Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Takayanagi, Tomohiro; Fuwa, Yasuhiro; Otani, Masashi*; Shimomura, Koichiro*; Mibe, Tsutomu*; Kondo, Yasuhiro; Futatsukawa, Kenta*; Cicek, E.*; Nakazawa, Yuga*; Tokuchi, Akira*; et al.
Proceedings of 16th International Particle Accelerator Conference (IPAC25) (Internet), p.1884 - 1886, 2025/11
We have been developing a compact pulse power supply with high output and high frequency specifications: output voltage of 75 kV, current of 40 A, main pulse width of 50 us, and repetition frequency of 25 Hz for short pulse waveforms. This power supply is used to drive klystron for muon linac, which requires high stability and reliability. It uses a next-generation power semiconductor SiC-MOSFET with excellent characteristics of ultra-high withstand voltage of 13 kV and low loss, which was realized through the technological development of wide band gap semiconductor devices. Combining this SiC-MOSFET with the Marx circuit that generates ultra-high voltage pulses will realize a more compact pulse power supply with lower losses than conventional ones. In addition, future ap-plications in portable accelerators are also possible. In this presentation, the circuit design of the Marx power supply will be reported.
Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Natori, Hiroaki*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Tampo, Motonobu*; Kawamura, Naritoshi*; Teshima, Natsuki*; et al.
Journal of Physics; Conference Series, 2462, p.012033_1 - 012033_5, 2023/03
Times Cited Count：2 Percentile：91.47(Physics, Applied)Okutsu, Kenichi*; Yamashita, Takuma*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
Fusion Engineering and Design, 170, p.112712_1 - 112712_4, 2021/09
Times Cited Count：5 Percentile：38.44(Nuclear Science & Technology)A muonic molecule which consists of two hydrogen isotope nuclei (deuteron (d) or tritium (t)) and a muon decays immediately via nuclear fusion and the muon will be released as a recycling muon, and start to find another hydrogen isotope nucleus. The reaction cycle continues until the muon ends up its lifetime of 2.2 
s. Since the muon does not participate in the nuclear reaction, the reaction is so called a muon catalyzed fusion (CF). The recycling muon has a particular kinetic energy (KE) of the muon molecular orbital when the nuclear reaction occurs. Since the KE is based on the unified atom limit where distance between two nuclei is zero. A precise few-body calculation estimating KE distribution (KED) is also in progress, which could be compared with the experimental results. In the present work, we observed recycling muons after CF reaction.
Yamashita, Takuma*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
Fusion Engineering and Design, 169, p.112580_1 - 112580_5, 2021/08
Times Cited Count：4 Percentile：31.16(Nuclear Science & Technology)A muon () having 207 times larger mass of electron and the same charge as the electron has been known to catalyze a nuclear fusion between deuteron (d) and triton (t). These two nuclei are bound by and form a muonic hydrogen molecular ion, dt. Due to the short inter-nuclear distance of dt, the nuclear fusion, d +t
+ n + 17.6 MeV, occurs inside the molecule. This reaction is called muon catalyzed fusion (CF). Recently, the interest on CF is renewed from the viewpoint of applications, such as a source of high-resolution muon beam and mono-energetic neutron beam. In this work, we report a time evolution calculation of CF in a two-layered hydrogen isotope target.
Zhang, Z.*; Nishikino, Masaharu; Nishimura, Hiroaki*; Kawachi, Tetsuya; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Ogura, Koichi; Yogo, Akifumi; Okano, Yasuaki*; et al.
Optics Express (Internet), 19(5), p.4560 - 4565, 2011/02
Times Cited Count：20 Percentile：65.59(Optics)
line emission from Mo and Ag plate were experimentally studied by using ultra-high intensity, clean femtosecond laser pulses. Absolutely yield of X-rays at 17 keV from Mo and 22 keV from Ag were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significant enhancement of yields were obtained for both Mo and Ag with higher contrast ratios and high irradiance. The conversion efficiencies of 4.28 
10
/sr for Mo and 4.84 10/sr for Ag, the highest values ever obtained, have been demonstarted with the contrast ratio of 10
to 10
.
