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Saito, Yuki*; Ishiwata, Tobimaru*; Horiuchi, Misato*; Nishiki, Yuto*; Kikuchi, Ryosuke*; Otake, Tsubasa*; Kawakita, Ryohei; Takayama, Yusuke; Mitsui, Seiichiro; Sato, Tsutomu*
Shigen, Sozai Koenshu (Internet), 11(1), 7 Pages, 2024/03
no abstracts in English
-base GdO
precipitations in a Mg-Zn-Gd alloyIto, Yuto*; Egusa, Daisuke*; Yamaguchi, Masatake; Abe, Eiji*
Materials Transactions, 64(8), p.2022 - 2025, 2023/08
Times Cited Count：0 Percentile：0(Materials Science, Multidisciplinary)We have found that, during 
scanning transmission electron microscopy observations, heating of a Mg
Zn
Gd
(at.%) alloy at 623K leads to dynamic precipitations of face-centered-cubic ()-based Gd nanoparticles. With the aid of density-functional theory (DFT) calculations, the observed lattice constant of 5.32
, which is larger than that expected for pure -Gd of 5.06, is likely to be due to oxygen atoms inserted at tetrahedral interstitial sites with essentially a fractional occupation. Systematic DFT calculations show possible occurrences of -Gd-based oxide phase with a wide non-stoichiometry range by occupying either tetrahedral or octahedral interstitial positions, being represented as GdO.
-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samplesLi, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count：4 Percentile：29.37(Chemistry, Analytical)no abstracts in English
Machida, Masahiko; Shi, W.*; Yamada, Susumu; Miyamura, Hiroko; Yoshida, Toru*; Hasegawa, Yukihiro*; Okamoto, Koji; Aoki, Yuto; Ito, Rintaro; Yamaguchi, Takashi; et al.
Proceedings of Waste Management Symposia 2023 (WM2023) (Internet), 11 Pages, 2023/02
Fujiyama, Hiroki*; Takahashi, Hiroki; Okabe, Kota; Ito, Yuichi*; Hatakeyama, Shuichiro; Suzuki, Takahiro*; Otsu, Satoru*; Yamakawa, Ryuto*
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.529 - 531, 2023/01
Stepper motors are used for mechanical drive in collimators and wire scanner monitors of J-PARC accelerators. Many of these drive unit hardware have been used since the beginning of J-PARC construction, and it is necessary to take measures against aging deterioration. Therefore, we started updating the motor and control system from around 2017. However, when the stepper motor was updated to the current product in the RCS H0 collimator, a malfunction occurred. This is because the drive unit control system cannot correctly recognize the state of the LS (limit switch) due to the noise generated by the motor driver, which hinders the operation. When the noise generated from the old and new stepper motors was measured in a simple test environment for confirmation, it was found that the current product was clearly larger. As a countermeasure, when the wiring of the stepper motor, which was bundled in a single multi-core cable, was separated into separate cables for the power system and LS signal system, the noise level was reduced to about 1/10 and normal operation was restored. I was able to. In this case, we report on noise countermeasures for the RCS H0 collimator drive unit.
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：6 Percentile：49.29(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
-ray irradiation facilitiesAgematsu, Takashi; Uno, Sadanori; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Yamasaki, Shota; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 173, 2016/02
The electron accelerator and the three -ray irradiation facilities of Takasaki Advanced Radiation Research Institute were operated for various research subjects according to the operation plan in FY 2014. The number of research subjects in FY 2014 decreased at the electron accelerator with operation stop by accelerator trouble, and increased slightly at the -ray irradiation facilities as compared with FY 2013, and research subjects were 205 and 857, respectively. Among these research subjects, 35 and 172 related to recovery from the Fukushima Daiichi Nuclear disaster, respectively, were performed at the electron accelerator and the -ray irradiation facilities, respectively.
