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Ishida, Tsuyoshi; Nakashima, Shinichi; Kondo, Shinji; Hayashibara, Kenichi; Yamada, Shigeki*; Okamoto, Ryo*; Nakamura, Hironobu
Dai-44-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2023/11
no abstracts in English
Sasaki, Ichiro; Watanabe, Shigeki; Ohshima, Yasuhiro; Sugo, Yumi; Yamada, Keiichi*; Hanaoka, Hirofumi*; Ishioka, Noriko
Peptide Science 2015, p.243 - 246, 2016/03
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Maeda, Eita*; Watanabe, Shigeki; Hashimoto, Kazuyuki; Ishioka, Noriko; Makii, Hiroyuki; Toyoshima, Atsushi; Yamada, Norihiro*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 304(3), p.1077 - 1083, 2015/06
Times Cited Count:9 Percentile:60.04(Chemistry, Analytical)Production cross sections of astatine isotopes At in the 29-57 MeV Li induced reaction with Pb target have been measured by - and -ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of Li + Pb. Considerably small experimental cross sections of At and At compared with the calculation were clearly observed at incident energies higher than 44 MeV, indicating that the effects of breakup reaction play a role. A chemical separation of astatine from an irradiated lead target has been studied with a dry-distillation method. A complementary way to produce astatine isotopes has been developed.
Hanaoka, Hirofumi*; Ohshima, Yasuhiro; Suzuki, Yurika*; Yamaguchi, Aiko*; Watanabe, Shigeki; Uehara, Tomoya*; Nagamori, Shushi*; Kanai, Yoshikatsu*; Ishioka, Noriko; Tsushima, Yoshito*; et al.
Journal of Nuclear Medicine, 56(5), p.791 - 797, 2015/05
Times Cited Count:18 Percentile:62.21(Radiology, Nuclear Medicine & Medical Imaging)Sugo, Yumi; Sasaki, Ichiro; Watanabe, Shigeki; Ohshima, Yasuhiro; Ishioka, Noriko
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 100, 2015/03
Sasaki, Ichiro; Hanaoka, Hirofumi*; Yamada, Keiichi*; Watanabe, Shigeki; Sugo, Yumi; Ohshima, Yasuhiro; Suzuki, Hiroyuki; Ishioka, Noriko
Peptide Science 2014, p.257 - 260, 2015/03
Sugo, Yumi; Sasaki, Ichiro; Watanabe, Shigeki; Ohshima, Yasuhiro; Ishioka, Noriko
Peptide Science 2013, p.355 - 358, 2014/03
Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Togashi, Tadashi*; Fukami, Kenji*; et al.
Journal of Physics B; Atomic, Molecular and Optical Physics, 46(16), p.164006_1 - 164006_6, 2013/08
Times Cited Count:3 Percentile:18.94(Optics)By introducing 13th- (61.7 nm) and 15th-order harmonics (53.4 nm) of femtosecond laser pulses at 800 nm into an undulator of SCSS (SPring-8 Compact SASE Source) test accelerator at RIKEN, these harmonic pulses were amplified by a factor of more than 10 with a high contrast ratio through the interaction between accelerated electron bunches and the harmonic pulses. From numerical simulations of the amplification processes of high-order harmonic pulses in the undulator, optimum conditions of the electron bunch duration interacting with the high-order harmonic pulses were investigated for generating full-coherent and intense pulses in the extreme ultraviolet wavelength region.
Ogawa, Kanade*; Sato, Takahiro*; Matsubara, Shinichi*; Okayasu, Yuichi*; Togashi, Tadashi*; Watanabe, Takahiro*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; et al.
