Tsutsui, Satoshi; Higashinaka, Ryuji*; Nakamura, Raito*; Fujiwara, Kosuke*; Nakamura, Jin*; Kobayashi, Yoshio*; Ito, Takashi; Yoda, Yoshitaka*; Kato, Kazuo*; Nitta, Kiyofumi*; et al.
Hyperfine Interactions, 242(1), p.32_1 - 32_10, 2021/12
Maruyama, Ryuji; Yamazaki, Dai; Aoki, Hiroyuki; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Soyama, Kazuhiko; Bigault, T.*; Saerbeck, T.*; Courtois, P.*
Journal of Applied Physics, 130(8), p.083904_1 - 083904_10, 2021/08
Maruyama, Ryuji; Yamazaki, Dai; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Aoki, Hiroyuki; Soyama, Kazuhiko
JPS Conference Proceedings (Internet), 33, p.011092_1 - 011092_6, 2021/03
no abstracts in English
Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Nakane, Tomohiro*; Yoneyama, Shota*; Kodama, Takeshi*; Kikuchi, Koichi*; Nakao, Akiko*; Ohara, Takashi; Higashinaka, Ryuji*; Matsuda, Tatsuma*; Aoki, Yuji*; Fujita, Wataru*
Dalton Transactions (Internet), 48(1), p.333 - 338, 2019/01
Ohashi, Hirofumi; Goto, Minoru; Ueta, Shohei; Sato, Hiroyuki; Fukaya, Yuji; Kasahara, Seiji; Sasaki, Koei; Mizuta, Naoki; Yan, X.; Aoki, Takeshi*
Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 6 Pages, 2018/10
Conceptual design study of an experimental HTGR is performed to upgrade the plant system from Japanese High Temperature engineering Test Reactor (HTTR) to a commercial HTGR. Safety systems of HTTR are upgraded to demonstrate the commercial HTGR concept, such as a passive reactor cavity cooling system, a confinement, etc. An intermediate heat exchanger (IHX) is replaced by a steam generator (SG) for a process heat supply to demonstrate the technology for a commercial use. This paper describes the conceptual design study results of the plant system of the experimental HTGR.
Maruyama, Ryuji; Yamazaki, Dai; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Aoki, Hiroyuki; Takeda, Masayasu; Soyama, Kazuhiko
Nuclear Instruments and Methods in Physics Research A, 888, p.70 - 78, 2018/04
The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with fabricated showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the range where the correction for the polarization inefficiencies of the beamline works properly.
Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11
Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12
Matsumoto, Yuji*; Haga, Yoshinori; Tateiwa, Naoyuki; Aoki, Haruyoshi*; Kimura, Noriaki*; Yamamura, Tomoo*; Yamamoto, Etsuji; Matsuda, Tatsuma*; Fisk, Z.*; Yamagami, Hiroshi*
Journal of the Physical Society of Japan, 85(10), p.104709_1 - 104709_7, 2016/10
Matsumoto, Yuji; Haga, Yoshinori; Tateiwa, Naoyuki; Yamamoto, Etsuji; Kimura, Noriaki*; Aoki, Haruyoshi*; Fisk, Z.
JPS Conference Proceedings (Internet), 3, p.011097_1 - 011097_5, 2014/06
Matsumoto, Yuji*; Haga, Yoshinori; Tateiwa, Naoyuki; Aoki, Haruyoshi*; Kimura, Noriaki*; Matsuda, Tatsuma*; Yamamoto, Etsuji; Fisk, Z.; Yamagami, Hiroshi*
JPS Conference Proceedings (Internet), 3, p.011096_1 - 011096_5, 2014/06
Tsutsui, Satoshi; Kaneko, Koji; Miyazaki, Ryoichi*; Higashinaka, Ryuji*; Aoki, Yuji*; Kobayashi, Riki*; Wakimoto, Shuichi; Baron, A. Q. R.*; Sugawara, Hitoshi*; Sato, Hideyuki*
JPS Conference Proceedings (Internet), 3, p.011060_1 - 011060_5, 2014/06
Matsumura, Takeshi*; Michimura, Shinji*; Inami, Toshiya; Hayashi, Yuya*; Fushiya, Kengo*; Matsuda, Tatsuma*; Higashinaka, Ryuji*; Aoki, Yuji*; Sugawara, Hitoshi*
Physical Review B, 89(16), p.161116_1 - 161116_5, 2014/04
The antiferromagnetic ordered phase below = 16.5 K and the unresolved intermediate phase between and (= 14 K) in SmRuP have been studied by resonant and nonresonant X-ray diffraction. In the intermediate phase, nonresonant Thomson scattering with = (1,0,0) is induced by applying a magnetic field. This phenomena is caused by atomic displacements reflecting the charge order in the band, as predicted theoretically. Simultaneously, the antiferromagnetic moment of Sm is enhanced along the field direction, which is considered to reflect the staggered ordering of the - crystal-field states. The present results show that the orbital-dependent - hybridization in association with the nesting instability in the band gives rise to the unconventional charge order similarly with PrRuP and PrFeP.
Matsumoto, Yuji; Kimura, Noriaki*; Komatsubara, Takemi*; Aoki, Haruyoshi*; Kurita, Nubuyuki*; Terashima, Taichi*; Uji, Shinya*
Journal of Physics; Conference Series, 391, p.012042_1 - 012042_4, 2012/12
CeRuSi is a paramagnetic heavy fermion compound with the electronic specific heat coefficient of 350 mJ/mol K. When a magnetic field is applied along the  direction of its tetragonal ThCrSi structure, it exhibits metamagnetic transition at 7.7 T. On the other hand, when a magnetic field is applied in the (001) plane, metamagnetic transition does not occur. This magnetic anisotropy is maintained to lower Ce concentration samples. By replacing Ce with La, CeRuSi changes to antiferromagnet at 0.91 and finally to normal paramagnet of LaRuSi. In very low Ce concentration samples, the impurity Kondo effect is observed. The Kondo temperature of the = 0.02 sample is about 1 K. We have successfully observed all the dHvA oscillations in the dilute Ce concentration samples with fields in the (001) plane. Moreover, we have observed the variation of the dHvA oscillations with temperature crossing the Kondo temperature.
Iwasa, Kazuaki*; Hao, L.*; Kogi, Masafumi*; Kuwahara, Keitaro*; Mignot, J.-M.*; Sugawara, Hitoshi*; Aoki, Yuji*; Matsuda, Tatsuma; Sato, Hideyuki*
Journal of the Physical Society of Japan, 81(9), p.094711_1 - 094711_9, 2012/09
Okane, 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
Takeda, Yukiharu; Saito, Yuji; Saito, Hiroyuki; Machida, Akihiko; Aoki, Katsutoshi; Yamagami, Hiroshi; Muro, Takayuki*; Kato, Yukako*; Kinoshita, Toyohiko*
Physical Review B, 84(15), p.153102_1 - 153102_4, 2011/10
We have performed soft X-ray emission spectroscopy (SXES) and soft X-ray absorption spectroscopy (SXAS) experiments on aluminum hydride -AlH. The occupied and unoccupied electronic states of the Al 3 partial density of states are obtained experimentally. By comparing the data from Al metal and -AlH, a band gap with a few eV is found for -AlH. In addition, the occupied states of -AlH have a larger spectral intensity than that of Al metal, indicating an increase in the number of electrons with the Al 3 character through Al-H bond formations. The results of a band-structure calculation account for the formation of the energy gap and the increase of the Al 3 electrons qualitatively. This suggests that a covalent-like nature is important to the Al-H bond in -AlH.
Okane, 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
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.