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Sans-Planell, O.*; Shinohara, Takenao; Grazzi, F.*; Cantini, F.*; Su, Y. H.; Matsumoto, Yoshihiro*; Parker, J. D.*; Manke, I.*
Review of Scientific Instruments, 95(11), p.113702_1 - 113702_5, 2024/11
Matsumoto, Yoshihiro*; Oikawa, Kenichi; Watanabe, Kenichi*; Sato, Hirotaka*; Parker, J. D.*; Shinohara, Takenao; Kiyanagi, Yoshiaki*
Journal of Archaeological Science; Reports, 58, p.104729_1 - 104729_10, 2024/10
Higuchi, Yuki*; Yoshimune, Wataru*; Kato, Satoru*; Hibi, Shogo*; Setoyama, Daigo*; Isegawa, Kazuhisa*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Harada, Masashi*; et al.
Communications Engineering (Internet), 3, p.33_1 - 33_7, 2024/02
Nozaki, Hiroshi*; Kondo, Hiroki*; Shinohara, Takenao; Setoyama, Daigo*; Matsumoto, Yoshihiro*; Sasaki, Tsuyoshi*; Isegawa, Kazuhisa*; Hayashida, Hirotoshi*
Scientific Reports (Internet), 13, p.22082_1 - 22082_8, 2023/12
Times Cited Count：2 Percentile：29.93(Multidisciplinary Sciences)Yasuda, Yosuke*; Matsumoto, Yoshihiro*; Shinohara, Takenao; Nabeshima, Fumika*; Horiuchi, Keisuke*; Nagai, Hiroki*
International Journal of Heat and Mass Transfer, 213, p.124291_1 - 124291_2, 2023/10
Times Cited Count：0 Percentile：0.00(Thermodynamics)Yoshimune, Wataru*; Higuchi, Yuki*; Kato, Akihiko*; Hibi, Shogo*; Yamaguchi, Satoshi*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Shinohara, Takenao; Kato, Satoru*
ACS Energy Letters (Internet), 8(8), p.3485 - 3487, 2023/08
Times Cited Count：10 Percentile：82.89(Chemistry, Physical)Oba, Yojiro; Motokawa, Ryuhei; Kaneko, Koji; Nagai, Takayuki; Tsuchikawa, Yusuke; Shinohara, Takenao; Parker, J. D.*; Okamoto, Yoshihiro
Scientific Reports (Internet), 13, p.10071_1 - 10071_8, 2023/06
Times Cited Count：2 Percentile：65.72(Multidisciplinary Sciences)Isegawa, Kazuhisa; Setoyama, Daigo*; Higuchi, Yuki*; Matsumoto, Yoshihiro*; Nagai, Yasutaka*; Shinohara, Takenao
Nuclear Instruments and Methods in Physics Research A, 1040, p.167260_1 - 167260_10, 2022/10
Times Cited Count：3 Percentile：52.93(Instruments & Instrumentation)Murase, Kiyoka*; Kataoka, Ryuho*; Nishiyama, Takanori*; Nishimura, Koji*; Hashimoto, Taishi*; Tanaka, Yoshimasa*; Kadokura, Akira*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Ogawa, Yasunobu*; et al.
Journal of Space Weather and Space Climate (Internet), 12, p.18_1 - 18_16, 2022/06
Times Cited Count：1 Percentile：13.46(Astronomy & Astrophysics)We identified two energetic electron precipitation (EEP) events during the growth phase of moderate substorms and estimated the mesospheric ionization rate for an EEP event for which the most comprehensive dataset from ground-based and space-born instruments was available. The mesospheric ionization signature reached below 70 km altitude and continued for ~15 min until the substorm onset, as observed by the PANSY radar and imaging riometer at Syowa Station in the Antarctic region. We also used energetic electron flux observed by the Arase and POES 15 satellites as the input for the air-shower simulation code PHITS to quantitatively estimate the mesospheric ionization rate. Combining the cutting-edge observations and simulations, we shed new light on the space weather impact of the EEP events during geomagnetically quiet times, which is important to understand the possible link between the space environment and climate.
Kitagawa, Yoshihiro; Shirahama, Takuma*; Kisohara, Naoyuki; Tsuboi, Akihiko
Dai-96-Kai Reza Kako Gakkai Koen Rombunshu (Internet), p.91 - 96, 2022/01
Laser scanning quenching is a locally and rapidly heat-treated process and has an advantage of no coolant required. Compared with conventional technique such as induction quenching, the region of laser quenching is about 0.5
0.7mm in depth and it needs to be expanded for more applications or durability. For this purpose, the temperature distributions and transitions in materials during laser irradiation have been revealed by using a 3D heat transfer computer code, micro-structural observation and hardness transitions in depth direction. The results indicate the laser irradiation with low power and low scan speed condition allows deeper quenching area, but it also suggests the hardness of the deepest quenching area is degraded due to slow temperature decreasing rate after laser heat scanning. Multiple times continuous irradiation have been proposed and studied to resolve this hardness degradation, and maximum quenching depth of 1.4mm is obtained under three times irradiation and controlling its power and scan speed properly.