Proceedings of 10th Conference on Lasers and Electro-Optics Pacific Rim and 18th OptoElectronics and Communications Conference and Photonics in Switching 2013 (CLEO-PR & OECC/PS 2013) (USB Flash Drive), 2 Pages, 2013/06
no abstracts in English
Oshima, Takeshi; Deki, Manato; Makino, Takahiro; Iwamoto, Naoya; Onoda, Shinobu; Hirao, Toshio*; Kojima, Kazutoshi*; Tomita, Takuro*; Matsuo, Shigeki*; Hashimoto, Shuichi*
AIP Conference Proceedings 1525, p.654 - 658, 2013/04
Times Cited Count:0 Percentile:0.05(Physics, Applied)Metal-Oxide-Semiconductor (MOS) capacitors were fabricated on n-type 4H-SiC epitaxial layers, and the leakage current through the gate oxide during heavy ion irradiation was investigated in order to evaluate dielectric breakdown induced by heavy ions (Single Event Gate Rupture: SEGR). The gate oxide at thickness ranges between 60 and 80 nm was formed using pyrogenic oxidation at 1100 C for 60 min. Circular electrodes with 180 diameter were formed using Al evaporation and a lift-off technique. The leakage current observed through the gate oxide was monitored during 18 MeV oxygen (O) or nickel (Ni) ions. As a result, although no significant difference in the value of the electric field at the dielectric breakdown (around 8.2 MV/cm) was observed between non-irradiated and 18 MeV-O irradiated samples, the value decreased to be 7.3 MV/cm in the case of 18 MeV-Ni ion incidence. The Linier Energy Transfer (LET) for 18 MeV-O is 7 MeV cm/mg, and this value is smaller than that for 18 MeV-Ni (24 MeV cm/mg). Also, 18 MeV-Ni ions deposit energy in narrower regions than 18 MeV-O ions. Thus, it can be concluded that the high density of charge induced by 18 MeV-Ni ions triggers SEGR in SiC MOS capacitors.
Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Hara, Toru*; et al.
Proceedings of Ultrafast Optics IX (CD-ROM), 2 Pages, 2013/03
We have demonstrated free-electron laser radiation seeded by high-order harmonics in the extreme-ultraviolet region. Strong enhancement of the radiation intensity by a factor of 104 was observed with timing control of an electro-optical sampling technique.
Niwa, Hideharu*; Saito, Makoto*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Moriya, Shogo*; Matsubayashi, Katsuyuki*; Nabae, Yuta*; Kuroki, Shigeki*; Ikeda, Takashi; et al.
Journal of Power Sources, 223, p.30 - 35, 2013/02
Times Cited Count:18 Percentile:50.62(Chemistry, Physical)To design non-platinum, inexpensive, but high performance carbon-based cathode catalysts for polymer electrolyte fuel cells, it is important to elucidate the active site for oxygen reduction reaction (ORR). However, it is difficult to directly identify the active site by applying conventional structural or electronic probes to such complex systems. Here, we used C 1 X-ray absorption spectroscopy (XAS) to observe electronic structure of carbon in iron phthalocyanine-based catalysts, and found a signature of edge exposure below the edge, whose intensity is well correlated with the ORR activity. These results demonstrate that C 1 XAS can be used to characterize the ORR activity of carbon-based cathode catalysts in terms of the edge exposure.
Watanabe, Shigeki; Yamada, Keiichi*; Tsukui, Narutaka*; Hanaoka, Hirofumi*; Ohshima, Yasuhiro; Yamaguchi, Aiko*; Oku, Hiroyuki*; Ishioka, Noriko
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 88, 2013/01
Hanaoka, Hirofumi*; Watanabe, Shigeki; Tominaga, Hideyuki*; Ohshima, Yasuhiro; Watanabe, Satoshi; Yamada, Keiichi*; Iida, Yasuhiko*; Ishioka, Noriko; Endo, Keigo*
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 89, 2013/01
no abstracts in English
Kiuchi, Hisao*; Niwa, Hideharu*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Chokai, Masayuki*; Nabae, Yuta*; Kuroki, Shigeki*; Kakimoto, Masaaki*; Ikeda, Takashi; et al.
