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Np and 
Am gamma ray regionsFukuda, Tatsuo; Kobata, Masaaki; Shobu, Takahisa; Yoshii, Kenji; Kamiya, Junichiro; Iwamoto, Yosuke; Makino, Takahiro*; Yamazaki, Yuichi*; Oshima, Takeshi*; Shirai, Yasuhiro*; et al.
Journal of Applied Physics, 132(24), p.245102_1 - 245102_8, 2022/12
Times Cited Count：1 Percentile：14.73(Physics, Applied)Direct energy conversion has been investigated using Ni/SiC Schottky junctions with the irradiation of monochromatized synchrotron X-rays simulating the gamma rays of Np (30 keV) and Am (60 keV). From current-voltage measurements, electrical energies were obtained for both kinds of gamma rays. The energy conversion efficiencies were found to reach up to 
1.6%, which is comparable to those of a few other semiconducting systems reported thus far. This result shows a possibility of energy recovery from nuclear wastes using the present system, judging from the radiation tolerant nature of SiC. Also, we found different conversion efficiencies between the two samples. This could be understandable from hard X-ray photoelectron spectroscopy and secondary ion mass spectroscopy measurements, suggesting the formation of Ni-Si compounds at the interface in the sample with a poor performance. Hence, such combined measurements are useful to provide information that cannot be obtained by electrical measurements alone.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：44 Percentile：96.99(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.
Science, 364(6437), p.272 - 275, 2019/04
Times Cited Count：262 Percentile：99.73(Multidisciplinary Sciences)The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Tabata, Tatsuo*; Shirai, Toshizo*; Sataka, Masao; Kubo, Hirotaka
Atomic Data and Nuclear Data Tables, 92(3), p.375 - 406, 2006/05
Times Cited Count：73 Percentile：95.09(Physics, Atomic, Molecular & Chemical)no abstracts in English
HfNCl superconductors with 
=22 KShamoto, Shinichi; Hirai, Atsuo*; Yamanaka, Shoji*; Aso, Naofumi*; Kajitani, Tsuyoshi*
Journal of Neutron Research, 12(4), p.295 - 300, 2004/12
Inelastic neutron scattering measurements have been performed on superconducting NaHfNCl powder samples with x=0.27 and 0.38 (T =22 K). We have observed several temperature dependent phonon anomalies, e.g., at E=15, 29, 76, and 81 meV for the former sample. A phonon peak with E=14.5 meV at Q=6 
increases for both samples with decreasing temperature below T=40 K, which is much higher than T. The phonon peak is assigned to an ab-plane vibrational mode, E
, of chlorine and hafnium atoms, which strongly modifies the electronic band structure. The phonon anomaly is discussed in terms of carrier inhomogeneity.
Kamada, Yutaka; Fujita, Takaaki; Ishida, Shinichi; Kikuchi, Mitsuru; Ide, Shunsuke; Takizuka, Tomonori; Shirai, Hiroshi; Koide, Yoshihiko; Fukuda, Takeshi; Hosogane, Nobuyuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.185 - 254, 2002/09
Times Cited Count：34 Percentile：48.48(Nuclear Science & Technology)With the main aim of providing physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has been developing and optimizing the operational concepts, and extending the discharge regimes toward sustainment of high integrated performance in the reactor relevant parameter regime. In addition to achievement of the equivalent break-even condition (QDTeq up to 1.25) and a high fusion triple product = 1.5E21 m-3skeV, JT-60U has demonstrated the integrated performance of high confinement, high beta-N, full non-inductive current drive with a large fraction of bootstrap current in the reversed magnetic shear and in the high-beta-p ELMy H mode plasmas characterized by both internal and edge transport barriers. The key factors in optimizing these plasmas are profile and shape controls. As represented by discovery of various Internal Transport Barriers, JT-60/JT-60U has been emphasizing freedom and restriction of profiles in various confinement modes. JT-60U has demonstrated applicability of these high confinement modes to ITER and also clarified remaining issues.
, C
H
, CH, CH, C
H
, and CHShirai, Toshizo; Tabata, Tatsuo*; Tawara, Hiroyuki*; Ichikawa, Yukikazu*
Atomic Data and Nuclear Data Tables, 80(2), p.147 - 204, 2002/03
Times Cited Count：74 Percentile：93.79(Physics, Atomic, Molecular & Chemical)Cross sections for 138 processes of hydrocarbons in collisions with electrons, based on available literature sources, are critically compiled. The leterature has been surveyed to September 2000. A short comment is given for each measurement. The recommended data sets are presented in separate graphs for each process. Analytic fits to the recommended cross sections are also presented.