Shimomura, Koji*; Takenaga, Hidenobu; Tsutsui, Hiroaki*; Mimata, Hideyuki*; Iio, Shunji*; Miura, Yukitoshi; Tani, Keiji; Kubo, Hirotaka; Sakamoto, Yoshiteru; Hiratsuka, Hajime; et al.
Fusion Engineering and Design, 82(5-14), p.953 - 960, 2007/10
Times Cited Count：3 Percentile：24.10(Nuclear Science & Technology)no abstracts in English
Shimomura, Yasuo; Tsunematsu, Toshihide; Yamamoto, Shin; Maruyama, So; Mizoguchi, Tadanori*; Takahashi, Yoshikazu; Yoshida, Kiyoshi; Kitamura, Kazunori*; Ioki, Kimihiro*; Inoue, Takashi; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 78(Suppl.), 224 Pages, 2002/01
no abstracts in English
Shimomura, Hiroaki
JAERI-Research 96-034, 73 Pages, 1996/06
JAERI-Research-96-034.pdf:2.47MB
no abstracts in English
Shimomura, Hiroaki
Nihon Genshiryoku Gakkai-Shi, 38(10), p.803 - 813, 1996/00
Times Cited Count：1 Percentile：14.04(Nuclear Science & Technology)no abstracts in English
Shimomura, Hiroaki;
4th Int. Symp. on Magnetic Bearings,Proc., 0, p.383 - 387, 1994/00
no abstracts in English
Inagaki, Yoshiyuki; Takada, Shoji; ; ; Ota, Yukimaru; Shimomura, Hiroaki;
Nucl. Eng. Des., 146, p.301 - 309, 1994/00
Times Cited Count：6 Percentile：51.22(Nuclear Science & Technology)no abstracts in English
Ioka, Ikuo; Suzuki, Kunihiro; Inagaki, Yoshiyuki; Kunitomi, Kazuhiko; ; Shimomura, Hiroaki
Nihon Genshiryoku Gakkai-Shi, 32(12), p.1221 - 1223, 1990/12
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
Shimomura, Hiroaki; Kawaji, Satoshi; Ota, Yukimaru
Proc. of the 2nd Int. Symp. on Magnetic Bearings, p.93 - 99, 1990/00
no abstracts in English
Shimomura, Hiroaki; Kawaji, Satoshi
Proc. of the IAEA Specialists' Meeting on Communication and Data Transfer in NPP, 17 Pages, 1990/00
no abstracts in English
Shimomura, Hiroaki; Kawaji, Satoshi; Fujisaki, Katsuo;
JAERI-M 89-064, 90 Pages, 1989/06
no abstracts in English
CHino, Ryutaro; Maruyama, So; Takase, Kazuyuki; ; Shimomura, Hiroaki
Nihon Genshiryoku Gakkai-Shi, 31(4), p.470 - 476, 1989/04
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
Shimomura, Hiroaki; Kawaji, Satoshi; Fujisaki, Katsuo;
Gas-Cooled Reactor Coolant Circulator and Blower Technology, p.148 - 156, 1988/00
no abstracts in English
CHino, Ryutaro; Takase, Kazuyuki; Maruyama, So; Izawa, Naoki; ; Shimomura, Hiroaki;
Nihon Genshiryoku Gakkai-Shi, 30(4), p.343 - 349, 1988/00
Times Cited Count：1 Percentile：19.42(Nuclear Science & Technology)no abstracts in English
Miyashita, Konan*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
Muon catalyzed fusion (CF) is a cyclic reaction where a negatively charged muon itself acts like a catalyst of nuclear fusion between hydrogen isotopes. In this work, we have designed the shape of the thermal shield to reduce the background noise.
Nakashima, Ryota*; Okutsu, Kenichi*; Kino, Yasushi*; Miyashita, Konan*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
We are developing an experimental system to measure the kinetic energy distribution of regenerated muons emitted after muon catalytic nuclear reactions. The trajectory of the regenerated muon emitted from a solid hydrogen target, and the transport efficiency of the regenerated muon and its dependence on the emitted position are calculated/discussed using SIMION code.