Co -ray irradiation facilitiesUno, Sadanori; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Yamasaki, Shota; Agematsu, Takashi; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 172, 2016/02
This paper reports on the operation status of the -ray irradiation facilities and the electron accelerator in fiscal 2014 at the Takasaki Advanced Radiation Research Institute of JAEA. The -ray irradiation facilities were operated smoothly, whereas the electron accelerator stopped for five months because of successive troubles of discharge due to deterioration of equipment over thirty-four years. The annual operation times of the -ray irradiation facilities of the first, second and food buildings were 19,907, 13,831 and 7,293 hours, respectively, and that of the electron accelerator was 746 hours. The -ray irradiation facilities were replenished with new five sources of 2.22 PBq, and twenty old sources were removed for disposal. The electron accelerator was repaired for each trouble, however, the complete recovery has not yet been achieved.
Uno, Sadanori; Hanaya, Hiroaki; Yamasaki, Shota; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Agematsu, Takashi; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
Dai-28-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.121 - 123, 2015/12
no abstracts in English
-ray irradiation facilitiesAgematsu, Takashi; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 183, 2015/03
The electron accelerator and the three -ray irradiation facilities were operated for various research subjects according to the operation plan in FY 2013. The number of research subjects at the electron accelerator and at the -ray irradiation facilities kept constant from FY 2012. Among these research subjects, 47 and 91 ones respectively performed at the electron accelerator and the -ray irradiation facilities were relevant to recovery from the Fukushima Daiichi nuclear disaster.
-ray irradiation facilitiesAgematsu, Takashi; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 182, 2015/03
The electron accelerator and the -ray irradiation facility have been operated approximately smoothly. The annual operation time in FY 2013 for the electron accelerator, the first, the second cobalt irradiation facility and food irradiation facility are 1242 h, 18,900 h, 11,804 h and 6,587 h, respectively. Typically repairs were next ones. The SF
gas withdrawal system was renewed at the electron accelerator. The 600 m
water storage tank was installed to keep pool-water for the cobalt facilities maintenance. New pieces of Co sources were purchased and loaded to the first and the second irradiation facility. The maintenance check was done for the food irradiation facility.
-ray irradiation facilitiesAgematsu, Takashi; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 181, 2014/03
The electron accelerator and the three -ray irradiation facilities were operated for various research subjects according to the operation plan in FY 2012. The number of research subjects at the electron accelerator kept constant compared with FY 2011. The number of research subjects at the -ray irradiation facilities slightly decreased year after year. Of all these research subjects, 14 ones at the electron accelerator and 93 ones at the -ray irradiation facilities were relevant to the Fukushima Daiichi nuclear disaster.
-ray irradiation facilitiesAgematsu, Takashi; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 180, 2014/03
The electron accelerator and the -ray irradiation facility have been operated without serious trouble. The annual operation time in FY 2012 for the electron accelerator, the first, the second cobalt irradiation facility and food irradiation facility are 910 h, 15,738 h, 10,537 h and 7,871 h, respectively. Typicaly repairs were next ones. The SF6 gas withdrawal system broke of the accelerator, and there was trouble of mixing in of air. The maintenance check of the first irradiation facility was done. The Co ources were purchased and loaded to the first irradiation facility. Fifteen pencil sources of Co with length of 30 cm each, twelve ball sources of Co and five 
Cs source were disposed of, and they were transferred to Japan Radioisotope Association (JRIA).
-ray irradiation facilitiesAgematsu, Takashi; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 174, 2013/01
The electron accelerator and the -ray irradiation facility have been operated without serious trouble. The annual operation time in FY 2011 for the electron accelerator, the first, the second cobalt irradiation facility and food irradiation facility are 1,059 h, 18,722 h, 9,976 h and 7,427 h, respectively. Typically repairs were next ones. The beam control circuit trouble and the isolation trouble by mixing in of air into SF gas at electron accelerator were repaired. The maintenance check of the second irradiation facility was done. The Co sources were purchased and loaded to the second irradiation facility. Forty five pencil sources of Co with length of 30 cm each, eight coin sources of Co and the -ray radiographic apparatus with a Co source were disposed to Japan Radioisotope Association (JRIA).
