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Rh
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Iwasa, Kazuaki*; Suyama, Kazuya*; Kawamura, Seiko; Nakajima, Kenji; Raymond, S.*; Steffens, P.*; Yamada, Akira*; Matsuda, Tatsuma*; Aoki, Yuji*; Kawasaki, Ikuto; et al.
Physical Review Materials (Internet), 7(1), p.014201_1 - 014201_11, 2023/01
Times Cited Count：2 Percentile：62.48(Materials Science, Multidisciplinary)Otsuka, Yusuke*; Kanazawa, Naoya*; Hirayama, Motoaki*; Matsui, Akira*; Nomoto, Takuya*; Arita, Ryotaro*; Nakajima, Taro*; Hanashima, Takayasu*; Ukleev, V.*; Aoki, Hiroyuki; et al.
Science Advances (Internet), 7(47), p.eabj0498_1 - eabj0498_9, 2021/11
Times Cited Count：8 Percentile：54.61(Multidisciplinary Sciences)Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count：13 Percentile：98.93(Quantum Science & Technology)Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11
Times Cited Count：3 Percentile：86.37(Physics, Atomic, Molecular & Chemical)Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12
Times Cited Count：7 Percentile：90.88(Physics, Atomic, Molecular & Chemical)Kiriyama, Hiromitsu; Mori, Michiaki; Suzuki, Masayuki*; Daito, Izuru*; Okada, Hajime; Ochi, Yoshihiro; Tanaka, Momoko; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; et al.
Reza Kenkyu, 42(6), p.441 - 447, 2014/06
We describe three specific high power laser systems that are being developed in our laboratory for many applications in high field science, nonlinear optics and material processing. We report on a femtosecond petawatt-class Ti:sapphire chirped-pulse amplification laser system that can produce a pulse energy of 20 J of 40 fs pulse duration, a picosecond high intensity Yb:YAG chirped-pulse amplification laser system that can generate a pulse energy of 100 mJ of 0.5 ps pulse duration, and a nanosecond high repetition rate Nd:YAG laser system that can provide an average power of 360 W with a pulse duration of 30 ns delivered at a 1 kHz repetition rate. We discuss the basic design aspects and present the results from our experimental investigations of these laser systems.
Suzuki, Masayuki; Kiriyama, Hiromitsu; Daito, Izuru; Okada, Hajime; Ochi, Yoshihiro; Sato, Masatoshi*; Yoshii, Takehiro*; Tamaoki, Yoshinori*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
AIP Conference Proceedings 1465, p.53 - 57, 2012/07
Times Cited Count：0 Percentile：0.13(Physics, Applied)We have reported hundred mJ level, femtosecond pulse duration with the high temporal contrast in an OPCPA/Yb:YAG ceramic thin disk laser system at 10 Hz repetition rate. At an input laser pulse energy of 3.8 mJ from the OPCPA preamplifer the output energy of 130 mJ with spectral bandwidth of 2.5 nm has been obtained from multipass Yb:YAG ceramic thin disk amplifier, and the optical efficiency from LD energy to amplified laser pulse is 9.6%. The recompressed laser pulse duration was measured to be 450 fs. Because the compressor efficiency exceeds 73% the compressed pulse energy can potentially be as high as 95 mJ. The contrast level of this laser pulse was measured to be less than 7.2
10
at -150 ps. This novel laser system after further amplification using additional amplifiers can be useful for the laser-driven proton acceleration in future.
Kiriyama, Hiromitsu; Suzuki, Masayuki*; Daito, Izuru; Okada, Hajime; Ochi, Yoshihiro; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
Reza Kenkyu, 40(2), p.143 - 145, 2012/02
We demonstrate a compact, high-spatiotemporal-quality, high-intensity diode-pumped Yb:YAG thin-disk chirped-pulse amplification (CPA) laser system that incorporates a nonlinear preamplifier based on optical parametric chirped-pulse amplification (OPCPA). The stretched pulses are amplified in the OPCPA preamplifier and the following Yb:YAG main amplifier to 
100 mJ at 10 Hz. The broadband amplified beam quality of 1.1 (horizontal direction) and 1.4 (vertical direction) times diffraction limited and pulse compression down to 470 fs with contrast of better than 10
have been achieved successfully.