Abe, Yuta; Tsuchikawa, Yusuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Parker, J. D.*; Shinohara, Takenao; Oishi, Yuji*; Kamiyama, Takashi*; Nagae, Yuji; Sato, Ikken
JPS Conference Proceedings (Internet), 33, p.011075_1 - 011075_6, 2021/03
Tsuchikawa, Yusuke; Abe, Yuta; Oishi, Yuji*; Kai, Tetsuya; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Kimura, Atsushi; Nakamura, Shoji; Harada, Masahide; et al.
JPS Conference Proceedings (Internet), 33, p.011074_1 - 011074_6, 2021/03
In the decommissioning of the Fukushima-Daiichi (1F) Nuclear Power Plant, it is essential to understand characteristics of the melted core materials. The estimation of boride in the real debris is of great importance to develop safe debris removal plans. Hence, it is required to investigate the amount of boron in the melted core materials with nondestructive methods. Prompt gamma-ray activation analysis (PGAA) is one of the useful techniques to determine the amount of borides by means of the 478 keV prompt gamma-ray from neutron absorption reaction of boron. Moreover, it is well known that the width of the 478 keV gamma-ray peak is typically broadened due to the Doppler effect. The degree of the broadening is affected by coexisting materials, and can be recognized by the width of the prompt gamma-ray peak. As a feasibility study, the prompt gamma-ray from boride samples were measured using the ANNRI, NOBORU, and RADEN beamlines at the Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Complex (J-PARC).
Higuchi, Yuki*; Setoyama, Daigo*; Isegawa, Kazuhisa; Tsuchikawa, Yusuke; Matsumoto, Yoshihiro*; Parker, J. D.*; Shinohara, Takenao; Nagai, Yasutaka*
Physical Chemistry Chemical Physics, 23(2), p.1062 - 1071, 2021/01
Times Cited Count：10 Percentile：64.44(Chemistry, Physical)This study is the first report on liquid water and ice imaging conducted at a pulsed spallation neutron source facility. Neutron imaging can be utilised to visualise the water distribution inside polymer electrolyte fuel cells (PEFCs). Particularly, energy-resolved neutron imaging is a methodology capable of distinguishing between liquid water and ice, and is effective for investigating ice formation in PEFCs operating in a subfreezing environment. The distinction principle is based on the fact that the cross sections of liquid water and ice differ from each other at low neutron energies. In order to quantitatively observe transient freezing and thawing phenomena in a multiphase mixture (gas/liquid/solid) within real PEFCs with high spatial resolution, a pulsed neutron beam with both high intensity and wide energy range is most appropriate. In the validation study of the present work, we used water sealed in narrow capillary tubes to simulate the flow channels of a PEFC, and a pulsed neutron beam was applied to distinguish ice, liquid water and super-cooled water, and to clarify freezing and thawing phenomena of the water within the capillary tubes. Moreover, we have enabled the observation of liquid water/ice distributions in a large field of view (300 mm 
300 mm) by manufacturing a sub-zero environment chamber that can be cooled down to -30
C, as a step towards 
visualisation of full-size fuel cells.
Abe, Yuta; Tsuchikawa, Yusuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Parker, J. D.*; Shinohara, Takenao; Oishi, Yuji*; Kamiyama, Takashi*; Nagae, Yuji; Sato, Ikken
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 6 Pages, 2020/08
Parker, J. D.*; Harada, Masahide; Hayashida, Hirotoshi*; Hiroi, Kosuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Nakatani, Takeshi; Oikawa, Kenichi; Segawa, Mariko; Shinohara, Takenao; et al.
Materials Research Proceedings, Vol.15, p.102 - 107, 2020/05
Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi; Nakatani, Takeshi; Segawa, Mariko; Hiroi, Kosuke; Su, Y. H.; Oi, Motoki; Harada, Masahide; Iikura, Hiroshi; et al.
Review of Scientific Instruments, 91(4), p.043302_1 - 043302_20, 2020/04
Times Cited Count：61 Percentile：96.75(Instruments & Instrumentation)Kai, Tetsuya; Shinohara, Takenao; Matsumoto, Yoshihiro*
Kensa Gijutsu, 25(2), p.1 - 5, 2020/02
no abstracts in English
Oikawa, Kenichi; Kiyanagi, Yoshiaki*; Sato, Hirotaka*; Omae, Kazuma*; Pham, A.*; Watanabe, Kenichi*; Matsumoto, Yoshihiro*; Shinohara, Takenao; Kai, Tetsuya; Harjo, S.; et al.
Materials Research Proceedings, Vol.15, p.207 - 213, 2020/02
Kai, Tetsuya; Hiroi, Kosuke; Su, Y. H.; Segawa, Mariko; Shinohara, Takenao; Matsumoto, Yoshihiro*; Parker, J. D.*; Hayashida, Hirotoshi*; Oikawa, Kenichi
Materials Research Proceedings, Vol.15, p.149 - 153, 2020/02
Shoji, Eita*; Isogai, Shosei*; Suzuki, Rikuto*; Kubo, Masaki*; Tsukada, Takao*; Kai, Tetsuya; Shinohara, Takenao; Matsumoto, Yoshihiro*; Fukuyama, Hiroyuki*
Scripta Materialia, 175, p.29 - 32, 2020/01
Times Cited Count：22 Percentile：77.34(Nanoscience & Nanotechnology)