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Shibata, Takanori*; Shinto, Katsuhiro; Nammo, Kesao*; Okoshi, Kiyonori; Ikegami, Kiyoshi*; Oguri, Hidetomo; Ishida, Masaki*; Wada, Motoi*
Journal of Instrumentation (Internet), 19(1), p.C01009_1 - C01009_8, 2024/01
Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)From Nov. 2020 to Apr. 2021, the continuous ion source operation for 3,651 hours (5 months) was achieved. As the lifetime of the RF ion source is mainly limited by failure on the enamel coating of the RF antenna, detailed evaluation of the antenna surface is required to ensure feasibility of the further extension of the operation time. In the present study, surface discoloration on the RF antenna coil observed after the 5 months operation is investigated by application of digital microscope and SEM/EDS analyses. The material mapping and the line spectrum obtained by the EDS analysis show that depositions of the sputtered source chamber wall materials and the injected cesium on to the enamel coating are the most possible candidate for the discoloration. The dimension measurements of the RF antenna thickness before and after the long-term operation support the idea that the discoloration is due to the deposited materials and hence insulation of the RF antenna coil by enamel coating is maintained. The emittance measurement after the operation also shows that the RF plasma and the beam formations are not affected by the deposition on the antenna.
Tsuji, Hayato*; Nakahata, Masaki*; Hishida, Mafumi*; Seto, Hideki*; Motokawa, Ryuhei; Inoue, Takeru*; Egawa, Yasunobu*
Journal of Physical Chemistry Letters (Internet), 14(49), p.11235 - 11241, 2023/12
Times Cited Count:15 Percentile:85.81(Chemistry, Physical)Otsuki, Daiki*; Ishida, Tatsuhiro*; Tsutsumi, Naoya*; Kobayashi, Masaki*; Inagaki, Kodai*; Yoshida, Teppei*; Takeda, Yukiharu; Fujimori, Shinichi; Yasui, Akira*; Kitagawa, Saiki*; et al.
Physical Review Materials (Internet), 7(12), p.124601_1 - 124601_6, 2023/12
Times Cited Count:2 Percentile:11.53(Materials Science, Multidisciplinary)Davies, S. J. C.*; Bolea-Alamanac, B.*; Endo, Kaori*; Yamamoto, Yu*; Yamasaki, Shudo*; Malins, A.; Evans, J.*; Sullivan, S.*; Ando, Shuntaro*; Nishida, Atsushi*; et al.
Journal of Transport & Health, 28, p.101564_1 - 101564_11, 2023/01
Shibata, Takanori*; Ishida, Masaki*; Nammo, Kesao*; Ikegami, Kiyoshi*; Okoshi, Kiyonori; Shinto, Katsuhiro; Oguri, Hidetomo
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.863 - 867, 2023/01
Continuous operation duration of the J-PARC Radio Frequency (RF) ion source has been extended step by step these years for the goal to supply stable beam during the entire period of J-PARC user operation (around 7 months) each year. A 3651 hours (5 months) continuous ion source operation has been achieved from Nov. 2020 to Apr. 2021. As the lifetime of the ion source is mainly limited by failure on the RF antenna coil, detailed evaluation of the antenna surface condition is required to ensure the feasibility of the further extension of the operation time. In the present study, dimension measurements and SEM/EDS analyses were applied to understand the surface discoloration of the RF antenna. The discoloration after the long-term continuous operation is due to deposition of injected cesium (for H
surface production process) and of stainless used steel (Fe, Cr, Ni) from the ion source components sputtered by plasma. The results show that the enamel coating of the RF antenna has not worn out in the long-term continuous operation for several months and, hence, extension of the ion source continuous operation duration can be extended.
layers in the triple-layer cuprate Bi
Sr
Ca
Cu
O
studied by angle-resolved photoemission spectroscopyIdeta, Shinichiro*; Johnston, S.*; Yoshida, Teppei*; Tanaka, Kiyohisa*; Mori, Michiyasu; Anzai, Hiroaki*; Ino, Akihiro*; Arita, Masashi*; Namatame, Hirofumi*; Taniguchi, Masaki*; et al.
