo fine hydroxide particles were produced with a coprecipitation technique using Fe and Co chlorides. A
nominal atomic ratio of Fe and Co was set to 1:1. After
heating in an H2 gas atmosphere, FeCo spherical particles
with averaged diameters of about 400 nm were produced.
The FeCo particles were treated in the ammonium-gas
furnace to obtain the nitride. The structure of the productwas examined with XRD and was confirmed to be an hcp
single phase (see Fig. 1) and the nitrogen concentration
was determined with an inorganic elemental analysis at
Chemical Analysis Division, University of Tsukuba. A

Fig. 1. XRD pattern of (FeCo)2.48N fineparticles.

sample of (FeCo)2.48N was used for the measurement.
Mössbauer spectroscopy was performed at sample temperatures between room temperature and 2.6 K.

To obtain low sample temperatures, a closed-cycle refrigerator cryostat was used [6]. Velocity modulation
between −12 mm/s and 12 mm/s was applied to the 57Co gamma-ray source, and the number of transmitted
gamma rays were accumulated with a 512 channel MCS.
Figure 2 shows temperature dependence of Mössbauer spectra for the (FeCo)2.48N particles. Spectra
below 50 K depict combinations of magnetic sextets due to the circumstance of Fe atoms. The weak peaks

38

seen at 8 and −7.5 mm/s and are possibly

1.00

attributed to the Fe3+ oxide located on the

0.96

surface. As a reference, low temperature

0.92

Mössbauer spectra of Fe2.5N was analyzed

with hyperfine fields (Hhf) of 66, 142 and0.92

259 kOe [7]. Compared with Fe2.5N,

0.88
1.00

magnetic sub-spectrum with lower Hhf

0.96

should exist. This might be due to Co

0.92

atoms with low magnetic moment around

0.88
1.00

atoms

around

Fe

may

cause

the

distribution in Hhf.
With the increase of temperature, theRelative transmission

0.96

is small. Random arrangement of Co

1024ch0.88
1.00

by the combination of three sub-spectra

Fe atoms, of which transfer hyperfine field(FeCo)2.48N

RT

spectrum width becomes narrower and

0.96

512ch

100 K

90 K

0.92
0.88
1.00
0.98
0.96
0.94
0.92
0.90
1.00
0.98

almost constant above 100 K. This implies

110 K

75 K

50 K

0.96

that the magnetic transition temperature

0.94
0.92
1.00

(TC) places around 100 K. A tentative

0.98

magnetization measurement supports this

25 K

0.96

result. The TC for the (FeCo)2.48N is much

0.94

lower than that of the reference material,

1.00

Fe2.5N, reported to be 400 K [1].

0.98

Substitution of Fe atoms by Co atoms

0.96
0.94

should be responsible for the decrease in

2.6 K

-10

-5

0

5

10

Velocity (mm/s)

TC.

Fig. 2. Mössbauer spectra of (FeCo)2.48N particles at various
temperatures. Arrows indicate absorption peaks due to the Feoxides located on the particle surface.

References[1] M. Mekata et al., J. Phys. Soc. Jpn. 33 (1972) 62.
[2] J. M. D. Coey, J. Appl. Phys. 76 (1994) 6632.
[3] S. Goto et al., Sci. Reports 7 (2017) 13216.
[4] S. Goto et al., ACS Appl. NANO Mater. 2 (2019) 6909.
[5] Chihiro Kodaka, Bachelor thesis (in Japanese), Engineering science degree program, 2022 Feb.
University of Tsukuba.
[6] E. Kita et al., UTTAC Annual Report 2019, UTTAC-89 (2020) 34.
[7] G. M. Chen et al., J. Phys. Chem. 87 (1983) 5326.

39

5.3

57

Fe Mössbauer spectra of La/Fe-Al2O3

H. Asakura1, 2, K. Terasaka1
Even though electric vehicles have been attracting a lot of interest, internal combustion engine vehicles
will keep a strong presence in the coming decades. Oxygen storage material (OSM) is a key component fora kind of catalytic converters, three-way catalyst, which converts toxic exhaust gases such as CO,hydrocarbons, and NOx into CO2, N2, and water. To maximize the catalytic activity, CeO2-ZrO2 solid solution
has been used as only one practical OSM for co-catalyst of three-way catalysis to maintain oxygen
concentration to a suitable level. However, Ce and Zr
are relatively scarce and expensive. So, alternative
OSM have been desired.
We found, by chance, Fe-doped γ-Al2O3 works as
an OSM without any rare elements [1]. However, theFe-doped γ-Al2O3 (denoted as “Fe”) was decomposed
into α-Al2O3 under high temperature conditions, forexample, at 1273 K, which can be experienced under
the working condition of three-way catalysts.
Therefore, we prepared La/Fe-Al2O3 (“Fe-La”) from

Fig. 1. Thermogravimetric profiles of Fe, Fe-La,
Rh/Ce0.5Zr0.5O2 under oxygen storage/release cycles ofprecursors by an impregnation method, followed by 2% O2 and 2% H2 at 773 K.
calcination under air and reduction under diluted

γ-Al2O3 and aqueous solution of metal nitrates ashydrogen at high temperature. Rh/Ce0.5Zr0.5O2 was
prepared by a polymerized complex method, followedby an impregnation method.
The oxygen storage capacity (OSC) of thesamples was evaluated by thermogravimetic profiles
under cycle of 2% O2/He or 2% H2/He flow (Fig. 1).
The Fe and Fe-La exhibited comparable OSC (ca. 1.2wt%) to that of Rh/Ce0.5Zr0.5O2. The OSC of “Fe”
drastically decreased after the calcination at 1273 K(0.4 wt%), however, addition of La suppressed thisFig. 2. Thermogravimetric profiles of Fe and Fe-La,
calcined at 1273 K under oxygen storage/releaseWe performed XRD analysis on these samples andcycles of 2% O2 and 2% H2 at 773 K.
found that each sample except for Fe-La calcined atdeterioration and kept 0.9 wt% of OSC (Fig. 2).

1273 K exhibits simple XRD patterns assignable to the spinel structure. In addition, after the hightemperature reduction, the diffraction peaks shift to lower angles, corresponding to lattice expansion, which
1
2

Kyoto University
Kindai University (Current affiliation)40

indicate incorporation of Fe cations into the spinel framework of γ-Al2O3. Then, we tried Mössbauer
spectroscopy at room temperature to identify the states of Fe species.
Figure 3 shows the Mössbauer spectrum of Fe-La after
high temperature reduction. We obtained a reasonable curve
fitting result with two doublet peaks, which indicatespresence of Fe2+ and Fe3+ at the tetrahedral site of the spinelframework. In contrast, the spectrum of Fe-La in oxidized
state (Fig. 4) shows only one doublet peak with the same
isomer shift of Fe3+ at Td site after reduction. The small
amount of Fe3+ at the Td site in the reduced sample isexplained by the fact that it is easily oxidized in air underambient conditions. These results indicate that the Fe species
is incorporated into the Td site (A site) of the spinel structure.
On the other hand, the γ-Al2O3 framework of the Fe

Fig. 3. Mössbauer spectrum of Fe-La after
high temperature reduction.

sample without La doping completely collapsed into α-Al2O3
after the calcination at 1273 K as evidenced by their XRD
patterns. The Mössbauer spectrum differs from those of the
Fe-La samples and can be fitted with two doublet peaks, as
shown in Fig. 5. At present, we have assigned the two peaks
to Fe3+ at the Td site of the spinel structure and Fe3+ cations
incorporated into the α-Al2O3, thus the OSC of the Fe sample
after high temperature calcination significantly decreased.
Further analysis with in-situ XAS/XRD measurement isundergoing.
This work was performed under the management

Fig. 4. Mössbauer spectrum of Fe-La inoxidized state.

of “Elements Strategy Initiative for Catalysts &Batteries (ESICB)” supported by the Ministry of
Education Culture, Sports, Science and Technology(MEXT), Japan, program “Elements Strategy Initiative
to

Form

Core

ResearchCenter”(GrantNo.

JPMXP0112101003). A part of this work was
supported by JSPS KAKENHI “Grant-in-Aid for
Early-Career Scientists” (Grant No. 18K14055).
Fig. 5. Mössbauer spectrum of the Fe sample after
calcination at 1273 K.

Reference[1] K. Fujita et al., ACS Appl. Mater. Interfaces 13 (2021) 24615.

