Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Li, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count:2 Percentile:31.9(Chemistry, Analytical)no abstracts in English
Tsuji, Tomoyuki; Sugitsue, Noritake; Sato, Fuminori; Matsushima, Ryotatsu; Kataoka, Shoji; Okada, Shota; Sasaki, Toshiki; Inoue, Junya
Nihon Genshiryoku Gakkai-Shi ATOMO, 62(11), p.658 - 663, 2020/11
no abstracts in English
Otaka, Toshiki*; Sato, Tatsumi*; Ono, Shimpei; Nagoshi, Kohei; Abe, Ryoji*; Arai, Tsuyoshi*; Watanabe, So; Sano, Yuichi; Takeuchi, Masayuki; Nakatani, Kiyoharu*
Analytical Sciences, 35(10), p.1129 - 1133, 2019/10
Times Cited Count:9 Percentile:40.49(Chemistry, Analytical)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.
Watanabe, Gentaro*; Sonoda, Hidetaka*; Maruyama, Toshiki; Sato, Katsuhiko*; Yasuoka, Kenji*; Ebisuzaki, Toshikazu*
Physical Review Letters, 103(12), p.121101_1 - 121101_4, 2009/09
Times Cited Count:70 Percentile:90.38(Physics, Multidisciplinary)no abstracts in English
Ezure, Toshiki; Sato, Hiroyuki; Kimura, Nobuyuki; Kamide, Hideki
JAEA-Research 2008-093, 34 Pages, 2008/12
Concerning the vortex cavitation in the sodium-cooled fast reactor, basic experiments were performed. The effects of pressure and viscosity on the inception of vortex cavitations were examined in a basic water experiments. As the results, it appeared that the onset value of cavitation coefficient became higher with the increase of the pressure. In addition, it also appeared that the onset value of cavitation coefficient became higher with lower viscosity. However, this difference of onset value for the viscosity became smaller with the increase pressure, and was negligible with the same pressure in the real reactor.
Sato, Hiroyuki; Ezure, Toshiki; Kamide, Hideki
Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), P. 432, 2005/05
A compact sodium reactor is designed as a commercialized fast reactor cycle system. A 1/10th scaled water experiment was performed to optimize upper plenum flow in the reactor vessel, because of high flow velocity resulted from the compacted vessel. In the experiment, vortex cavitation was found at the hot leg inlet because of high velocity in the hot leg pipe (9.4m/s in the design). To evaluate inception cavitation condition of the commercialized reactor, we use the cavitation number k in order to consider the difference of system absolute pressures (0.1MPa in experiment and 0.3MPa in design). The minimum pressure at the vortex center will depend on vortex core radius (size of forced vortex region). It is related to axial velocity gradient and fluid viscosity in theory of the Burger's stretched vortex model. We carried out a basic water experiment to investigate the influence of system pressure and fluid viscosity on the vortex cavitation. The cavitation number at the inception of vortex cavitation slightly increased according to the increase of the system absolute pressure. It means that the vortex cavitation occurs easily under higher-pressure condition as compared with the similar condition of cavitation number with lower pressure. However the increase was less than 30% when the system pressure was varied from 0.1 to 0.3MPa. The influence of fluid viscosity was examined by change of fluid temperature. Velocity distribution around the vortex was also measured to see the structure of vortex.
Watanabe, Gentaro*; Maruyama, Toshiki; Sato, Katsuhiko*; Yasuoka, Kenji*; Ebisuzaki, Toshikazu*
Physical Review Letters, 94(3), p.031101_1 - 031101_4, 2005/01
Times Cited Count:93 Percentile:91.82(Physics, Multidisciplinary)no abstracts in English
Nishimura, Akihiko; Asai, Toshiki; Kurosaka, Keiko; Sato, Masaomi; Hoshiya, Taiji
no journal, ,
Science Outreach Activities on Summer Science Camp has reported. This camp helps the promotion of science education around KANSAI. The camp has both seminars and experiments, which was widely announced by JST home-page since 2007.