Physical Review Letters, 127(21), p.217004_1 - 217004_6, 2021/11
Times Cited Count:18 Percentile:74.56(Physics, Multidisciplinary)Sasaki, Hirokazu*; Nishikubo, Hideo*; Nishida, Shinsuke*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Isomatsu, Takemi*; Minato, Ryuichiro*; Kinugawa, Kohei*; Imamura, Akihiro*; Otomo, Shinya*; et al.
Furukawa Denko Jiho, (138), p.2 - 10, 2019/02
no abstracts in English
Torii, Tatsuo; Sanada, Yukihisa; Sugita, Takeshi; Kondo, Atsuya*; Shikaze, Yoshiaki; Takahashi, Masaki; Ishida, Mutsushi; Nishizawa, Yukiyasu; Urabe, Yoshimi
JAEA-Technology 2012-036, 182 Pages, 2012/12
We carried out aerial radiation monitoring (ARM) of all Japan area in order to investigate the influence of the radio cesium which was emitted into the atmosphere by disaster of the Fukushima Dai-ichi Nuclear Power Plant of Tokyo Electric Power Co., Inc.. AMS can measure a
ray quickly by flight from 300 m height above the ground. Moreover, ARM has an advantage which can grasp self-possessed quantity distribution of an air dose rate and radioactive cesium in "field", and is visually intelligible. Although there were apparatus and the technique of ARM in our country, sufficient preparations for wide area monitoring were not made. Therefore, it fixed based on the method of the U.S. Department of Energy (DOE) about the method of the conversion to all radiation dose, and the conversion method to radiocesium deposition and the method of mapping. It is possible to discriminate from a background (cosmic-ray, self-contamination and natural nuclides) at the time of western-part-of-Japan measurement by improving of the method in parallel to data acquisition. By this monitoring, it was able to check about the distribution situation of the air dose rate of the Japanese whole region, or the radioactive cesium deposition. Here, the measurement technique and a result are described.
Mizuta, Yoshio*; Hosokai, Tomonao*; Masuda, Shinichi*; Zhidkov, A.*; Makito, Keigo*; Nakanii, Nobuhiko*; Kajino, Shohei*; Nishida, Akinori*; Kando, Masaki; Mori, Michiaki; et al.
Physical Review Special Topics; Accelerators and Beams, 15(12), p.121301_1 - 121301_10, 2012/12
Times Cited Count:21 Percentile:69.69(Physics, Nuclear)Shinto, Katsuhiro; Wada, Motoi*; Nishida, Tomoaki*; Demura, Yasuhiro*; Sasaki, Daichi*; Tsumori, Katsuyoshi*; Nishiura, Masaki*; Kaneko, Osamu*; Kisaki, Masashi*; Sasao, Mamiko*
AIP Conference Proceedings 1390, p.675 - 683, 2011/09
Times Cited Count:0 Percentile:0.00(Physics, Atomic, Molecular & Chemical)
Co
OKobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Osafune, Yoshitaka*; Fujimori, Atsushi*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke*; Saeki, Hiromasa*; et al.
Physical Review B, 81(7), p.075204_1 - 075204_7, 2010/02
Times Cited Count:19 Percentile:59.57(Materials Science, Multidisciplinary)
orbitals in the oxide-based diluted magnetic semiconductor In
V
O
Kobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Song, G. S.*; Takizawa, Masaru*; Fujimori, Atsushi; Takeda, Yukiharu; Okochi, Takuo*; Okane, Tetsuo; Saito, Yuji; et al.
Physical Review B, 79(20), p.205203_1 - 205203_5, 2009/05
Times Cited Count:7 Percentile:31.42(Materials Science, Multidisciplinary)Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.
Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12
Times Cited Count:19 Percentile:73.43(Nuclear Science & Technology)no abstracts in English
transition edge sensorOkayasu, Satoru; Katagiri, Masaki; Hojo, Kiichi; Morii, Yukio; Miki, Shigenobu*; Shimakage, Hisashi*; Wang, Z.*; Ishida, Takekazu*
Physica C, 468(15-20), p.1998 - 2000, 2008/09
Times Cited Count:0 Percentile:0.00(Physics, Applied)We have been investigating for neutron detection with the MgB
transition edge sensor (TES). For the purpose, we have been developing a low noise measurement system for neutron detection. To confirm the usefulness of our detecting system, alpha-ray detection from an
Am source was achieved. To improve the sensitivity, short meander samples with 35
m length and 1
m width is used. Samples are fabricated by the Kansai group. Superconducting transition temperature Tc is 23.3 K. The transition width is sharp enough less than 1 K. The detection was achieved under a constant current condition, and the resistivity changes at the sample due to the alpha-ray irradiation were detected. The bias current is 6
A.
thin film detector for neutronsIshida, Takekazu*; Nishikawa, Masatoshi*; Fujita, Yoshifumi*; Okayasu, Satoru; Katagiri, Masaki*; Sato, Kazuo*; Yotsuya, Tsutomu*; Shimakage, Hisashi*; Miki, Shigehito*; Wang, Z.*; et al.
Journal of Low Temperature Physics, 151(3-4), p.1074 - 1079, 2008/05
Times Cited Count:40 Percentile:78.78(Physics, Applied)The superconducting neutron detector using high-quality
B-enriched MgB
thin films at higher operating temperatures has been proposed, where a resistance change induced by the nuclear reaction of neutron and
B in MgB
is used to detect a neutron. Cold neutrons from a nuclear research reactor irradiated the MgB
detector, and the output voltage was clearly observed through a low-noise amplifier by using a digital oscilloscope. The out-of-equilibrium thermodynamics was investigated by means of the time-dependent Ginzburg-Landau equations by using the Earth Simulator.
Cr
TeKobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Song, G. S.*; Fujimori, Atsushi; Yang, C. S.*; Lee, L.*; Lin, H.-J.*; Huang, D.-J.*; Chen, C. T.*; et al.
New Journal of Physics (Internet), 10, p.055011_1 - 055011_15, 2008/05
Times Cited Count:16 Percentile:64.46(Physics, Multidisciplinary)
Re by proton bombardment of enriched
WIimura, Hideki; Horiguchi, Takayoshi*; Ishida, Yoshihisa*; Ito, Mitsuo; Koizumi, Mitsuo; Miyabe, Masabumi; Oba, Masaki
Journal of the Physical Society of Japan, 77(2), p.025004_1 - 025004_2, 2008/02
Times Cited Count:2 Percentile:19.56(Physics, Multidisciplinary)The nucleus
Re is of interest from the astrophysical point of view, since production of this nucleus in stars could change an accuracy of nucleo-cosmochronometer. In order to calculate the neutron capture cross section theoretically, it is necessary to know the spin of nucleus. However, the spin of
Re has not been established so far. In order to clarify the nuclear structure of this nucleus, we plan laser spectroscopy of
Re, and first, we measured the production yield of the (
) reaction. The experiment was carried out by irradiating a
W target with a proton beam from the JAEA tandem accelerator. Rhenium was chemically separated from the irradiated sample, and then
-ray measurements were performed. As a result, we determined the production yield of the
W(
)
Re reaction for the first time and suggested the same spin for
Re as the known spin of
=8 for
Re.
Sr
CuO
revealed by
SRIshida, Kenji*; Higemoto, Wataru; Oishi, Kazuki; Koda, Akihiro*; Sato, Koki*; Kadono, Ryosuke*; Fujita, Masaki*; Yamada, Kazuyoshi*
Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.526 - 528, 2007/10
Times Cited Count:5 Percentile:25.86(Materials Science, Multidisciplinary)
V
O thin filmIshida, Yukiaki*; Hwang, J. I.*; Kobayashi, Masaki*; Takeda, Yukiharu; Mamiya, Kazutoshi*; Okamoto, Jun*; Fujimori, Shinichi; Okane, Tetsuo; Terai, Kota*; Saito, Yuji; et al.
Applied Physics Letters, 90(2), p.022510_1 - 022510_3, 2007/01
Times Cited Count:24 Percentile:63.98(Physics, Applied)no abstracts in English
Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.
Nuclear Fusion, 46(3), p.S29 - S38, 2006/03
Times Cited Count:13 Percentile:39.83(Physics, Fluids & Plasmas)The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.