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Shimizu, Kazuyuki*; Toda, Hiroyuki*; Hirayama, Kyosuke*; Fujihara, Hiro*; Tsuru, Tomohito; Yamaguchi, Masatake; Sasaki, Taisuke*; Uesugi, Masayuki*; Takeuchi, Akihisa*
International Journal of Hydrogen Energy, 109, p.1421 - 1436, 2025/03
Times Cited Count：2 Percentile：93.94(Chemistry, Physical)Our preceding investigation revealed that multiple hydrogen traps at coherent interfaces of MgZn
precipitates initiated spontaneous interface decohesion, causing hydrogen-induced quasicleavage cracking in Al-Zn-Mg alloys. Herein, we performed a quantitative and systematic investigation to discern the mechanisms by which hydrogen trapped at coherent/semi-coherent interfaces of precipitates could influence macroscopic hydrogen embrittlement by modulating the coherent interface of MgZn through aging. To explore this hydrogen embrittlement phenomenon based on hydrogen trapping at the precipitate interface, we determined the hydrogen trapping energy of the semi-coherent MgZn interface via first-principles calculations (0.56 eV/atom). Hydrogen partitioning of all hydrogen trapping sites, including vacancies, grain boundaries, and coherent and semi-coherent MgZn interfaces, revealed that in overaged alloys, over 90% of the hydrogen was sequestered at semi-coherent interfaces. Owing to the inherent characteristics of the MgZn interface, the hydrogen sequestered at the semi-coherent interface decreased the interfacial cohesive energy, causing semispontaneous decohesion of the interface and quasicleavage fracture in the Al-Zn-Mg alloys. These results implied that intergranular fracture was not directly induced by hydrogen trapped at grain boundaries but rather by the decohesion of precipitate interfaces along grain boundaries.
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.
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.
Konishi, Ren*; Okutsu, Kenichi*; Kino, Yasushi*; Sasaki, Kyosuke*; Nakashima, Ryota*; Yamashita, Takuma*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; 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 used PHITS code to simulate the behavior of the low-energy muon in a thin layer of the solid hydrogen.