Suzuki, Masayuki*; Kiriyama, Hiromitsu; Daito, Izuru; Ochi, Yoshihiro; Okada, Hajime; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
Applied Physics B, 105(2), p.181 - 184, 2011/11
Times Cited Count：5 Percentile：28.53(Optics)We have demonstrated an OPCPA/Yb:YAG ceramic thin disk hybrid laser system having hundred mJ level pulse energy sub-picosecond pulse duration with high temporal contrast. At an input energy of 3.8 mJ from an OPCPA preamplifier an output energy of 130 mJ was obtained from Yb:YAG ceramic thin disk amplifier. A recompressed pulse duration of 450 fs with a contrast level of less than 7.210
was obtained. The contrast level is the highest value achieved in Yb:YAG chirped pulse amplification (CPA) laser system with hundred mJ level.
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：11.26(Physics, Multidisciplinary)(Si
Ge
) studied by resonant soft X-ray ARPESOkane, Tetsuo; Okochi, Takuo*; Takeda, Yukiharu; Fujimori, Shinichi; Yasui, Akira; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji*; Sugi, Motoki*; et al.
Physica Status Solidi (B), 247(3), p.397 - 399, 2010/03
-derived Fermi surfaces of CeRu(SiGe) near the quantum critical point; Resonant soft-X-ray ARPES studyOkane, Tetsuo; Okochi, Takuo*; Takeda, Yukiharu; Fujimori, Shinichi; Yasui, Akira; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji*; Sugi, Motoki*; et al.
Physical Review Letters, 102(21), p.216401_1 - 216401_4, 2009/05
Times Cited Count：28 Percentile：76.99(Physics, Multidisciplinary)Sadakane, Kozo*; Arai, Akira*; Aoki, Wako*; Arimoto, Nobuo*; Hidai, Masahide*; Onishi, Takashi*; Tajitsu, Akito*; Beers, T. C.*; Iwamoto, Nobuyuki; Tominaga, Nozomu*; et al.
Publications of the Astronomical Society of Japan, 58(3), p.595 - 604, 2006/06
Times Cited Count：11 Percentile：31.80(Astronomy & Astrophysics)We report detailed spectroscopic studies performed for the secondary star in the black hole binary (micro-quasar) V4641 Sgr in order to examine its surface chemical composition and to see if its surface shows any signature of pollution by ejecta from a supernova explosion. We obtain abundances of 10 elements and find definite over-abundances of N (by 0.8 dex or more) and Na (by 0.8 dex) in V4641 Sgr. From line-by-line comparisons of eight other elements (C, O, Mg, Al, Si, Ti, Cr, Fe) between V4641 Sgr and the two normal late B-type stars, which have been reported to have solar abundances. An evolutionary model of a massive close binary system has been constructed to explain the abundances observed in V4641 Sgr. The model suggests that the BH forming supernova in this system was a dark one.
