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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：97.1(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.
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
Theis, C.*; Carbonez, P.*; Feldbaumer, E.*; Forkel-Wirth, D.*; Jaegerhofer, L.*; Pangallo, M.*; Perrin, D.*; Urscheler, C.*; Roesler, S.*; Vincke, H.*; et al.
EPJ Web of Conferences, 153, p.08018_1 - 08018_5, 2017/09
Times Cited Count：0 Percentile：0.03(Nuclear Science & Technology)At CERN, gas-filled ionization chambers PTW-34031 (PMI) are commonly used in radiation fields including neutrons, protons and 
-rays. A response function for each particle is calculated by the radiation transport code FLUKA. To validate a response function to high energy neutrons, benchmark experiments with quasi mono-energetic neutrons have been carried out at RCNP, Osaka University. For neutron irradiation with energies below 200 MeV, very good agreement was found comparing the FLUKA simulations and the measurements. In addition it was found that at proton energies of 250 and 392 MeV, results calculated with neutron sources underestimate the experimental data due to a non-negligible gamma component originating from the target 
Li(p,n)Be reaction.
Matsumoto, Tetsuro*; Masuda, Akihiko*; Nishiyama, Jun*; Iwase, Hiroshi*; Iwamoto, Yosuke; Satoh, Daiki; Hagiwara, Masayuki*; Yashima, Hiroshi*; Yashima, Hiroshi*; Shima, Tatsushi*; et al.
EPJ Web of Conferences, 153, p.08016_1 - 08016_3, 2017/09
Times Cited Count：1 Percentile：61.03(Nuclear Science & Technology)Neutron energy spectra behind concrete and iron shields were measured for quasi-monoenergetic neutrons above 200 MeV using a Bonner sphere spectrometer (BSS). Quasi-monoenergetic neutrons were produced by the Li(p,xn) reaction with 246-MeV and 389-MeV protons. The response function of BSS was also measured at neutron energies from 100 MeV to 387 MeV. In data analysis, the measured response function was used and the multiple neutron scattering effect between the BSS and the shielding material was considered. The neutron energy spectra behind the concrete and iron shields were obtained by the unfolding method using the MAXED code. Ambient dose equivalents were obtained as a function of a shield thickness successfully. For the case of the 244 MeV neutron incidence, the multiple neutron scattering effect on the effective dose is large under 50 cm thickness of the concrete shield.
Si studied by angle-resolved photoelectron spectroscopy; Elucidating the contribution of U 5
states in URu
SiFujimori, Shinichi; Kobata, Masaaki; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Matsumoto, Yuji*; Yamamoto, Etsuji; Tateiwa, Naoyuki; et al.
Physical Review B, 96(12), p.125117_1 - 125117_9, 2017/09
Times Cited Count：10 Percentile：45.59(Materials Science, Multidisciplinary)Masuda, Akihiko*; Matsumoto, Tetsuro*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Sato, Tatsuhiko; Iwase, Hiroshi*; Yashima, Hiroshi*; Nakane, Yoshihiro; Nishiyama, Jun*; et al.
Nuclear Instruments and Methods in Physics Research A, 849, p.94 - 101, 2017/03
Times Cited Count：1 Percentile：10.58(Instruments & Instrumentation)Quasi-monoenergetic high-energy neutron fields induced by Li(p,n) reactions are used for the response evaluation of neutron-sensitive devices. The quasi-monoenergetic high-energy field consists of high-energy monoenergetic peak neutrons and unwanted continuum neutrons down to the low-energy region. A two-angle differential method has been developed to compensate for the effect of the continuum neutrons in the response measurements. In this study, the two-angle differential method was demonstrated for Bonner sphere detectors, which are typical examples of moderator-based neutron-sensitive detectors, to investigate the method's applicability and its dependence on detector characteristics. Through this study, the adequacy of the two-angle differential method was experimentally verified, and practical suggestions were made pertaining to this method.
Matsumoto, Toshinori; Ishikawa, Jun; Maruyama, Yu
Proceedings of 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) (USB Flash Drive), p.4033 - 4043, 2015/08
Tsukasaki, Yoshikazu*; Miyazaki, Naoyuki*; Matsumoto, Atsushi; Nagae, Shigenori*; Yonemura, Shigenobu*; Tanoue, Takuji*; Iwasaki, Kenji*; Takeichi, Masatoshi*
Proceedings of the National Academy of Sciences of the United States of America, 111(45), p.16011 - 16016, 2014/11
Times Cited Count：38 Percentile：63.49(Multidisciplinary Sciences)Ishida, Hisashi; Matsumoto, Atsushi
PLOS ONE (Internet), 9(7), p.e101951_1 - e101951_17, 2014/07
Times Cited Count：16 Percentile：43.78(Multidisciplinary Sciences)Li(p,n) reactionsIwamoto, Yosuke; Hagiwara, Masayuki*; Iwase, Hiroshi*; Yashima, Hiroshi*; Satoh, Daiki; Matsumoto, Tetsuro*; Masuda, Akihiko*; Pioch, C.*; Mares, V.*; Shima, Tatsushi*; et al.
