Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sumida, Kazuki; Higaki, Sota*; Sato, Hitoshi*; Tsuru, Daichi*; Miyamoto, Koji*; Okuda, Taichi*; Kuroiwa, Yoshihiro*; Moriyoshi, Chikako*; Takase, Koichi*; Oguchi, Tamio*; et al.
Journal of the Physical Society of Japan, 92(8), p.084706_1 - 084706_6, 2023/08
Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)Kondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
Times Cited Count:20 Percentile:95.45(Multidisciplinary Sciences)no abstracts in English
Terasawa, Yukana*; Ohara, Takashi; Sato, Sota*; Yoshida, Satoshi*; Asahi, Toru*
Acta Crystallographica Section E; Crystallographic Communications (Internet), 78(3), p.306 - 312, 2022/03
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:3 Percentile:35.51(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:3 Percentile:35.51(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.
Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.
Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08
Times Cited Count:16 Percentile:82.84(Optics)Ishii, Kenji*; Toyama, Takami*; Asano, Shun*; Sato, Kentaro*; Fujita, Masaki*; Wakimoto, Shuichi; Tsutsui, Kenji*; Sota, Shigetoshi*; Miyawaki, Jun*; Niwa, Hideharu*; et al.
Physical Review B, 96(11), p.115148_1 - 115148_8, 2017/09
Times Cited Count:32 Percentile:78.06(Materials Science, Multidisciplinary)Ishiyama, Hironobu*; Jeong, S.-C.*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Jung, H. S.*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Osa, Akihiko; Otokawa, Yoshinori; et al.
Nuclear Instruments and Methods in Physics Research B, 376, p.379 - 381, 2016/06
Times Cited Count:8 Percentile:57.38(Instruments & Instrumentation)Ishiyama, Hironobu*; Jeong, S.-C.*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Katayama, Ichiro*; Osa, Akihiko; Otokawa, Yoshinori; et al.
Japanese Journal of Applied Physics, 53(11), p.110303_1 - 110303_4, 2014/11
Times Cited Count:5 Percentile:21.59(Physics, Applied)Ando, Masanori; Watanabe, Sota*; Kikuchi, Koichi*; Otani, Tomomi*; Sato, Kenichiro*; Tsukimori, Kazuyuki; Asayama, Tai
Proceedings of 2013 ASME Pressure Vessels and Piping Conference (PVP 2013) (DVD-ROM), 11 Pages, 2013/07
New 2012 edition of JSME code for design and construction of fast reactors (FRs code) was published by Japan society of mechanical engineers (JSME). Main topic of the current JSME FRs code 2012 edition is registration of the two new materials, 316FR and Mod.9Cr-1Mo steel. The design margins for the new materials to the rules for the components and piping serviced at elevated temperature described in the JSME FRs code were assessed. To confirm the design margins, a series of the assessment program for the new materials to the conventional design rules was performed using the evaluation of the experimental data and finite element analysis. Through these assessments, the enough design margins for new materials to the rules were confirmed.
Hosotani, Risa; Sato, Naomitsu*; Shimizu, Takehiko; KOBAYASHI, Hideo
Saikuru Kiko Giho, (25), p.25 - 32, 2004/00
To observe the airborne gamma radiation dose rate, monitoring posts are set up to a border of supervised area of JNC-OEC. Measurement values of some ionization chambers set at monitoring posts were increased by unknown origin signal at random times. To probe the cause, measurement of electric field intensity at the ionization chamber and immunity test at anechoic chamber are carry out. Result of examination made clear that measurement values are increased by specific frequency band electromagnetic wave. They were also clearly that ferrite cores and shield tube are effective as eliminate of an electromagnetic wave noise. When ferrite cores are attached to cables of ionization chambers, unknown increase of measurement value doesn't occur.
Konishi, Ren*; Okutsu, Kenichi*; Kino, Yasushi*; Sasaki, Kyosuke*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; et al.
no journal, ,
We are attempting to observe regenerative muons emitted from the surface of a solid hydrogen thin film by muon-catalyzed fusion by irradiating the film with muons that have the same charge as electrons and 207 times the mass of electrons. The main background factors in detecting regenerative muons are scattered muons from the accelerator, which are slowed down to the same level as regenerative muons by the target, and bremsstrahlung generated by the components of the device. The results show that there is little scattering within the solid hydrogen, and that the dominant slowing down process is at the Al foil upstream of the solid hydrogen target. The energy distribution of Bremsstrahlung at the X-ray detection position will be reported.
Ikemoto, Megumi*; Somekawa, Jun*; Neki, Arata*; Konishi, Ren*; Nakashima, Ryota*; Okutsu, Kenichi*; Kino, Yasushi*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; et al.
no journal, ,
We have been studying on muon beam quality improvement by moderating generated by an accelerator with a thin Si film, and then decelerating and focusing the beam in an electrostatic field. In this study, numerical simulation of an experiment in which of a few MeV is injected into a 0.5~mm thick Si plate and , which is decelerated to a few keV, is extracted electrostatically is performed using charged particle orbit software (SIMION). The flight time to the end of the transport tube and the transport efficiency change with a slight shift of the muon launch position, suggesting that the muon transport process is sensitive to the initial conditions.
Ikemoto, Megumi*; Somekawa, Jun*; Neki, Arata*; Konishi, Ren*; Nakashima, Ryota*; Okutsu, Kenichi*; Kino, Yasushi*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; et al.
no journal, ,
no abstracts in English
Yamashita, Takuma*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
A muon () having 207 times larger mass of electron and the same charge as the electron has been known to catalyze a nuclear fusion (CF) between deuteron (d) and triton (t). In this work, we have solved simultaneous reaction rate equations by the 4th-order Runge-Kutta method for the jointed CF cycles in the two layers (H/D and D/T). The T concentration to maximize the intensities of fusion neutrons and muons emitted to the vacuum will be discussed.
Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
Muon catalized fusion (CF) is expected to be a high-quality muon beam source for undestructive measurement and a monoenergetic neutron source. In this work, we attemped to observe a released muon after intermolecular nuclear reaction using muonic X-ray.
Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
Muon catalized fusion (CF) is expected to be a high-quality muon beam source for undestructive measurement and a monoenergetic neutron source. In this work, we discussed how to observe a kinetic energy distribution of a recycling muon emitted after CF reaction.
Miyashita, Konan*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
To observe a kinetic energy distribution of a recycling muon emitted after CF reaction, it is necessary to guide the recycling muons to a detector. In this work, we simulated the muon transportation using PHITS code and designed an experimental system.
Nakashima, Ryota*; Okutsu, Kenichi*; Kino, Yasushi*; Miyashita, Konan*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
no journal, ,
The recycling muon emitted after the muon catalized fusion (CF) has a kinetic energy between a few keV to 10 keV. To observed the kinetic energy distribution of the recycling muon, we have to guide and inject muons to Ti foil, and measure the muonic X-ray. In this work, we utilized SIMION code to calculate the electric field and the trajectory of muons from deuteron target to Ti foil.
Konishi, Ren*; Okutsu, Kenichi*; Kino, Yasushi*; Sasaki, Kyosuke*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Yamashita, Takuma*; Okada, Shinji*; Sato, Motoyasu*; et al.
no journal, ,
When muons are injected into a deuterium thin film target, muon molecules are formed. The muons released after intramolecular fusion (recycling muons) are important for the development of slow muon beams. In this study, corresponding to an experiment in which recycling muons are transported using a coaxial transport tube, the energy distribution of scattered muons, muons after deceleration, and background radiation due to bremsstrahlung by decay electrons and neutrons are analyzed by numerical simulations.