41

5.4

Mössbauer study of Fe ions in ferrocene derivative-based assemblies ona graphene oxide surface

M. Sakurai1, P. Koley1, E. Kita
Molecular assemblies of magnetic
molecules on a surface are attractive
building blocks in molecular spintronics
and electronics. Here, we study magnetic
properties of ferrocene derivative-based
assemblies formed through on-surface
chemical reactions (Fig. 1) by using 57FeMö ssbauer

spectroscopy

at

low

temperatures.
Fe ions in the ferrocene derivatives
on the graphene oxide (GO) nanosheet
have unpaired electrons through chargetransfer between the molecules and thenanosheet [1]. The isolated molecules areparamagnetic, however their assemblies
on the GO surface show hyperfine
splitting in Mö ssbauer spectra at low
temperatures. The present study showsthat onset temperature of the splitting is

Fig. 1. Transmission electron microscope (TEM) image offerrocene derivative-based assemblies (dark region) on agraphene oxide nanosheet.

higher for the assemblies with an average
diameter of 2.7 nm (Fig. 2) than those with an average diameter of 2.0 nm.
The splitting is caused by slow magnetization relaxation, because the reaction time of Mö ssbauer
spectroscopy with 10−8 – 10−12 s is shorter than the relaxation time of the molecular spins within theassemblies at low temperature. As the temperature decreases, the suppression of thermal spin fluctuations
produces spin correlations between the Fe ions, leading to the onset of slow magnetization relaxation. The
present approach based on assembling magnetic molecules in a self-organized manner and creating new
functionalities through the assembly provides new insights into molecular and low-dimensional magnetism.

1National Institute for Materials Science42T = 20 K

Relative transmission

T = 15 K

T = 12 K

T = 10 K

T=6K

T = 2.6 K
-10

-5

0

5

10

Velocity (mm/s)
Fig. 2. Mö ssbauer spectra of ferrocene derivative-based assemblies ona graphene oxide nanosheet at low temperatures.

Reference[1] M. Sakurai et al., J. Phys. Chem. 123 (2019) 29679.

43

6.
BEAM IRRADIATION EFFECT

Radiation tolerance test of electronic devices for use in space. The
JAXA team is acquiring the data remotely in the booth adjacent to theaccelerator operation desk. Recently, the experimenters are from
JAXA, industries, and our campus.

6.1

Evaluation of radiation resistance of MPU and LoRa communication
components for space applications

Y. Kurihara, H. Yoshikado, R. Tanaka, R. Takatsuki, T. Okamoto, T. Kameda
When using semiconductor components in space, it is necessary to consider the effects of cosmic
radiation for stable operation. In particular, heavy ions in cosmic radiation can cause SEE (Single Event
Effect), which can lead to temporary malfunctions (soft errors) and/or permanent failures (hard errors) insemiconductors and interfere with spacecraft operations, therefore detailed investigation is required inadvance.
We focused on space application of LoRa modulation because of its high interference tolerance oververy long distances and low current consumption. From this perspective, the feasibility of space applicationsof STM32L072CZ and the LoRa transceiver, SX1276 [1], built into the CMWX1ZZABZ-091 LoRa®
module [2] manufactured by Murata Manufacturing Co.
Using the 6MV tandem accelerator at UTTAC, we irradiated de-capped SRM32L072CZ and SX1276
with F and Cl ions with the condition shown in Table 1, while changing the number of ions, and monitored
the incidence of bit flips associated with soft errors and the increase in power consumption associated withhard errors to evaluate the SEU (Single Event Upset) and SEL (Single Event Latch-up) occurrence.
Two printed circuit boards of B-L072CZ-LRWAN LoRa®Discovery kit [3] were used as test
specimens, and Char type “U” (0x55, 0b01010101) was written in the unused 18KB area of the 20KB RAM
in STM32L072CZ for testing purpose. These boards were powered by a regulated power supply, and eachcurrent was recorded every 0.5 seconds using an INA216 (accuracy ±1%) to monitor SEL. The SEUs weremonitored by comparing all the data collected every 10000 ms during irradiation.
In Figure 1, 1A refers to SX1276 and 2B to STM32L072CZ. Table 1 summarizes the results ofexperiments. For STM32L072CZ, no SEU was observed during the test as the number of particles wasincreased. On the contrary, when SX1276 was irradiated, an increase in current of about 30mA was observedwith increasing a small amount of particles. Considering that roughly the same current of 30mA wasconsumed by SX1276 during transmission, we may assume that the SEU was generated and activated in aregister in the SX1276. Hence, the lower three bits of RegOpMode (0x01) may have changed from 000(Sleep mode) to 010 (FS mode TX) or 001 (Stdby mode) to 011 (Transmitter mode), although a further
investigation is required to prove such behavior.

In conclusion, STM32L0CZ MPU has resistance against2

cosmic radiation of LET=7.2 [MeV/(mg/cm )] level. SX1276 requires further investigation for quantitativeevaluation for space application.

44

Table. 1. Experimental results

Fig. 1. Specimens and irradiated positions.

References[1] Semtech Corporation, SX1276/77/78/79 Datasheet,https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/2R0000001Rbr/6EfVZUorrpoKFfvaF_Fkp
gp5kzjiNyiAbqcpqh9qSjE[2] Murata Manufacturing Co., Ltd., Type ABZ CMWX1ZZABZ, https://www.murata.com/jajp/products/connectivitymodule/lpwa/overview/lineup/type-abz[3] STMicroelectronics, B-L072Z-LRWAN1 Product overview, https://www.st.com/en/evaluationtools/b-l072z-lrwan1.html

45

6.2

Development of QCM sensor system for use in space

T. Shiobara1, E. Miyazaki1, H. Kukita2
As a result of contract development and joint research with Japan Aerospace Exploration Agency(JAXA), Nihon Dempa Kogyo Co., Ltd. (NDK) developed "New outgas analysis system: Twin-QCM sensor
system" for quantitative and qualitative analysis of outgas released from organic materials such as adhesives,
heat dissipation materials, and resins in a vacuum environment. This system was put on the market [1, 2].
JAXA and NDK have started a joint research for development of the flight model enabling the TwinQCM sensor system, which is mainly used now for research and evaluation on the ground, to be used inouter space on a satellite. In the flight model, we plan to use COTS (Commercial Off-The-Shelf) grade partsfor electronic parts to reduce the cost significantly and, accordingly, to evaluate the radiation resistance
performance of COTS grade parts in the space environment. A beam irradiation test using heavy ions fromthe 6MV tandem accelerator at UTTAC was performed for a BBM (bread board model) circuit board. Our
purposes are to conduct a test of the single event effect as a part of evaluation of the radiation resistance,
mentioned above, and to use the test result as a basis for determining whether or not to adopt the components.
(1) Experimental results in December 2021
Irradiation tests with 66 MeV Si10 + and 90 MeV Br14 + were performed. The test results and calculated
LET for Si10 + are described in the table below (the Br14 +data is omitted).

ManuParts
facturer

A

B

a

b

Component

Thickness
Material[μm]

Ionmass number

Energy [MeV]

Si

28

66.00

After passing thru. the substance
LET in Si[M eV/(mg/cm2)]

Test results

Initial−−Range in Si[μm]
12.40822.720

Scatterer

Au

0.20

12.53222.041 SEL: no occurrence

Wiring layer

Al

6.50

13.623

Semiconductor
sensitive layer

14.569 disturbance occurred

Si

1.00

13.73913.569 (#1)

Si substrateSi

106.00

0.000

0.000

Initial−−12.40822.720

Scatterer

Au

0.20

12.53222.041

Wiring layer

Al

4.70

13.348

Semiconductor
sensitive layer

16.641 SET: no occurrence

Si

1.00

13.48015.641

Si substrateSi

120.00

0.000

0.000

SET: one momentary

SEL: no occurrence#1 Possibly not to the irradiation effect, but to electromagnetic noise.

For both Si10 + and Br14 +, the range and LET (Linear Energy Transfer) in the Si sensitive layer are
insufficient for the tested IC. Next approaches with other ions and modified test methods are under1

Nihon Dempa Kogyo Co., Ltd. (NDK)

2Japan Aerospace Exploration Agency

46

consideration for evaluation of single event to calculate the threshold LET and saturation cross-sections.
(2) Experimental results in February 2022
Irradiation tests with 66 MeV Si10 + and 72 MeV Cl11 + were performed. The test results and calculated
LET for Si10 + are described in the table below (the Cl11 + data is omitted).