Progress in Nuclear Science and Technology (Internet), 4, p.657 - 660, 2014/04
The authors measured the neutron energy spectra of the proton incident reaction on the lithium target with 137, 200, 246 and 389 MeV protons at several angles (0, 2.5, 5, 10, 15, 20, 25 and 30), using a time-of-flight (TOF) method employing organic scintillators NE213 at the Research Center for Nuclear Physics (RCNP) of Osaka University. For the neutron energy spectrum at 0, the ratio of the peak neutron intensity to the total one varied between 0.4 and 0.5 depending on the incident energy. In order to consider the correction required to derive the response in the peak region from the measured total response for high-energy neutron detectors, the authors showed the subtractions of H*(10) obtained at larger angles from the 0 data in the continuum part. It was found that subtracting the dose equivalent at about 22 from the 0 data reduces the continuum component most efficiency.
Matsumoto, Tetsuro*; Masuda, Akihiko*; Nishiyama, Jun*; Harano, Hideki*; Iwase, Hiroshi*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Yashima, Hiroshi*; Nakane, Yoshihiro; et al.
Progress in Nuclear Science and Technology (Internet), 4, p.332 - 336, 2014/04
Recently, many high-energy accelerators are used for various fields. Shielding data for high-energy neutrons are therefore very important from the point of view of radiation protection in high energy accelerator facilities. However, the shielding experimental data for high energy neutrons above 100 MeV are very poor both in quality and in quantity. In this study, neutron penetration spectral fluence and ambient dose through iron and concrete shields were measured with a Bonner sphere spectrometer (BSS). Quasi-monoenergetic neutrons were produced by the Li(p,xn) reaction by bombarding a 1-cm thick Li target with 246-MeV and 389-MeV protons in the Research Center for Nuclear Physics (RCNP) of the Osaka University. Shielding materials are iron blocks with a thickness from 10 cm to 100 cm and concrete blocks with a thickness from 25 cm to 300 cm.
Hagiwara, Masayuki*; Iwase, Hiroshi*; Iwamoto, Yosuke; Satoh, Daiki; Matsumoto, Tetsuro*; Masuda, Akihiko*; Yashima, Hiroshi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Sakamoto, Yukio; et al.
Progress in Nuclear Science and Technology (Internet), 4, p.327 - 331, 2014/04
We have developed several hundreds of MeV p-Li quasi-monoenergetic neutron fields in the Research Center for Nuclear Physics (RCNP), Osaka University, Japan. In this study, we extended the measurements to higher energy with a p-Li quasi-monoenergetic neutron source, which was produced from a 1.0-cm-thick lithium target bombarded with 246 and 389 MeV protons, using a larger NE213 scintillator of 25.4-cm in diameter and 25.4-cm in thickness. The large NE213 have good energy resolution for high energy neutrons, because it can stop recoil protons up to 180 MeV. The measured data are compared with the Monte-Carlo codes (PHITS with JENDL-HE data library) in the energy spectra, time spectra and the attenuation length of the peak neutrons. This comparison shows good agreement between experiments and calculations. The attenuation length estimated from the well-fitted curves with single exponential form will be useful for the practical shielding design of high energy accelerator facilities.
Nakane, Yoshihiro; Hagiwara, Masayuki*; Iwamoto, Yosuke; Iwase, Hiroshi*; Satoh, Daiki; Sato, Tatsuhiko; Yashima, Hiroshi*; Matsumoto, Tetsuro*; Masuda, Akihiko*; Nunomiya, Tomoya*; et al.
Progress in Nuclear Science and Technology (Internet), 4, p.704 - 708, 2014/04
no abstracts in English
cultivar "Aladdin 2" through stepwise improvements of cv. "Jimba" using ion beam re-irradiationUeno, Keiichiro*; Nagayoshi, Sanetaka*; Imakiire, Seiro*; Koriyama, Keisaku*; Minami, Tomohito*; Tanaka, Atsushi; Hase, Yoshihiro; Matsumoto, Toshikazu*
Engeigaku Kenkyu, 12(3), p.245 - 254, 2013/09
"Jimba" is a leading variety of white-flower chrysanthemum in Japan, although "Jimba" develops many axillary buds and also shows delayed flowering under a low temperature condition. Previously, we succeeded to produce new chrysanthemum variety "Aladdin" and "Imagine" that have a lesser number of axillary buds by ion beam irradiation. However, these varieties still show delayed flowering under a low temperature condition. In this study, we examined the effect of re-irradiation ofthese mutants by ion beams in improving flowering trait. The cultured leaves of "Aladdin" were irradiated with carbon ions and the regenerated plants were screened for the mutants that flowers earlier than the parental variety under a low temperature condition. Finally, we succeeded to produce new chrysanthemum variety "Aladdin 2" that develops a few axillary buds and shows early flowering traits. Thus, we demonstrated that the two important agronomic traits can be introduced by ion beam irradiation in a stepwise manner. The knowledge obtained in this study may be applicable for improving many kinds of plants.
