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Ogawa, Shuichi*; Tsuda, Yasutaka; Sakamoto, Tetsuya*; Okigawa, Yuki*; Masuzawa, Tomoaki*; Yoshigoe, Akitaka; Abukawa, Tadashi*; Yamada, Takatoshi*
Applied Surface Science, 605, p.154748_1 - 154748_6, 2022/12
Times Cited Count：4 Percentile：45.85(Chemistry, Physical)Immersion of graphene in KOH solution improves its mobility on SiO
/Si wafers. This is thought to be due to electron doping by modification with K atoms, but the K atom concentration C
in the graphene has not been clarified yet. In this study, the C was determined by XPS analysis using high-brilliance synchrotron radiation. The time evolution of C was determined by real-time observation, and the C before irradiation of synchrotron radiation was estimated to be 0.94%. The C 1s spectrum shifted to the low binding energy side with the desorption of K atoms. This indicates that the electron doping concentration into graphene is decreasing, and it is experimentally confirmed that K atoms inject electrons into graphene.
Watanabe, Tamaki*; Toyama, Takeshi*; Hanamura, Kotoku*; Imao, Hiroshi*; Kamigaito, Osamu*; Kamoshida, Atsushi*; Kawachi, Toshihiko*; Koyama, Ryo*; Sakamoto, Naruhiko*; Fukunishi, Nobuhisa*; et al.
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1105 - 1108, 2019/07
Upgrades for the RIKEN heavy-ion linac (RILAC) involving a new superconducting linac (SRILAC) are currently underway at the RIKEN radioactive isotope beam factory (RIBF). It is crucially important to develop nondestructive beam measurement diagnostics. We have developed a beam energy position monitor (BEPM) system which can measure not only the beam position but also the beam energy simultaneously by measuring the time of flight of the beam. We fabricated 11 BEPMs and completed the position calibration to obtain the sensitivity and offset for each BEPMs. The position accuracy has been achieved to be less than 
0.1 mm by using the mapping measurement.
Watanabe, Tamaki*; Imao, Hiroshi*; Kamigaito, Osamu*; Sakamoto, Naruhiko*; Fukunishi, Nobuhisa*; Fujimaki, Masaki*; Yamada, Kazunari*; Watanabe, Yutaka*; Koyama, Ryo*; Toyama, Takeshi*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.49 - 54, 2018/08
no abstracts in English
(Mn
Fe
)Si(111) epitaxially grown on Ge(111)Kawakubo, Yuki*; Noguchi, Masaya*; Hirata, Tomoaki*; Narumi, Kazumasa; Sakai, Seiji; Yamada, Shinya*; Hamaya, Kohei*; Miyao, Masanobu*; Maeda, Yoshihito
Physica Status Solidi (C), 10(12), p.1828 - 1831, 2013/12
Times Cited Count：0 Percentile：0.01(Nanoscience & Nanotechnology)Yamashita, Susumu; Yonemoto, Yukihiro; Yamada, Tomonori; Kunugi, Tomoaki*; Muramatsu, Toshiharu
Yosetsu Gakkai Rombunshu (Internet), 29(3), p.48s - 52s, 2011/08
Quantitative evaluation and controlling the residual stress which is induced by laser welding is of important problem for a life extension of FBRs (Fast Breeder Reactors) and the guarantee of the reliability of the repair processes. Numerical simulation is an effective tool for deep understanding of their problems and it needs to have high accuracy, robustness and reliability. We have recently constructed the fully parallelized laser welding simulation code which satisfies above aspects using some advanced numerical models. Concretely, VSIAM3 numerical model as the spatial discretization, an efficient free surface capturing scheme, THINC scheme, and FAVOR method as the solid phase expression has been applied to the code. We have conducted laser welding simulations and obtained some reasonable results. Therefore, the numerical model will be contributed to the repairing technology of a laser welding.