, and HO relevant to edge plasma impuritiesShirai, Toshizo; Tabata, Tatsuo*; Tawara, Hiroyuki*
Atomic Data and Nuclear Data Tables, 79(1), p.143 - 184, 2001/09
Times Cited Count：56 Percentile：91.40(Physics, Atomic, Molecular & Chemical)no abstracts in English
Kubo, Hirotaka; Sakurai, Shinji; Asakura, Nobuyuki; Konoshima, Shigeru; Tamai, Hiroshi; Higashijima, Satoru; Sakasai, Akira; Takenaga, Hidenobu; Itami, Kiyoshi; Shimizu, Katsuhiro; et al.
Nuclear Fusion, 41(2), p.227 - 233, 2001/02
Times Cited Count：53 Percentile：81.48(Physics, Fluids & Plasmas)no abstracts in English
, H
, H
, H, H and H
with hydrogen moleculesTabata, Tatsuo*; Shirai, Toshizo
Atomic Data and Nuclear Data Tables, 76(1), p.1 - 25, 2000/09
Times Cited Count：79 Percentile：94.45(Physics, Atomic, Molecular & Chemical)no abstracts in English
Suzuki, Shingo*; Shimizu, Katsuhiro; Kubo, Hirotaka; Shirai, Toshizo; Sakasai, Akira; Sugie, Tatsuo; Asakura, Nobuyuki
Europhysics Conference Abstracts, 23J, p.477 - 480, 1999/00
no abstracts in English
Asakura, Nobuyuki; Hosogane, Nobuyuki; Itami, Kiyoshi; Sakasai, Akira; Sakurai, Shinji; Shimada, Michiya; Kubo, Hirotaka; Higashijima, Satoru; Shimizu, Katsuhiro; Takenaga, Hidenobu; et al.
Journal of Nuclear Materials, 266-269, p.182 - 188, 1999/00
Times Cited Count：66 Percentile：96.64(Materials Science, Multidisciplinary)no abstracts in English
Suzuki, Shingo*; Shirai, Toshizo; Nemoto, Masahiro; Tobita, Kenji; Kubo, Hirotaka; Sugie, Tatsuo; Sakasai, Akira; Kusama, Yoshinori
Plasma Physics and Controlled Fusion, 40(12), p.2097 - 2111, 1998/00
Times Cited Count：61 Percentile：85.55(Physics, Fluids & Plasmas)no abstracts in English
, He and Li atoms and ions with atoms and molecules,IVIto, Rinsuke*; Tabata, Tatsuo*; Shirai, Toshizo; R.A.Phaneuf*
JAERI-Data/Code 96-024, 62 Pages, 1996/07
JAERI-Data-Code-96-024.pdf:1.32MB
no abstracts in English
, He and Li atoms and ions with atoms and molecules, IIIIto, Rinsuke*; Tabata, Tatsuo*; Shirai, Toshizo; R.A.Phaneuf*
JAERI-Data/Code 95-008, 71 Pages, 1995/07
JAERI-Data-Code-95-008.pdf:1.54MB
no abstracts in English
Shirai, Hiroshi; Takizuka, Tomonori; Kikuchi, Mitsuru; Mori, Masahiro; Nishitani, Takeo; Ishida, Shinichi; Kamada, Yutaka; Sato, Masayasu; Isei, Nobuaki; Koide, Yoshihiko; et al.
IAEA-CN-60/A2-17, 0, p.355 - 364, 1995/00
no abstracts in English
, He and Li atoms and ions with atoms and molecules, IIIto, Rinsuke*; Tabata, Tatsuo*; Shirai, Toshizo; R.A.Phaneuf*
JAERI-Data/Code 94-005, 94 Pages, 1994/07
JAERI-Data-Code-94-005.pdf:2.0MB
no abstracts in English
Futakawa, Masatoshi; Iyoku, Tatsuo; Shirai, Hiroshi*; Takada, Shoji; Ishihara, Masahiro
Nucl. Eng. Des., 148, p.83 - 90, 1994/00
Times Cited Count：4 Percentile：42.28(Nuclear Science & Technology)no abstracts in English
Shirai, Hiroshi; Hirayama, Toshio; Koide, Yoshihiko; Yoshida, Hidetoshi; Naito, Osamu; Sato, Masayasu; Fukuda, Takeshi; Sugie, Tatsuo; Azumi, Masafumi; D.R.Mikkelsen*; et al.
Nuclear Fusion, 34(5), p.703 - 727, 1994/00
Times Cited Count：7 Percentile：31.14(Physics, Fluids & Plasmas)no abstracts in English
, He and Li atoms and ions with atoms and molecules, IIto, Rinsuke*; Tabata, Tatsuo*; Shirai, Toshizo; R.A.Phaneuf*
JAERI-M 93-117, 91 Pages, 1993/06
no abstracts in English