ManuParts
facturerCcComponent

E

F

c

b

b

mass number

Energy [MeV]

Si

28

66.00

After passing thru. the substance

Test results−

Range in Si[μm]
12.40822.720Au

0.20

12.53222.041

Al

13.70

13.629

Semiconductor
sensitive layer

6.298 SET: no occurrence

Si

1.00

13.237

5.298

Si substrateSi

152.00

0.000

0.000

Initial−−12.40822.720Initial−Scatterer
Wiring layer

ScattererD

Thickness
Material[μm]

Ion

LET in Si[M eV/(mg/cm2)]

SEL: no occurrence

Au

0.20

12.53222.041

Protective film

Kapton4.00

13.03618.903 SEL: no occurrence

Wiring layer

Al

13.60

11.6103.340 SET: no occurrence

Semiconductor
sensitive layer

Si

1.00

9.823

2.340

Si substrateSi

151.00

0.000

0.000

Initial−−12.40822.720

Scatterer

Au

0.20

12.53222.041

Wiring layer

Al

4.20

13.273

Semiconductor
sensitive layer

17.216 SET: no occurrence

Si

1.00

13.40416.216

Si substrate

Si

291.00

0.000

0.000

Initial−−12.40822.720

Scatterer

Au

0.20

12.53222.041

Wiring layer

Al

5.10

13.409

Semiconductor
sensitive layer

16.181 SET: no occurrence

Si

1.00

13.541

15.181

Si substrateSi

213.00

0.000

0.000

SEL: no occurrence

SEL: no occurrence

For both Si10 + and Cl11 +, the range and LET in the Si sensitive layer are insufficient for the tested
IC, causing no single event error, from which the threshold LET and saturated cross-sections are to be
calculated. We will continue to consider the calculation of the error rate on the actual satellite orbits, theapplicability of parts in space, and test methods in future.
References[1] Nihon Dempa Kogyo Co., Ltd. Outgas Analysis System
https://www.ndk.com/jp/products/search/outgas/index.html[2] Y. Tsuchiya et al., IEEE Sensors Journal 21 (2021) 10530.
https://ieeexplore.ieee.org/document/9351992

47

6.3

Unusual enhancement of self-field critical current density in YBa2Cu3O7
films by several-tens-MeV Au ion irradiation

H. Matsui1, I. Yamaguchi1
Applications of second-generation high-temperature superconducting wires consisting of YBa2Cu3O7(YBCO, critical temperature Tc ~ 92 K) films are roughly categorized into two groups based on theenvironment of their use: (i) high-temperature (> 65 K), self-field applications such as power-transmission
lines, and (ii) low-temperature (< 65 K), in-magnetic-field applications such as motors and generators. In
both groups, research efforts are focused on how to maximize the critical current density (Jc) via
microstructure modification. However, in many kinds of YBCO films, enhancing Jc by such modification ismore difficult at self-field (Jcsf) than that at applied magnetic fields [1, 2]. Lack of sufficient number ofexamples of “Jcsf” enhancement in YBCO films makes it unclear what type of microstructure in the material
is ideal for application (i) above, namely, for Jcsf at high temperatures.
In this work, we performed 24- to 84-MeV Au-ion irradiation on 1-μm-thick YBCO films prepared byfluorine-free metal organic deposition (FF-MOD) to gain insight into what type of microstructure in YBCO
films is effective for Jcsf at high temperatures. We observed significant enhancement (up to 63%) in Jcsf in
FF-MOD YBCO films at 77 K by introducing the discontinuous 1D irradiation defects of 5-10 nm indiameter, ~20 nm in size along an ion track, and a ~20 nm gap between defects in an ion track, which are
directed in the c-axis.
We deposited 1.0-μm-thick YBCO epitaxial films (Tc = 90.8 K) on CeO2-buffered SrTiO3 substrates by
FF-MOD [3]. For comparison, we also used 0.7-μm-thick YBCO epitaxial films (CERACO ceramic coating
GmbH, Tc = 87.9 K) on SrTiO3 substrates deposited by thermal co-evaporation. The Au-ion irradiation at
different ion energies Ei =24, 44, 66, 75, and 84 MeV at room temperature was performed under a vacuum
pressure of 1×10-6 Torr with the 6MV tandem accelerator at UTTAC. The specimens were fixed to a sample
holder by electrically conductive adhesive tape to avoid electric charging by the ion irradiation. The incident
angle of ions was set normal to the film surface. Irradiation dose of 3×108 − 1×1012 cm-2 was controlled bybeam current and exposure time. Jc and Tc were measured inductively with a Cryoscan (THEVA).
Figures 1(a)−(e) show the dose dependence of Jcsf in Au-irradiated FF-MOD YBCO films [4]. For
comparison, Jcsf values measured before irradiation (“as-grown”; open symbols) are also plotted in the same
horizontal position as those after irradiation (filled symbols). At Ei=66 to 84 MeV, Jcsf is significantly
enhanced up to Jcsf = 2.2 MA/cm2 with a maximum enhancement factor of Jcsf /Jcsf as-grown=1.6, while theenhancement is only slight at Ei =24 or 44 MeV, i.e., up to Jcsf = 1.7 MA/cm2 with a maximum enhancement
factor of 1.2. The present observation of Jcsf enhancement itself is unusual in YBCO films. In Fig. 1(f), theco-evaporated YBCO film shows as-grown Jcsf values higher than those of the FF-MOD YBCO films, andalso shows a negligibly small increase in Jcsf after irradiation at 66 MeV, in contrast to the case in Fig. 1(c).
This result is consistent with the absence of Jcsf enhancement previously reported in the ion-irradiation

1National Institute of Advanced Industrial Science and Technology (AIST)48

studies on YBCO films deposited by various methods [1]. This contrast in Jcsf enhancement between FFMOD and other film-deposition methods can be attributed to different microstructures in the as-grownsamples. Namely, small pin density, i.e., clean microstructure, in FF-MOD YBCO films can cause therelatively low as-grown Jcsf (~ 1.5 MA/cm2), however it can be compensated by the irradiation defects,
resulting in enhanced Jcsf. This interpretation is supported by our results of film-thickness dependence of theirradiation effect and our microstructure imaging [4].
FF-MOD t=1.0 μm
44 MeV

66 MeV

75 MeV

66 MeV

84 MeV3

77 K
self-field2

2.0

24 MeVCo-evaporation t=0.7 μm

Jc (MA/cm )2

Jc (MA/cm )2.5

Irradiated(filled)

1.5

1.0

As-grown(open)

(a)
10

9

11

10

(b)
10

(c)
9

10

11

10

(d)
9

10

11

10

11

(e)

2

1
9

10

10

11

(f)
10

9

11

10

-2

-2

Dose (cm )Dose (cm )Fig. 1. Dose dependence of Jcsf at 77 K in Au-irradiated YBCO films [4]. For comparison, Jcsf values measured
before irradiation (as-grown; open symbols) are plotted are also plotted in the same horizontal position as
those after irradiation (filled symbols).

References[1] S. R. Foltyn et al., Nature Mater. 6 (2007) 631.
[2] J. P. F. Feighan et al., Sci. Technol. 30 (2017) 123001.
[3] K. Tsukada et al., Physica C 458 (2007) 29.
[4] H. Matsui and I. Yamaguchi, Jpn. J. Appl. Phys. 61 (2022) 043001.

49

Study on mutagenesis with 15N-resonant nuclear reaction
and radiation effects

6.4

I. Suzuki, T. Yang, T. Ikeda, K. Sasa, S. Ishii, K. Tomita1, Y. Iwata1
Marine microalgae draw people’s attention as a new Blue Carbon to provide a generic technology of the
supply chain with high-density culture. The authors aim to mutate Haptophyte of marine microalgae toenhance the productivity of long-chain unsaturated alkyl ketone (alkenone) that enables conversion tocompletely interchangeable biofuel (drop-in-fuel) for conventional petroleum-derived fuel. Furthermore,aminolevulinic acid (5-ALA), that can be applicable to new cancer therapy is also the featured product ofthe mutation Haptophyte strains.
Resonant nuclear reaction 15N(p, α1γ)12C (15N-RNR) causes such strong structural modification of DNA
as never induced by heavy ion irradiation, since high-density electronic excitation by the 12C and 4He productions takes place inside DNA molecule efficiently. Structural modification of the target genes in DNA can beachieved by substituting 98% constituent nitrogen atoms of the targeted bases with isotopic tagged 15N.
We have developed a vacuum flange to encapsulate cells alive in vacuum, named CS vacuum flange thatpossesses a metallic but soft shieling feature [1], since the resonance energy of the 15N-RNR is too low for
any proton beam to keep the precise resonance energy after being extracted into the atmosphere. Coveringliving mammalian cells in a
culturemediumpolyphenylene

withsulfideafilm(Torelina™, TORAY) with 4 μm
inthicknessandshieling

together with the medium in
vacuum by the CS vacuum
flange, we succeeded in protonbeam irradiation to the cells
alive (see Fig. 1). We used themodel RGM-GFP (normal cell)that were cultivated in a medium
containing 5-ALA labeled with15

N (15N_5-ALA).
Proton beam irradiation was

performed with utilizing the C- Fig. 1. CS vacuum flange to encapsulate cells alive in vacuum.
beam

courseofthe

1MV Polyphenylene sulfide film (Torelina™, TORAY) is tolerant of hydrolysis andis suited for shieling cells together with the solution in vacuum. Both 15Nlabbeled model cells of RGM-GFP (normal cells) and RGK-KO (cancer cells)
UTTAC. After rinsing the 15N_5- were covered with a Torelina film of 4 μm in thickness and the cells were
ALA medium, 15N-labeled living irradiated with a proton beam through the film to detect the 4.43 MeV gammarays emitted from 15N_NR.

Tandetron

acceleratorin

1National Institute of Advanced Industrial Science and Technology (AIST).