Yamashita, Susumu; Yonemoto, Yukihiro; Yamada, Tomonori; Kunugi, Tomoaki*; Muramatsu, Toshiharu
no journal, ,
Quantitative evaluation and controlling the residual stress which is induced by laser welding is of important problemfor a life extension of FBRs (Fast Breeder Reactors) and the guarantee of the reliability of the repair processes. Numerical simulation is an effective tool for deep understanding of their problems and it needs to have high accuracy, robustness and reliability. We have recently constructed the fully parallelized laser welding simulation code which satisfies above aspects using some advanced numerical models. Concretely, VSIAM3 (Volume and Surface Integrated Average based Multi Moment Method) numerical model as the spatial discretization, an efficient free surface capturing scheme, THINC scheme, and FAVOR method as the solid phase expression has been applied to the code. We have conducted modest large-scale laser welding simulations by using a supercomputer in Japan Atomic Energy Agency and obtained some preliminary results. And reasonable results were obtained.
Yamashita, Susumu; Yamada, Tomonori; Yonemoto, Yukihiro; Kunugi, Tomoaki*; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
Yonemoto, Yukihiro; Kunugi, Tomoaki*; Yamada, Tomonori; Yamashita, Susumu; Nishimura, Akihiko; Daido, Hiroyuki; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
Yamashita, Susumu; Yamada, Tomonori; Kunugi, Tomoaki*; Muramatsu, Toshiharu
no journal, ,
Toward the phenomenological understanding of laser welding repair processes for various reactor components by numerical simulation, we constructed laser welding simulation code which can treat combined physical phenomena including interfaces, a phase change and stress distribution in the base material using advanced numerical models. In the calculations of low-power density laser welding, we obtained particular results in the welding, e.g., thermal-shaped molten pool and a welding bead. Therefore, our numerical code will be appropriate tool for elucidating laser welding phenomena in the near future.
Yamashita, Susumu; Yamada, Tomonori; Kunugi, Tomoaki*; Muramatsu, Toshiharu
no journal, ,
Toward the phenomenological understanding of laser welding repair processes for various reactor components by numerical simulation, we constructed laser welding simulation code which can treat combined physical phenomena including interfaces, a phase change and stress evaluation in solid materials using several advanced numerical models. In the calculations of low-power density laser welding, we obtained particular results in the welding, e.g., thermal-shaped molten pool, a welding bead and a stress distribution around the molten pool. Therefore, our numerical code will be appropriate tool for elucidating laser welding phenomena in the near future.
Yamashita, Susumu; Yamada, Tomonori; Kunugi, Tomoaki*; Muramatsu, Toshiharu
no journal, ,
Yamashita, Susumu; Yamada, Tomonori; Kunugi, Tomoaki*; Muramatsu, Toshiharu
no journal, ,
Toward the phenomenological understanding of laser welding repair processes and controlling the residual stress for various reactor components by numerical simulation, we constructed laser welding simulation code which can treat combined physical phenomena including interfaces, a phase change and stress evaluation in solid materials using several advanced numerical models. In this paper, we report the evaluation of the characteristics of a molten pool. We carried out spot welding simulations using several physical properties of molten pool, e.g. viscosity and thermal conductivity, which aim to investigate an influence of turbulent viscosity. As a result, we found that the behavior of convection in the molten pool is closely related to the temperature distribution which will be the important role for a residual stress.
InO
Hayakawa, Kazutaka*; Nagasaki, Takanori*; Yamada, Tomoaki*; Yoshino, Masahito*; Igawa, Naoki; Hoshikawa, Akinori*; Ishigaki, Toru*
no journal, ,
Static disorder in the crystal structure of perovskite-type proton conducting oxide BaSnInO is investigated by atomistic simulation based on empirical potentials. The neutron scattering length density distribution for Ba and O obtained by the simulation is similar to that obtained by analyzing the neutron powder diffraction data using maximum entropy method.
Kwon, E.*; Komatsu, Kenichiro*; Yamada, Yoichi*; Hasegawa, Yuri*; Sato, Sho*; Sakai, Seiji; Kawachi, Kazuhiko*; Yokoo, Kuniyoshi*; Ono, Shoichi*; Kasama, Yasuhiko*; et al.
no journal, ,
Hosokawa, Tomoaki*; Fujiwara, Hideki*; Kamoshida, Shuichi*; Anzai, Kiyoshi*; Nakano, Masanao; Koike, Yuko; Yamada, Ryohei; Nagaoka, Mika
no journal, ,
no abstracts in English
Nakano, Masanao; Koike, Yuko; Yamada, Ryohei; Nagaoka, Mika; Hosokawa, Tomoaki*; Fujiwara, Hideki*; Kamoshida, Shuichi*; Anzai, Kiyoshi*
no journal, ,
no abstracts in English