Iwamoto, Yosuke; Hagiwara, Masayuki*; Matsumoto, Tetsuro*; Masuda, Akihiko*; Iwase, Hiroshi*; Yashima, Hiroshi*; Shima, Tatsushi*; Tamii, Atsushi*; Nakamura, Takashi*
Nuclear Instruments and Methods in Physics Research A, 690, p.10 - 16, 2012/10
Times Cited Count：4 Percentile：31.8(Instruments & Instrumentation)Secondary neutron-production double-differential cross sections (DDXs) have been measured from interactions of 137 MeV and 200 MeV protons in a natural carbon target. The data were measured between 0 and 25 in the laboratory. Benchmark calculations were carried out with the PHITS code using the evaluated nuclear data files of JENDL/HE-2007 and ENDF/B-VII, and the theoretical models of Bertini-GEM and ISOBAR-GEM. For the 137 MeV proton incidence, calculations using JENDL/HE-2007 generally reproduced the shape and the amount of experimental spectra well including the ground state of the 
N state produced by the C(p,n)N reaction. ISOBAR predicts the nucleon emission to the forward angles qualitatively better than the Bertini model and JENDL/HE-2007. These experimental data will be useful to evaluate the carbon data and as benchmark data for investigating the validity of the Monte Carlo simulation for the shielding design of accelerator facilities.
delocalization in ferromagnetic CeRuGe and paramagnetic CeRuSi observed by Ce 
XAS and XMCDOkane, Tetsuo; Takeda, Yukiharu; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji; Kimura, Noriaki*; Komatsubara, Takemi*; Aoki, Haruyoshi*
Physical Review B, 86(12), p.125138_1 - 125138_11, 2012/09
Times Cited Count：12 Percentile：46.48(Materials Science, Multidisciplinary)Uesaka, Takahiro; Kozawa, Masachiyo; Matsumoto, Junko; Endo, Masayuki; Kinoshita, Junichi; Suzuki, Takeshi; Suzuki, Hisao; Morishita, Satoru; Sakamoto, Yu
JAEA-Technology 2012-015, 29 Pages, 2012/06
JAEA-Technology-2012-015.pdf:3.22MB
In Japan Atomic Energy Agency Nuclear Science Research Institute waste treatment building No.2 treat intermediate-level solid waste. Solid wastes are reduced in volume by compaction. They are then canned in stainless can, which are subsequently put in 200-liter concrete-lined drums or 1-m
concrete containers, filled with concrete. To prepare for disposal in future, be able to make fit with the technical standard of waste package, we were asked to change the lid type shielded container. Therefore due to the change of lid type shielded container, we confirmed integrity of it with evaluation of close volt by drop analysis, evaluation of shielding, and drop test with a prototype model.
Masuda, Akihiko*; Matsumoto, Tetsuro*; Harano, Hideki*; Nishiyama, Jun*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Iwase, Hiroshi*; Yashima, Hiroshi*; Nakamura, Takashi*; et al.
IEEE Transactions on Nuclear Science, 59(1), p.161 - 166, 2012/02
Times Cited Count：12 Percentile：66.47(Engineering, Electrical & Electronic)In this study, responses of Bonner sphere spectrometer (BSS) for 245 and 388 MeV neutrons was measured at RCNP, Osaka University. The neutrons are generated in the Li(p,n) reaction and its spectra consist of a high-energy peak and a continuum down to the low energy. Therefore, the observed counts of BSS caused by the continuum need to be subtracted. Adjusting a Li target angle and a collimator position, 0 deg and 30 deg component of generated neutron are available. While the 0 deg component contains both the peak and the continuum, the 30 deg component is considered to contain only the continuum. Therefore, the response of the peak is obtained. The spectra were measured using the time-of-flight (TOF) method with a NE213 scintillator.
Matsumoto, Atsushi
Progress in Nuclear Science and Technology (Internet), 2, p.486 - 490, 2011/10
SiOkane, Tetsuo; Kawasaki, Ikuto; Yasui, Akira; Okochi, Takuo*; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji*; et al.
Journal of the Physical Society of Japan, 80(Suppl.A), p.SA060_1 - SA060_3, 2011/07
Times Cited Count：1 Percentile：11.3(Physics, Multidisciplinary)