50

Fig. 2. Cell images alive after proton irradiation and their survival rate.
(a)~(c) Fluorescence microscopy images of the RGM-GFP cells alive (upper stage) and the same images of decease
cells revealed with DAPI stain (lower stage). The beam irradiation area is indicated in the cell images by a whitecircle. The survival rate of the RGM-GFP cells as a function of proton dose (nC) is shown in (d).

cells were irradiated with a proton beam. First of all, we demonstrated the 15N-RNR in collision with the15

N accumulated in the cells by detecting the 4.43 MeV gamma-rays specific to the 15N-RNR (see Fig. 1).

The energy shift at the 1210 keV resonance energy after passing through the 4 μm Torelina™ film was 110
keV. By subtracting the energy loss of proton in the film, which was evaluated with the stopping power
given by the SRIM-2013 code [2], the thickness of the encapsulate solution was estimated as 4 μm in H2O
terms. The proton path is shorter than the average diameter of the cells.
Using the method for encapsulating the living cells in vacuum, the authors investigated the survival rateof the RGM-GFP cells in proton irradiation. We can observe the green fluorescence from the living RGMGFP cells, and DNAs in the deceased cells were stained with 4',6-diamidino-2-phenylindole (DAPI) stain
under the fluorescent microscopy. The fluorescence microscopy images of the living RGM-GFP cells after
proton irradiation are shown in the upper stages in Fig. 2a-c. On the other hand, the same images of thedeceased cells were revealed with DAPI staining of nucleic acids, as shown in the lower stages. The survival
rate can be set as the ratio of the number of living cells (in the upper stages) to the total cells (sum in theupper and lower stages). The results of the survival rate of the RGM-GFP cells show a logarithm curve as afunction of the proton dose in particle charge terms (nC) (see Fig. 2d).
The present results substantiated that 15N-RNR is applicable to mutagenesis of microalgae using themethod for encapsulating living cells in vacuum, even though the resonance energy of 15N-RNR is lower
than 1 MeV.

Also, 15N-RNR is useful for quantitative evaluation of 15N accumulated specifically in thecancer cells.
References[1] Y. Iwata and A. Chayahara, US patent 7648586 2010/01/19, JP patent 5392752 2013/10/08.
[2] J. F. Ziegler et al., http://srim.org/

51

7.
LIST OF PUBLICATIONS AND PRESENTATIONS

ON-LINE
SYMPOSIUM

7.1

Peer-reviewed and proceedings papers

ACCELERATOR AND RERATED FACILITIES
1. G. Yoshida, H. Matsumura, H. Nakamura, A. Toyoda, K. Masumoto, T. Miura, K. Sasa, T. Moriguchi,“Survey Methodology for the Activation of Beamline Components in an Electrostatic Proton
Accelerator”, Radiation Safety Management 20 (2021) 1. [DOI:10.12950/rsm.200813]

NUCLEAR AND ATOMIC PHYSICS
1. Y. Kimura, M. Mihara, K. Matsuta, M. Fukuda, Y. Otani, G. Takayama, T. Izumikawa, N. Noguchi,
M. Ogose, Y. Sato, K. Takatsu, T. Ohtsubo, H. Takahashi, S. Momota, H. Okumura, T. Moriguchi,
A. Ozawa, A. Kitagawa, S. Sato, “Development of a small Beta-NMR system using Halbach Array
permanent magnet”, Hyperfine Interact. 243 (2022) 1. [DOI:10.1007/s10751-021-01789-5]
2. Y. Otani, M. Mihara, K. Matsuta, M. Fukuda, R. Wakabayashi, N. Okimoto, M. Fukutome, Y.
Kimura, G. Takayama, T. Izumikawa, N. Noguchi, M. Ogose, M. Sato, K. Takatsu, T. Ohtsubo, D.
Nishimura, H. Takahashi, S. Sugawara, A. Gladkov, H. Ishiyama, A. Kitagawa, S. Sato, S. Momota,
H. Okumura, T. Moriguchi, A. Ozawa, N. Kaname, A. Yano, “Application of spin polarized 19O beam
to the study of oxygen motion in solid oxide fuel cell materials”, Hyperfine Interact. 242 (2021) 47.
[DOI:10.1007/s10751-021-01776-w]
3. A. Ozawa for Rare-RI Ring collaboration, “Past and future for Rare-RI Ring”, JPS Conf. Proc. 35 (2021)
011011. [DOI:10.7566/JPSCP.35.011011]
4. D. Nagae, S. Omika, Y. Abe, Y. Yamaguchi, F. Suzaki, K. Wakayama, N. Tadano, R. Igosawa,
K. Inomata, H. Arakawa, K. Nishimuro, T. Fujii, T. Mitsui, T. Yamaguchi, T. Suzuki, S. Suzuki,
T. Moriguchi, M. Amano, D. Kamioka, A. Ozawa, S. Naimi, Z. Ge, Y. Yanagisawa, H. Baba,
S. Michimasa, S. Ota, G. Lorusso, Y. A. Litvinov, M. Wakasugi, T. Uesaka, Y. Yano,“First demonstration of mass measurements for exotic nuclei using Rare-RI Ring”, JPS Conf. Proc. 35(2021) 011014. [DOI:10.7566/JPSCP.35.011014]
5. S. Suzuki, A. Ozawa, T. Moriguchi, M. Amano, D. Kamioka, Y. Ichikawa, Y. Tajiri, K. Hiraishi,
T. Matsumoto, D. Nagae, Y. Abe, S. Naimi, H. Li, T. Yamaguchi, S. Omika, Z. Ge, K. Wakayama,
N. Tadano, H. Arakawa, K. Inomata, T. Kobayashi, A. Kitagawa, S. Sato, “Performance of a Time-OfFlight detector and demonstration of a novel position-sensitive detector for mass measurements with
the Rare-RI Ring”, JPS Conf. Proc. 35 (2021) 011017. [DOI:10.7566/JPSCP.35.011017]

52

6. K. Inomata, T. Yamaguchi, Y. Abe, M. Amano, H. Arakawa, T. Fujii, D. Kamioka, A. Kitagawa,H. Li, T. Moriguchi, D. Nagae, S. Omika, A. Ozawa, S. Sato, S. Suzuki, T. Suzuki, K. Wakayama,“Basic Study on Delta Ray Detection for the Determination of In-Ring Revolution Time”, JPS Conf.
Proc. 35 (2021) 011020. [DOI:10.7566/JPSCP.35.011020]
7. H. Arakawa, Y. Yamaguchi, Y. Abe, M. Amano, K. Inomata, D. Kamioka, A. Kitagawa, H. Li,
T. Moriguchi, D. Nagae, S. Omika, A. Ozawa, S. Sato, S. Suzuki, T. Suzuki, K. Wakayama, “Propertiesof a thin YAP(Ce) scintillation counter for heavy ions”, JPS Conf. Proc. 35 (2021) 011022.
[DOI:10.7566/JPSCP.35.011022]
8. Z. Ge, S. Naimi, D. Nagae, Y. Abe, S. Omika, T. Uesaka, F. Suzaki, H. Li, Y. Yamaguchi, M. Wakasugi,
K. Wakayama, T. Yamaguchi, A. Ozawa, H. Arakawa, K. Inomata, T. Kobayashi, K. Nishimuro,
S. Suzuki, T. Moriguchi, D. Kamioka, M. Mukai, M. Amano, A. Kitagawa, S. Sato, G. Lorusso,
Y. Yano, “Development of mirror-type MCP detectors for mass measurements at the Rare-RI Ring”,
JPS Conf. Proc. 35 (2021) 011023. [DOI:10.7566/JPSCP.35.011023]
9. K. Wakayama, T. Yamaguchi, Y. Abe, M. Amano, H. Arakawa, Z. Ge, K. Inomata, D. Kamioka,
A. Kitagawa, T. Kobayashi, H. Li, T. Moriguchi, D. Nagae, S. Omika, A. Ozawa, S. Sato, S. Suzuki,
T. Suzuki, N. Tadano, “A Simple Readout Method for a Position-Sensitive Detector Using Plastic
Scintillator Bars”, JPS Conf. Proc. 35 (2021) 011024. [DOI:10.7566/JPSCP.35.011024]
10. H. Li, Z. Ge, S. Naimi, D. Nagae, Y. Abe, T. Uesaka, F. Suzaki, M. Wakasugi, S. Omika, Y. Yamaguchi,
T. Yamaguchi, K. Wakayama, H. Arakawa, K. Inomata, A. Ozawa, S. Suzuki, T. Moriguchi, “MCPwith delay-line anode used for position sensitive detector at Rare RI Ring”, JPS Conf. Proc. 35 (2021)
011025. [DOI:10.7566/JPSCP.35.011025]
11. S. Omika, T. Yamaguchi, Y. Abe, M. Amano, H. Arakawa, Z. Ge, K. Inomata, D. Kamioka, H. Li,
H. Miura, T. Moriguchi, D. Nagae, S. Naimi, K. Nishimuro, A. Ozawa, F. Suzaki, S. Suzuki, T. Suzuki,
N. Tadano, T. Uesaka, M. Wakasugi, K. Wakayama, Y. Yanagisawa, Y. Yamaguchi, “Development ofexperimental devices for precise mass measurements at the Rare-RI Ring Facility”, JPS Conf. Proc. 35(2021) 011026. [DOI:10.7566/JPSCP.35.011026]
12. X. Zhou, M. Zhang, M. Wang, Y. H. Zhang, Y. J. Yuan, X. L. Yan, X. H. Zhou, H. S. Xu, X. C. Chen,
Y. M. Xing, R. J. Chen, X. Xu, P. Shuai, C. Y. Fu, Q. Zeng, M. Z. Sun, H. F. Li, Q. Wang, T. Bao,
M. Si, H. Y. Deng, M. Z. Liu, T. Liao, J. Y. Shi, Y. N. Song, J. C. Yang, W. W. Ge, Yu. A. Litvinov,
S. A. Litvinov, R. S. Sidhu, T. Yamaguchi, S. Omika, K. Wakayama, S. Suzuki, T. Moriguchi, “In-ringvelocity measurement for isochronous mass spectrometry”, Phys. Rev. Accel. Beams 24 (2021) 042802.
[DOI:10.1103/PhysRevAccelBeams.24.042802]