-ray irradiation facilitiesHaruyama, Yasuyuki; Agematsu, Takashi; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 175, 2013/01
The electron accelerator and the three -ray irradiation facilities were operated for various research subjects according to the operation plan in FY 2011 without serious trouble. The number of research subjects at the electron accelerator increased in the research fields of nuclear facilities and resources & biotechnology, and decreased in the fields of material processing and material for space. The number of research subjects at the -ray irradiation facilities increased in the fields of material for space and material processing, and decreased in the fields of nuclear facilities and resources & biotechnology. Of all these research subjects, 15 ones at the electron accelerator and 94 ones at the -ray irradiation facilities were relevant to the Fukushima Daiichi nuclear disaster.
Seito, Hajime; Nagao, Yuto; Momoki, Yohei*; Kaneko, Hirohisa; Nakagawa, Kazumichi*; Kojima, Takuji
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 153, 2013/01
no abstracts in English
Odaka, Hirokazu*; Ichinohe, Yuto*; Takeda, Shinichiro*; Fukuyama, Taro*; Hagino, Koichi*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; Watanabe, Shin*; Kokubun, Motohide*; et al.
Nuclear Instruments and Methods in Physics Research A, 695, p.179 - 183, 2012/12
Times Cited Count：23 Percentile：83.88(Instruments & Instrumentation)We have developed a new Si/CdTe semiconductor double-sided strip detector (DSD) Compton camera. The camera consists of a 500-
m-thick Si-DSD and four layers of 750-m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 degrees at 356 keV and 3.5 degrees at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.
-ray cameraTakeda, Shinichiro*; Ichinohe, Yuto*; Hagino, Koichi*; Odaka, Hirokazu*; Yuasa, Takayuki*; Ishikawa, Shinnosuke*; Fukuyama, Taro*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; et al.
Physics Procedia, 37, p.859 - 866, 2012/10
Times Cited Count：23 Percentile：98.4(Physics, Applied)By using new Compton camera consisting of silicon double-sided strip detector (Si-DSD) and CdTe-DSD developed for the ASTRO-H mission, an experiment was conducted to study its feasibility for advanced hotspot monitoring. In addition to hotspot imaging already provided by commercial imaging systems, the identification of the variety of radioisotopes is realized thanks to the good energy resolution given by the semiconductor detectors. Three radioisotopes of 
Ba (356 keV), 
Na (511 keV) and Cs (662 keV) were individually imaged by applying event selection in the energy window and the -ray images was correctly overlapped by an optical picture. The detection efficiency of 1.68
10
(effective area: 1.710 cm
) and angular resolution of 3.8
were obtained by stacking five detector modules for 662 keV -ray. The higher detection efficiency required in a specific use can be achieved by stacking more detector modules.
Nagao, Yuto; Seito, Hajime; Momoki, Yohei*; Kaneko, Hirohisa; Nakagawa, Kazumichi*; Kojima, Takuji
Radioisotopes, 61(4), p.173 - 177, 2012/04
Applications of alanine dosimeter are widen to dosimetry in space environment and so on. The effect of temperature during and after irradiation between 20C and 80C on the dose response of alanine dosimeters was investigated under low dose of about 10 - 20 Gy and long time of about 100 hours irradiations. When a stable component of the dose response under high irradiation temperature is estimated on the basis of the effect of storage temperature after irradiation taking into account the known irradiation temperature coefficient, dose evaluation using alanine dosimeter should be more accurate even suffering from combined temperature effects during and after irradiation.
-ray irradiation facilitiesHaruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Kawashima, Ikuo*; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 174, 2012/01
The electron accelerator and -ray irradiation facilities have been operated without serious troubles before the earthquake happened in March 11 2011. The electron accelerator and -ray irradiation facilities were stopped with concern about the earthquake damage, for 13 and 20 days, respectively.