Shiine, Yasuharu*; Nishikawa, Hiroyuki*; Mori, Toshiki*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*
no journal, ,
no abstracts in English
Kiriyama, Hiromitsu; Mori, Michiaki; Shimomura, Takuya; Nakai, Yoshiki*; Tanoue, Manabu*; Sasao, Hajime*; Kondo, Shuji; Kanazawa, Shuhei; Ochi, Yoshihiro; Tanaka, Momoko; et al.
no journal, ,
We report on a femtosecond high-intensity OPCPA/Ti:sapphire hybrid laser system that produces more than 30 J broadband output energy, indicating the potential for achieving petawatt-class peak powers. High temporal-contrast of 10 to 10 has been obtained with a near-perfect flat-topped spatial-profile of filling factor 80%. We also present a compact, high-intensity OPCPA/Yb:YAG hybrid laser system that generates 100 mJ output energy with a temporal contrast of better than 10 and good spatial beam quality.
Kotaki, Hideyuki; Kando, Masaki; Pirozhkov, A. S.; Kawase, Keigo*; Esirkepov, T. Z.; Fukuda, Yuji; Kiriyama, Hiromitsu; Okada, Hajime; Daito, Izuru; Kameshima, Takashi*; et al.
no journal, ,
no abstracts in English
Kiriyama, Hiromitsu; Mori, Michiaki; Shimomura, Takuya; Tanoue, Manabu; Kondo, Shuji; Kanazawa, Shuhei; Daito, Izuru; Suzuki, Masayuki*; Okada, Hajime; Ochi, Yoshihiro; et al.
no journal, ,
We describe two specific high intensity laser systems that are being developed in our laboratory for many applications such as high field science, nonlinear optics. We report on an ultra-high intensity petawatt-class Ti:sapphire chirped-pulse amplification laser system that can produce a pulse energy of 18 J with 30 fs pulse duration for studying extremely high intensity laser matter interaction process and a small-scaled Yb:YAG chirped-pulse amplification laser system that can generate a pulse energy of 100 m J of 500 fs pulse duration for compact, high efficiency, high repetition system. We discuss the basic design aspects and present the results from our experimental investigations of these laser systems.
Otaka, Toshiki*; Sato, Tatsumi*; Nakatani, Kiyoharu*; Nagoshi, Kohei*; Abe, Ryoji*; Arai, Tsuyoshi*; Watanabe, So; Sano, Yuichi; Takeuchi, Masayuki
no journal, ,
no abstracts in English
Yomogida, Takumi; Yamada, Shinya*; Ichinohe, Yuto*; Sato, Toshiki*; Hayakawa, Ryota*; Okada, Shinji*; Toyama, Yuichi*; Hashimoto, Tadashi; Noda, Hirofumi*; Isobe, Tadaaki*; et al.
no journal, ,
Biotite is known as a host phase that retains uranium (U) in uranium deposits at Ningyo-Toge and Tono, and it is expected that the distribution of U in biotite will provide insight into the concentration and long-term immobilization of U. However, biotite contains rubidium (Rb), which interferes with X-ray fluorescence analysis, making it difficult to accurately determine the distribution of U-Rb in biotite by measurement using a conventional solid state detector (SSD). In this study, we developed a method to use a transition edge sensor (TES) as a detector in microbeam X-ray fluorescence analysis, which enables us to detect X-ray fluorescence with an energy resolution of about 20 eV and to obtain a Rb K line at 13.373 keV and a U L line at 13.612 keV can be completely separated. Therefore,the developed method enables us to accurately determine the distribution of U-Rb in biotite.
Yomogida, Takumi; Yamada, Shinya*; Ichinohe, Yuto*; Sato, Toshiki*; Hayakawa, Ryota*; Okada, Shinji*; Toyama, Yuichi*; Hashimoto, Tadashi; Noda, Hirofumi*; Isobe, Tadaaki*; et al.
no journal, ,
The reduction of uranium on biotite was studied to obtain insight into the immobilization of uranium in the environment. The chemical species of uranium in biotite were studied using a superconducting transition edge sensor and an X-ray emission spectrometer to remove interference from rubidium in biotite. As a result, the speciation of uranium in biotite collected from former uranium deposits was possible. The XANES spectra of the biotite indicated that the uranium in the biotite was partially reduced.
Kikuchi, Shin; Sato, Rika; Kondo, Toshiki; Umeda, Ryota; Yamano, Hidemasa
no journal, ,
As part of the development of safety design technologies for sodium-cooled fast reactor coupled to thermal energy storage system with sodium-molten salt heat exchanger, we are considering the chemical reactivity between liquid metallic sodium and nitric acid-based molten salt, assuming boundary failure in heat exchangers. In this report, we present the preparation status of fundamental experiment and some results of preliminary experiment.