53

13. M. Ahmed, Y. X. Watanabe, Y. Hirayama, M. Mukai, J. H. Park, P. Schury, Y. Kakiguchi, A. Ozawa,
M. Oyaizu, M. Wada, H. Miyatake, “β-γ spectroscopy of the 195Os nucleus”, Phys. Rev. C 103 (2021)
054312. [DOI:10.1103/PhysRevC.103.054312]

ACCELERATOR MASS SPECTROMETRY
1. K. Kanzawa, F. Miyake, K. Horiuchi, K. Sasa, K. Takano, M. Matsumura, T. Takahashi, Y. Motizuki,
K. Takahashi, Y. Nakai, K. Ohtani, Y. Tada, Y. Ochiai, H. Motoyama, H. Matsuzaki, A. Yamazaki,
Y. Muramatsu, T. Yamagata, “High-Resolution 10Be and 36Cl Data from the Antarctic Dome Fuji Ice
Core (~100 years around 5480 BCE): An Unusual Grand Solar Minimum Occurrence?”, Journal ofGeophysical Research: Space Physics 126 (2021) e2021JA029378. [DOI:10.1029/2021JA029378]
2. K. Hain, M. Martschini, F. Gülce, M. Honda, J. Lachner, M. Kern, J. Pitters, F. Quinto,
A. Sakaguchi, P. Steier, A. Wiederin, A. Wieser, A. Yokoyama, R. Golser, “Developing accelerator
mass spectrometry capabilities for anthropogenic radionuclide analysis to extend the set ofoceanographic tracers”, Front. Mar. Sci. 9 (2022) 837515. [DOI:10.3389/fmars.2022.837515]
3. A. Nakajima, K. Teranishi, A. Yokoyama, A. Sakaguchi, K. Hain, R. Morita, A. Sato, A. Nagai, D. Mori,
Y. Komori, T. Yokota, Y. Wang, H. Haba, “Measurement of the isotopic ratio of Np-236 to Np-237 in
Th-232 + Li-7 reaction products by accelerator mass spectrometry”, RIKEN accel. Prog. Rep. 54 (2021)
142.
4. K. Sakata, Y. Takahashi, S. Takano, A. Matsuki, A. Sakaguchi, H. Tanimoto, “First X-ray Spectroscopic
Observations of Atmospheric Titanium Species: Size Dependence and the Emission Source”, Environ.
Sci. Technol. 55 (2021) 10975. [DOI:10.1021/acs.est.1c02000]

BEAM AND ISOTOPE APPLICATIONS
1. H. Kudo, H. Naramoto, M. Sataka, S. Ishii, K. Sasa, S. Tomita, “Depth resolution of transmission ERDA
for H in Al under nuclear-elastically enhanced recoiling of H by 8 MeV He”, J. Phys.: Condens. Matter
33 (2021) 465901. [DOI:10.1088/1361-648X/ac17ac]
2. Y. Sugisawa, I. Harayama, Y. Takimoto, T. Wakasugi, Y. Hirose, T. Hasegawa, S. Ishii, D. Sekiba,“Installation of TOF-E telescope ERDA in UTTAC at the University of Tsukuba: analysis of metalnitride-based multi-layer coatings on glasses”, Nucl. Insrum. Methods Phys. Res. B 503 (2021) 68.
[DOI:10.1016/j.nimb.2010.07.006]

54

3. Y. Liu, Y. Hisamatsu, S. Sharmin, D. Oshima, S. Iwata, T. Kato, D. Sekiba, E. Kita, H. Yanagihara,“Topotactic crystal structure transformation from spinel ferrite to wüstite in epitaxial Fe3O4 films via Kr
ion irradiation”, J. Vac. Sci. Technol. A39 (2021) 033403. [DOI:10.1116/6.0000885]
4. R. Murase, H. Tsuchida, S. Nakagawa, S. Tomita, A. Chiba, K. Nakajima, T. Majima, M. Saito,“Effect of structure and orientation of incident carbon-cluster ions Cn+(n≤4) on secondary-ion
emission induced by electronic excitation”, Phys. Rev. A103 (2021) 062812.
[DOI:10.1103/PhysRevA.103.062812]
5. M. Sumiya, Y. Takahara, A. Alghamdi, Y. Nakayama, F. Uesugi, Y. Harada, A. Uedono, Y. Imanaka,“Growth of AlxGa1-xN/InyGa1-yN hetero structure on AlN/sapphire templates exhibiting Shubnikov-de
Haas oscillation”, J. Cryst. Growth 574 (2021) 126324. [DOI:10.1016/j.jcrysgro.2021.126324]
6. A. Uedono, R. Tanaka, S. Takashima, K. Ueno, M. Edo, K. Shima, K. Kojima, S. F. Chichibu,
S. Ishibashi, “Dopant activation process in Mg-implanted GaN studied by monoenergetic positronbeam”, Sci. Rep. 11 (2021) 20660. [DOI:10.1038/s41598-021-00102-2]
7. H. Okumura, R. Jinno, A. Uedono, M. Imura, “Optical and electrical properties of silicon-implanted
α-Al2O3”, Jpn. J. Appl. Phys. 60 (2021) 106502. [DOI:10.35848/1347-4065/ac21af]
8. P. Muhammed Shafi, E. Kurian, N. Joseph, S. Sellaiyan, A. Uedono, A. Chandra Bose, “Effect of Ag
doping on crystallinity and microstrain of LaMnO3 nanoparticles: Confirmations of defect levels withpositron lifetime and Doppler-broadening calculations”, Phys. B 615 (2021) 413087.
[DOI:10.1016/j.physb.2021.413087]
9. A. Sagara, H. Yabe, X. Chen, B. Put, T. Hantschel, M. Mees, H. Arase, Y. Kaneko, A. Uedono,
P. M. Vereecken, “Interfacial Conductivity Enhancement and Pore Confinement ConductivityLowering Behavior inside the Nanopores of Solid Silica-gel Nanocomposite Electrolytes”, ACS Appl.
Mater. Interfaces 13 (2021) 40543. [DOI:10.1021/acsami.1c09246]
10. T. Hamada, Y. Nakanishi, K. Okada, S. Tsukada, A. Uedono, J. Ohshita, “Thermal insulating propertyof silsesquioxane hybrid film induced by intramolecular void spaces”, ACS Appl. Polym. Mater. 3(2021) 3383. [DOI:10.1021/acsapm.1c00344]
11. A. Uedono, J. Takino, T. Sumi, Y. Okayama, M. Imanishi, S. Ishibashi, Y. Mori, “Vacancy-type defects
in bulk GaN grown by oxide vapor phase epitaxy probed using positron annihilation”, J. Cryst. Growth570 (2021) 126219. [DOI:10.1016/j.jcrysgro.2021.126219]
12. M. Akazawa, R. Kamoshida, S. Murai, T. Kachi, A. Uedono, “Low-temperature annealing behavior of55

defects in Mg-ion-implanted GaN studied using MOS diodes and monoenergetic positron beam”, Jpn.
J. Appl. Phys. 60 (2021) 016502. [DOI:10.35848/1347-4065/abcf08]
13. K. Shima, R. Tanaka, S. Takashima, K. Ueno, M. Edo, K. Kojima, A. Uedono, S. Ishibashi,
S. F. Chichibu, “Improved minority carrier lifetime in p-type GaN segments prepared by vacancyguided redistribution of Mg”, Appl. Phys. Lett. 119 (2021) 182106. [DOI:10.1063/5.0066347]
14. L. Y. Li, K. Shima, M. Yamanaka, K. Kojima, T. Egawa, A. Uedono, S. Ishibashi, T. Takeuchi,
M. Miyoshi, S. F. Chichibu, “Reduced nonradiative recombination rates in c-plane Al0.83In0.17N films
grown on a nearly lattice-matched GaN substrate by metalorganic vapor phase epitaxy”, Appl. Phys.
Lett. 119 (2021) 019105. [DOI:10.1063/5.0066263]

7.2

Reviews and books

1. 冨田成夫，山崎明義，石井 聰，笹 公和，左高正雄，楢本 洋，工藤 博，”透過 ERDA によるアルミニウム中水素の 3 次元分布計測”，応用物理学会放射線分科会誌「放射線」47 (2021)
15.