Ninokata, Hisashi*; Misawa, Takeharu*; Baglietto, E.*; Aoki, Takayuki*; Sorokin, A. P.*; Maekawa, Isamu*; Ohshima, Hiroyuki; Yamaguchi, Akira
JNC TY9400 2003-010, 170 Pages, 2003/03
JNC-TY9400-2003-010.pdf:5.42MB
A method of large scale direct numerical simulation of turbulent flows in a high burn-up fuel pin bundle is proposed to evaluate wall shear stress and temperature distributions on the pin surfaces as well as detailed coolant velocity and temperature distributions inside subchannels under various thermal hydraulic conditions. This simulation is aimed at providing a tool to confirm margins to thermal hydraulics design limits of the nuclear fuels and at the same time to be used in design-by-analysis approaches. The method will facilitate thermal hydraulic design of high performance LMFR core fuels characterized by high burn-up, ultra long life, high reliable and safe performances, easiness of operation and maintenance, minimization of radio active wastes, without much relying on such empirical approach as hot spot factor and sub-factors, and above all the high cost mock up experiments. A pseudo direct numerical simulation of turbulence (DNS) code is developed, first on the Cartesian coordinates and then on the curvilinear boundary fit coordinates that enables us to reproduce thermal hydraulics phenomena in such a complicated flow channel as subchannels in a nuclear fuel pin assembly. The coordinate transformation is evaluated and demonstrated to yield correct physical quantities by carrying out computations and comparisons with experimental data with respect to the distributions of various physical quantities and turbulence statistics for fluid flow and heat transfers in various kinds of simple flow channel geometry. Then the boundary fitted pseudo DNS for flows inside an infinite pin array configuration is carried out and compared with available detailed experimental data. In parallel similar calculations are carried out using a commercial code STAR-CD to cross-check the DNS performances. As a result, the pseudo DNS showed reasonable comparisons with experiments as well as the STAR-CD results. Importance of the secondary flow influences is emphasized on the momentum a
Takehisa, Masaaki*; Tagawa, Seiichi*; Kashiwagi, Masayuki*; Tominaga, Hiroshi*; Ishikawa, Isamu*; Ooka, Norikazu; Kamada, Toshimitsu*; Hosobuchi, Kazunari*; Makuuchi, Keizo; Takeshita, Hidefumi; et al.
Genshiryoku Riyo No Keizai Kibo; NSA/Commentaries, No.9, 139 Pages, 2001/01
no abstracts in English
-implanted 6H-SiC studied by monoenergetic positron beamsUedono, Akira*; Tanigawa, Shoichiro*; Oshima, Takeshi; Ito, Hisayoshi; Aoki, Yasushi; Yoshikawa, Masahito; Nashiyama, Isamu
Journal of Applied Physics, 86(10), p.5392 - 5398, 1999/00
Times Cited Count：10 Percentile：45.92(Physics, Applied)no abstracts in English
-implanted 6H-SiC using monoenergetic positron beamsUedono, Akira*; Oshima, Takeshi; Ito, Hisayoshi; Suzuki, Ryoichi*; ; Tanigawa, Shoichiro*; Aoki, Yasushi; Yoshikawa, Masahito; Nashiyama, Isamu; Mikado, Tomohisa*
Japanese Journal of Applied Physics, Part 1, 37(5A), p.2422 - 2429, 1998/05
Times Cited Count：13 Percentile：53.51(Physics, Applied)no abstracts in English
Oshima, Takeshi; Uedono, Akira*; Abe, Koji*; Ito, Hisayoshi; Aoki, Yasushi; Yoshikawa, Masahito; Tanigawa, Shoichiro*; Nashiyama, Isamu
Applied Physics A, 67(4), p.407 - 412, 1998/00
Times Cited Count：26 Percentile：72.51(Materials Science, Multidisciplinary)no abstracts in English
Oshima, Takeshi; Uedono, Akira*; Ito, Hisayoshi; Abe, Koji*; Suzuki, Ryoichi*; ; Aoki, Yasushi; Tanigawa, Shoichiro*; Yoshikawa, Masahito; Mikado, Tomohisa*; et al.
Mater. Sci. Forum, 264-268, p.745 - 748, 1998/00
no abstracts in English
Ito, Hisayoshi; Oshima, Takeshi; Aoki, Yasushi; Abe, Koji*; Yoshikawa, Masahito; Nashiyama, Isamu; Okumura, Hajime*; Yoshida, Sadafumi*; Uedono, Akira*; Tanigawa, Shoichiro*
Journal of Applied Physics, 82(11), p.5339 - 5347, 1997/12
Times Cited Count：13 Percentile：57.40(Physics, Applied)no abstracts in English