7.3

Poster and oral presentations

1. 森口哲朗, 小沢 顕, 冨田啓介, 大和良広, 林 実香, 要 直登, 景澤怜央, 向井もも, 矢野朝陽,“回転磁場を用いた 25Al, 29P の核磁気モーメントの符号測定”, 日本物理学会第 77 回年次大会,
オンライン開催（2022 年 3 月 15−19 日).
2. 矢野朝陽, 小沢 顕, 森口哲朗, 要 直登, 福田光順, 三原基嗣, 福留美樹, 高山 元, 木村容子,
田口 諒, 本多裕也, 林 双葉, 田中聖臣, 鈴木 健, 山口貴之, 神田真矩, 関 響咲, 西村太樹,
高橋弘幸, 菅原奏来, 宇根千晶, 大坪 隆, 野口法秀, 泉川卓司, 佐藤眞二, 福田茂一,
北川敦志, “反応断面積測定のための固体重水素標的の開発”, 日本物理学会第 77 回年次大会,
オンライン開催 (2022 年 3 月 15−19 日).
3. 森口哲朗, 小沢 顕, 堀内 渉, 阿部康志, 北川敦志, 向井もも, 長江大輔, 佐藤眞二, 鈴木伸司,
鈴木 健, 山口貴之, “固体水素標的を用いた反応断面積のエネルギー依存性”, 第 1 回日本量子医科学会学術大会, オンライン開催 (2021 年 12 月 10−11 日).
4. 要 直登, 森口哲朗, 小沢 顕, 山口貴之, Sarah Naimi, 向井もも, 鈴木伸司, “薄膜からの二次電子放出を利用した RI ビーム位置敏感型検出器の開発”, 第 1 回日本量子医科学会学術大会,
オンライン開催 (2021 年 12 月 10−11 日).

56

5. 山口貴之, 鈴木 健, 福田光順, 西村太樹, 田中聖臣, 長江大輔, 小沢 顕, 森口哲朗, 大坪 隆,“高エネルギー重イオンビームによる粒子検出器の開発と荷電変化反応の研究”, 第 1 回日本
量子医科学会学術大会, オンライン開催 (2021 年 12 月 10−11 日).
6. T. Moriguchi, A. Ozawa, Y. Yamato, M. Hayashi, R. Kagesawa, N. Kaname, M. Mukai, K. Tomita,
A. Yano, “Status of Lamb-shift polarized ion source at 6MV tandem accelerator in UTTAC and its
application to nuclear physics”, The 24th International Spin Symposium (SPIN2021), Matsue,
Shimane, Japan (Hybrid), Gather Online (Oct. 18−22, 2021).
7. T. Moriguchi, A. Ozawa, K. Tomita, Y. Yamato, M. Hayashi, N. Kaname, M. Mukai, A. Yano,“Measurement of the sign of nuclear moment for unstable nuclei 25Al and 29P by using rotating
magnetic field”, 3rd International Conference on Hyperfine Interactions and their Applications(HYPERFINE2021), Brasov, Romania (Hybrid), Gather Online (Sep. 5−10, 2021).
8. 森口哲朗, 小沢 顕, 冨田啓介, 要 直登, 矢野朝陽, 林 実香, 山口貴之, 鈴木 健, 梶木大輔,
濱川大貴, 原山朔弥, 大津美沙紀, Sarah Naimi, George Hudson-Chang, 山口由高, 向井もも,
長江大輔, 鈴木伸司, 西村太樹, 髙橋弘幸, 北川敦志, 佐藤眞二, 阿部康志, “RI ビーム飛行時
間検出器の開発 -理研稀少 RI リングのための検出器”, 2020 年度 HIMAC 共同利用研究成果
発表会, オンライン開催 (2021 年 6 月 7−10 日).
9. T. Yamaguchi “Precision experiments of exotic nuclei at the storage rings”, Tsukuba Global Science
Week 2021, Gather Online (Sep. 6−11, 2021). (invited)
10. 秩父重英, 嶋 紘平, 小島一信, 高島信也, 上野勝典, 江戸雅晴, 井口紘子, 成田哲生,
片岡恵太, 石橋章司, 上殿明良, “エピタキシャル成長及びイオン注入により作製された GaN
基板上 Mg 添加 p 型 GaN の室温フォトルミネッセンス寿命”, 第 69 回応用物理学会春季学術講演会, 青山学院大学 ハイブリッド開催(2022 年 3 月 23 日). （招待講演）

11. Y. Wakiyama, M. Matumura, T. Matsunaka, S. Hirao, K. Sasa, “Behavior of 129I in the Abukuma riverduring two high-flow events in 2018”, EGU General Assembly, vEGU21: Gather Online(Apr. 19−30, 2021).
12. K. Sasa, M. Matsumura, T. Takahashi, “Development of Non-Radiocarbon Accelerator Mass
Spectrometry at the University of Tsukuba”, Technical Meeting on Developments in NonRadiocarbon Accelerator Mass Spectrometry Techniques and Relevant Applications, International
Atomic Energy Agency (IAEA), Gather Online (Oct. 11−14, 2021).
13. K. Sasa, Y. Ochiai, Y. Tosaki, T. Matsunaka, T. Takahashi, M. Matsumura, K. Sueki, “Chlorine-36
deposition at Tsukuba, Japan, after the Fukushima Daiichi Nuclear Power Plant accident”, The 15th57

International Accelerator Mass Spectrometry Conference (AMS-15), Sydney, Australia, Gather Online(Nov. 15−19, 2021).
14. K. Sasa, M. Matsumura, T. Matsunaka, T. Takahashi, Y. Satou, N. Kinoshita, H. Matsuzaki, K. Sueki,“Determination of I-129/I-131 in surface soils related to the Fukushima Daiichi Nuclear Power Plant
accident”, The 15th International Accelerator Mass Spectrometry Conference (AMS-15), Sydney,
Australia, Gather Online (Nov. 15−19, 2021).
15. M. Matsumura, K. Sasa, A. Sakaguchi, T. Matsunaka, T. Takahashi, K. Sueki, “Status report of the
Tsukuba 6MV multi-nuclide AMS system: Progress in iodine-129 AMS”, The 15th International
Accelerator Mass Spectrometry Conference (AMS-15), Sydney, Australia Gather Online(Nov. 15−19, 2021).
16. M. Matsumura, K. Sasa, Y. Ochiai, Y. Tosaki, T. Matsunaka, T. Takahashi, K. Sueki, ”Regional
dependence of Be-10 and Cl-36 variations in rainwater at the Sea of Japan and Pacific sides of Japan”,
The 15th International Accelerator Mass Spectrometry Conference (AMS-15), Sydney, Australia,
Gather Online (Nov. 15−19, 2021).
17. T. Matsunaka, S. Nagao, S. Ochiai, T. Takahashi, M. Matsumura, K. Sueki, K. Sasa, “Anthropogenic
iodine-129 depositions at the Sea of Japan and Pacific sides of the Japanese archipelago, during
2017−2018”, The 15th International Accelerator Mass Spectrometry Conference (AMS-15), Sydney,
Australia, Gather Online (Nov. 15−19, 2021).
18. T. Matsunaka, S. Nagao, M. Inoue, Y. Taniuchi, H. Kasai, T. Takahashi, M. Matsumura,
K. Sueki, K. Sasa, “Surface distribution of iodine-129 in the southwestern Okhotsk Sea in 2018”,
The 15th International Accelerator Mass Spectrometry Conference (AMS-15), Sydney, Australia,
Gather Online (Nov. 15−19, 2021).
19. K. Sueki, Y. Ohta, H. Yokoyama, Y. Ochiai, S. Hosoya, M. Honda, Y. Satou, T. Matsunaka,
T. Takahashi, M. Matsumura, K. Sasa, “Chlorine-36 and Iodine-129 Inventories in Difficult-to-return
Zone in Fukushima”, The 15th international Accelerator Mass Spectrometry Conference (AMS-15),
Sydney, Australia, Gather Online (Nov. 15−19, 2021).
20. H. Shen, S. Shi, J. Tang, M. Qi, S. Wei, M. Liu, W. Li, Z. Guofeng, K. Sasa, W. Mingjun,
G. Shanhua, D. Junyan, “The ¹⁴C-AMS technology and its applications for evaluation of the propertiesof highly permeable aquifers cause by large volume water injection in oil field”, Radiocarbon in theEnvironment III Conference, Gliwice, Poland (Jul. 5−6, 2021).

58

21. 杉澤悠紀, 小林 成, 岸奈津子, 清水亮太, 一杉太郎, 関場大一郎, ”核反応法を用いた全固体リチウムイオン電池中 Li のオペランド深さ分布測定”, 日本物理学会 2021 年秋季大会, オンラ
イン開催(2021 年 9 月 20−23 日). (日本物理学会学生優秀発表賞受賞講演)

22. 冨田成夫, 菅沼瑠里, 畑田颯太, 川崎銀河, 椎名陽子, 左高正雄, 松田 誠, 今井 誠, 石井 聰,
笹 公和, “コンボイ電子収量におけるクラスター効果の入射粒子依存性”, 日本物理学会 2021
年秋季大会, オンライン開催(2021 年 9 月 20−23 日).

23. 笹 公和, 石井 聡, 高橋 努, 大和良広, 田島義一, 松村万寿美, 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” 日本加速器学会第 18 回年会, オンライン開催(2021 年 8 月 9−12 日).
24. 笹 公和，石井 聡，高橋 努，大和良広，田島義一，松村万寿美，森口哲朗，上殿明良,“筑波大学タンデム加速器施設 UTTAC の現状”，第 33 回 タンデム加速器及びその周辺技術の研究会, 国立研究開発法人量子科学技術研究開発機構,

オンライン開催(2021 年 6 月 24−25 日).
25. 笹 公和, 落合悠太, 松村万寿美, 高橋 努, 松中哲也, “加速器質量分析法を用いた長半減期放射性ハロゲン 36 Cl と 129 I の高感度検出による降下量変動の比較研究”, 第 82 回応用物理学会
秋季学術講演会, オンライン開催 (2021 年 9 月 10−13 日).
26. 吉田 剛, 松村 宏, 中村 一, 豊田晃弘, 三浦太一, 桝本和義, 笹 公和, 森口哲朗,
松村万寿美, “可搬型 γ 線イメージング装置 GeGI5 による加速器放射化評価の可能性”, 日本
放射化学会第 65 回討論会 (2021), オンライン開催 (2021 年 9 月 22−24 日).
27. 椎根大輔, 坂口 綾, 笹 公和, 松村万寿美, 高橋 努, 末木啓介, 山﨑信哉, “核分裂生成核種
135

Cs の測定法確立に向けた取り組みと水圏科学研究への応用”, 2021 年度日本地球化学会第68 回年会, 弘前大学, ハイブリッド開催 (2021 年 9 月 1−15 日).
28. 西塚魁人, 坂口 綾, 笹 公和, 高橋 努, 松村万寿美, 三浦 勉, 浅井志保, 和田彩佳,
高久雄一, 山﨑信哉, 末木啓介, “水環境中における有機・無機ヨウ素同位体定量の試み”,
2021 年度日本地球化学会第 68 回年会, 弘前大学, ハイブリッド開催 (2021 年 9 月 1−15 日).
29. 大石脩人, 村尾吉輝, 新田紀子, 土田秀次, 冨田成夫, 笹 公和, 平田浩一, 柴田裕実,
平野貴美, 山田圭介, 千葉敦也, 齋藤勇一, 鳴海一雅, 星野 靖, “高速 C60 クラスターイオンビ
ーム照射による Si 表面構造の形態変化”, QST 高崎サイエンスフェスタ 2021, 国立研究開発
法人量子科学技術研究開発機構量子ビーム科学部門高崎量子応用研究所, ハイブリッド開催(2021 年 12 月 7−8 日).

59

30. 西塚魁人, 坂口 綾, 浅井志保, 本多真紀, 高久雄一, 笹 公和, 高橋 努, 松村万寿美,
和田彩佳, 三浦 勉, 山﨑信哉, 末木啓介, “水環境中における有機・無機ヨウ素同位体定量の試み”, 福島大学環境放射能研究所第 8 回成果報告会

福島原発事故後の環境放射能 ～研究成果から見える将来～，コラッセふくしま，福島県福島市 (2022 年 2 月 28 日−3 月 1 日).
31. 椎根大輔, 坂口 綾, 笹 公和, 松村万寿美, 高橋 努, 山﨑信哉, 末木啓介, “海水循環トレーサ
ー利用に向けた極微量放射性核種 135Cs の測定法確立”, 第 23 回「環境放射能」研究会,
オンライン開催 (2022 年 3 月 8−10 日).
32. 吉田 剛, 松村 宏, 中村 一, 豊田晃弘, 三浦太一, 桝本和義, 笹 公和, 森口哲朗,
松村万寿美,“可搬型 γ 線イメージング装置 GeGI5 を用いた加速器放射化評価への応用の見込み”, 第 23 回「環境放射能」研究会,
33. 笹 公和, 高橋 努, 椎根大輔,

オンライン開催 (2022 年 3 月 8−10 日).

松村万寿美, 坂口 綾, “Rb スパッタイオン源からの負イオンビームの生成”, 応用物理学会 2022 年第 69 回春季学術講演会，青山学院大学, ハイブリッド
開催 (2022 年 3 月 22−26 日).
34. 冨田成夫, 菅沼瑠里, 畑田颯太, 椎名陽子, 高橋 努, 石井 聰, 笹 公和, “コンボイ電子収量におけるクラスター効果の入射粒子依存性 II”, 日本物理学会 第 77 回年次大会, オンライン開催 (2022 年 3 月 15−19 日).
35. 畑田颯太，鈴木裕太郎，冨田成夫，”FPGA を用いた MCA の構築”, 原子衝突学会第 46 回年会, オンライン開催 (2021 年 10 月 26−28 日).
36. 上殿明良, 大島永康, 満汐孝治, ”陽電子消滅による配線材料の空孔検出 −後工程材料評価への応用− ”, 第 4 回量子ビーム計測クラブ研究会, オンライン開催 (2021 年 12 月 22 日).
（招待講演）
37. A. Uedono, M. Dickmann, W. Egger, C. Hugenschmidt, S. Ishibashi, “Study of point defects in groupIII nitrides by means of positron annihilation spectroscopy”, MLZ User meeting, Gather Online(Dec. 7, 2021). (invited)
38. A. Uedono, “Development of Information and Communication Technology (ICT), and its impact on
education”, JANET – Japanisches Kulturinstitut forum (Nov. 12, 2021). (invited)
39. A. Uedono, M. Dickmann, W. Egger, C. Hugenschmidt, S. Ishibashi, “Carrier trapping by vacancies insemiconductors studied using positron annihilation spectroscopy − a collaboration work between TUM
and University of Tsukuba”, The joint MLZ and physics department lecture series (May 3, 2021).
(invited)60

40. 上殿明良, “陽電子消滅を用いた材料の欠陥，自由体積の検出”, コンピュータによる材料開発・
物質設計を考える会 (CAMM フォーラム) , オンライン開催 (2021 年 4 月 2 日).
（招待講演）
41. 秩父重英, 嶋 紘平, 小島一信, 高島信也, 上野勝典, 江戸雅晴, 井口紘子, 成田哲生,
片岡恵太, 石橋章司, 上殿明良, “エピタキシャル成長及びイオン注入により作製された GaN
基板上 Mg 添加 p 型 GaN の室温フォトルミネッセンス寿命”, 応用物理学会春季学術講演会，
青山学院大学, ハイブリッド開催 (2022 年 3 月 22−26 日).

(第 43 回優秀論文賞受賞記念講演)42. 磯谷順一, 原 英之, 渡邊賢司, 角谷 均, 小野田 忍, 寺地徳之, 渡邊幸志, 梅田享英,
上殿明良, “HPHT ダイヤモンド結晶の EPR イメージング”,
ウム, 慶應義塾大学矢上キャンパス

第 36 回ダイヤモンドシンポジ(2021 年 11 月 17−19 日).

43. 上殿明良, 田中 亮, 高島信也, 上野勝典, 江戸雅晴, 嶋 紘平, 小島一信, 秩父重英,
石橋章司, “陽電子消滅を用いた Mg イオン注入により形成した p 型 GaN の Mg 活性プロセスと空孔型欠陥の研究”, 第 82 回応用物理学会秋季学術講演会, オンライン開催 (2021 年 9 月
21−23 日).
44. 嶋 紘平, 田中 亮, 高島信也, 上野勝典, 江戸雅晴, 小島一信, 上殿明良, 秩父重英，“空孔ガイド Mg 拡散法による p 型イオン注入 GaN の空間分解 CL 評価”, 第 82 回応用物理学会秋季
学術講演会, オンライン開催 (2021 年 9 月 21−23 日).
45. 佐々木泰祐, 宝野和博, 上殿明良, ” Mg 合金中のクラスター対相互作用による L12 クラスター
層の積層配列”, 日本金属学会 2021 年秋期（第 169 回）大会, オンライン開催(2021 年 9 月 14−17 日).
46. 角谷正友, 後藤 修,

Sang Liwen, 高原悠希, 上殿明良, 今中康貴, 今野泰一郎, 堀切文正,

木村健司, 藤倉序章, ”AlN/SiC テンプレート上にヘテロ成長した GaN-HEMT 構造の特性評
価”, 第 82 回応用物理学会秋季学術講演会, オンライン開催 (2021 年 9 月 10−13 日).
47. 喜多英治, 小野寺礼尚, 岸本幹雄, 柳原英人, “凍結した磁性流体のメスバウアー効果と磁気緩和”, 日本磁気学会講演会, オンライン開催 ( 2021 年 8 月 1 日−9 月 2 日).

61

7.4

UTTAC seminars

2021.11.24

Measurements of Higher-Order Cumulants of Net-Proton Distributions in 200 GeV p+p
Collisions at RHIC-STAR, Risa Nishitani (University of Tsukuba)

2021.12.21

Development of Time-of-Flight detector MRPC for J-PARC E16 experiment andperformance evaluation with 30 GeV proton beam in J-PARC, Shono Kyan (Universityof Tsukuba)

2021.12.21

Measurement of multiplicity dependence of electrons from beauty-hadron decay in pp and
p-Pb collisions at √𝑠= 5.02 TeV with LHC-ALICE, Shunya Chiba (University ofTsukuba)
2021.12.21

Measurement of transverse momentum and multiplicity dependence of heavy-flavor jets
production in pp collisions at √𝑠 = 13 TeV with LHC-ALICE, Momo Eshita (Universityof Tsukuba)

2022.1.11

Identification of quark and gluon jets by machine learning in pp collisions at √𝑠 = 13 TeV
with LHC-ALICE, Shuto Okada (University of Tsukuba)

2022.1.11

Measurement of neutral mesons inside jets in pp collisions at √𝑠 = 13 TeV with ALICEat the LHC, Hanseo Park (University of Tsukuba)

2022.1.11

Measurements of directed flow at forward and central rapidity region in 400AMeV
Xe + CsI collisions in HIMAC H447 experiment, Hidaka Tanabe (University of Tsukuba)

2022.1.11

Development of the RI beam position detector using the time-of-flight difference of
secondary electrons emitted from a thin foil, Naoto Kaname (University of Tsukuba)

62

8.
THESES

Photo by N. Shimada

From the “real” backyard of UTTAC

This stray cat, sitting beside Tajima-san, lives maybe
in the forest area adjacent to the UTTAC facility.

Doctor thesis
Yuki Sugisawa

Development of ERDA and NRA for light element depth profile in functional
thin films (機能性薄膜中軽元素の深さ分布測定に向けた ERDA および
NRA の開発)

Master theses
Naoto Kaname

Development of the RI beam position detector using the time-of-flightdifference of secondary electrons emitted from a thin foil (薄膜から放出される二次電子の飛行時間差を用いた RI ビーム位置検出器の開発)

Yurika Otani

Evaluation of oxide ion conduction properties in a solid oxide fuel cell material
Y2O3-stabilized ZrO2 with short-lived nucleus 19O (短寿命核 19O を用いた
固体酸化物形燃料電池材料 Y2O3 安定化 ZrO2 中における酸化物イオン
伝導特性の評価)

Takuro Narita

Characterization of vacancy-type defects in high-κ HfO2 using positronannihilation spectroscopy (陽電子消滅法を用いた High-κ 材料 HfO2 の空孔型欠陥評価)Kouya Nitta

Characterization of free volume in fatigued CFRP using positronannihilation spectroscopy (陽電子消滅法を用いた疲労 CFRP の自由体積評価)

Kiyoshi Yoshimura

Characterization of vacancy-type defects in AlN using positron annihilation
spectroscopy (陽電子消滅法を用いた AlN の空孔型欠陥評価)

Natsuko Kishi

Development of Auger electron spectrometer under ion channeling condition(チャネリング・オージェ電子観察に向けた電子分光器の開発)

Undergraduate theses
Atsuyuki Moriyama

Search for ejectile ions from arc plasma source (アークプラズマ蒸着源からの出射イオンの探索)

Maruko Hiraga

Development of beam current monitoring system for the 0-degree electron
spectroscopy (0°電子分光用ビームカレントモニターの製作)

Yutaro Suzuki

Development of analyzing methods for the depth-profiling of hydrogen usingtransmission ERDA (透過型 ERDA における水素の深さ分布解析手法の開発)

Kazuma Torii

Characterization of vacancy-type defects in N- and Mg-implanted GaN using
positron annihilation spectroscopy (陽電子消滅法を用いた N と Mg 注入
GaN の空孔型欠陥の評価)

63

Ryu Hioki

Characterization of vacancy-type defects in high-pressure-annealed p-type
GaN implanted with Mg using positron annihilation spectroscopy (陽電子消滅法を用いた超高圧アニールによる Mg イオン注入 p 型 GaN の空孔型
欠陥評価)

Kouta Homma

Characterization of free volume in fatigued CFRP using positron annihilation
spectroscopy (陽電子消滅法を用いた CFRP 疲労試験材の自由体積評価)

Ryosuke Miura

Characterization of vacancy-type defects in high-κ gate-insulating films of
HfO2 using positron annihilation spectroscopy (陽 電 子 消 滅 法 を 用 い た
High-κゲート絶縁膜 HfO2 の空孔型欠陥評価)

Chihiro Kodaka

Crystal structure and magnetic properties of FeCo nitride fine particles
synthesized by ammonia nitrification (アンモニア導入により作製した
FeCo 窒化物微粒子の結晶構造と磁気特性)64

9.
LIST OF PERSONNEL

Commemorating the retirement of engineer Mr. Tajima (center)
after his 47-year contribution to UTTAC.

Tandem Accelerator Complex
A. Uedono

Director, Professor

K. Sasa

Associate Professor

D. Sekiba

Lecturer

T. Moriguchi

Assistant Professor

Y. Tajima

Mechanical Engineer

S. Ishii

Mechanical Engineer

T. Takahashi

Electrical Engineer

Y. YamatoElectrical Engineer

M. Matsumura

Technical Staff

S. Kuramochi

Administrative Staff

N. Shimada

Administrative Staff

H. Muromachi

Administrative Staff

Research Members1
Department of Physics
A. Ozawa

K. Sasa

T. Moriguchi

T. Yamaguchi (Saitama University [Cross appointment])
Department of Applied Physics
A. Uedono

H. Yanagihara

H. Tanimoto

S. Tomita

D. Sekiba

S. Sharmin

E. Kita

Department of Geoscience
M. Kurosawa
Department of Biology
I. Suzuki
Department of Chemistry
K. Sueki

A. Sakaguchi

Department 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.
65

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])
Graduate students
Y. Sugisawa

T. Ikeda

N. Kaname

H. Koizumi

D. Hirose

N. Kishi

T. Okamoto

S. Hatada

A. YanoY. YueA. Inoue

T. Yang

K. Nishizuka

Y. GaoZ. ShiD. Shiine

T. Nakamura

K. Sakakura

N. Takahashi

S. Oshida

Y. Suzuki

M. Hiraga

A. Moriyama

R. Tanaka

R. Takatsuki

Y. Kurihara

H. Yoshikado

K. Torii

K. Homma

R. Hioki

R. Miura

Undergraduates

External users and collaborators
Y. Iwata

National Institute of Advanced Industrial Science and Technology (AIST)

K. Tomita

National Institute of Advanced Industrial Science and Technology (AIST)

S. Shiki

National Institute of Advanced Industrial Science and Technology (AIST)

T. Ishizuka

National Institute of Advanced Industrial Science and Technology (AIST)

H. Matsui

National Institute of Advanced Industrial Science and Technology (AIST)

T. Matsunaka

Kanazawa University

M. Honda

Japan Atomic Energy Agency (JAEA)

M. Mihara

Osaka University

Y. Otani

Osaka University

Y. Kimura

Osaka University

G. Takayama

Osaka University

M. Fukutome

Osaka University

T. Sugisaki

Osaka University

R. UdaOsaka University

H. Yuta

Osaka University

T. Suzuki

Saitama University

M. Otsu

Saitama University

N. Shinozaki

Saitama University

M. Kanda

Saitama University

H. Seki

Saitama University

66

S. Harayama

Saitama University

K. Sasaki

Saitama University

S. Matsuda

Saitama University

K. Okubo

Saitama University

S. Sugimoto

Saitama University

Y. Koizumi

Saitama University

A. Yanai

Saitama University

T. Hitosugi

Tokyo Institute of Technology

R. Shimizu

Tokyo Institute of Technology

S. Kobayashi

Tokyo Institute of Technology

H. Matsumura

High Energy Accelerator Research Organization (KEK)

G. YoshidaHigh Energy Accelerator Research Organization (KEK)

H. Nakamura

High Energy Accelerator Research Organization (KEK)

A. Toyoda

High Energy Accelerator Research Organization (KEK)

T. MiuraHigh Energy Accelerator Research Organization (KEK)67