Electrochimica Acta, 82(1), p.291 - 295, 2012/10
Times Cited Count:14 Percentile:34.15(Electrochemistry)We study the characteristics of oxygen adsorption on metal-free carbon-based cathode catalysts derived from nitrogen-containing polyamide (PA) and nitrogen-free phenolic resin (PhRs). Electrochemical analysis and Raman spectroscopy showed higher 2-electron oxygen reduction reaction (ORR) activity and more defect sites in PA than PhRs. The increase in the amount of adsorbed oxygen in PA was also identified by oxygen adsorption isotherms. X-ray photoelectron spectroscopy reveals that graphite-like nitrogen contributes to oxygen adsorption and C=O components are dominant in PA. These experimental results indicate that the adsorbed C=O components near the graphite-like nitrogen can be assigned as active sites for 2-electron ORR.
Kawamura, Hideyuki; Kobayashi, Takuya; Furuno, Akiko; In, Teiji*; Ishikawa, Yoichi*; Nakayama, Tomoharu*; Shima, Shigeki*; Awaji, Toshiyuki*
Reports of Research Institute for Applied Mechanics, Kyushu University, (143), p.111 - 117, 2012/09
Because of the Fukushima Dai-ichi Nuclear Power Plant disaster, some radionuclides were released into the ocean from the Fukushima Dai-ichi Nuclear Power Plant. In response to this situation, numerical experiments were carried out at Japan Atomic Energy Agency using an oceanic dispersion model and an ocean general circulation model to estimate an effect of the radionuclides on marine environment. It was suggested that the radionuclides deposited from the atmosphere mainly in the middle of March after the disaster spread over a comparatively wide area of the Pacific Ocean east of Japan. On the other hand the radionuclides directly released into the ocean from the Fukushima Dai-ichi Nuclear Power Plant were carried along the coast and then spread along the Kuroshio extension.
Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Hara, Toru*; et al.
Proceedings of 11th International School and Symposium on Synchrotron Radiation in Natural Science (ISSRNS 2012), p.1 - 21, 2012/05
The 13th harmonic of a Ti:sapphire laser has been significantly amplified with the SCSS test accelerator. The temporal and spatial overlap of the electron beam and the high harmonic radiation were precisely tuned for achieving the seeded free electron laser operation. With numerical simulation the present HH-seeded FEL scheme could readily be applied to the wavelength region down to 10 nm.
Murakami, Hiroshi; Toyota, Yuji*; Nishi, Takaki*; Nashima, Shigeki*
Chemical Physics Letters, 519-520, p.105 - 109, 2012/01
Times Cited Count:19 Percentile:57.28(Chemistry, Physical)no abstracts in English
Ohshima, Yasuhiro; Hanaoka, Hirofumi*; Watanabe, Shigeki; Sugo, Yumi; Watanabe, Satoshi; Tominaga, Hideyuki*; Oriuchi, Noboru*; Endo, Keigo*; Ishioka, Noriko
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 91, 2012/01
Eto, Masao*; Kamishima, Yoshio*; Okamura, Shigeki*; Watanabe, Osamu*; Oyama, Kazuhiro*; Negishi, Kazuo; Kotake, Shoji*; Sakamoto, Yoshihiko; Kamide, Hideki
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles (FR 2009) (CD-ROM), 10 Pages, 2012/00
In the JSFR design, the diameter of the Reactor Vessel (RV) shall be minimized and the reactor internal structures shall be simplified for reduction in construction cost. The reduction in the RV diameter is achieved by adopting an advanced refueling system and the hot RV with high temperature wall. The flow velocity in the reactor upper plenum increases because the diameter of the RV is decreased. As the result, the coolant flow field in reactor upper plenum is severe. The optimization of the coolant flow field in the reactor upper plenum was carried out for prevention the cover gas entrainment and the vortex cavitations at the hot leg intake. In addition, structural integrities for seismic loadings and thermal loadings were evaluated because the design seismic loading was highly increased and the vessel wall is directly exposed to the thermal transients of the upper plenum. This paper describes the characteristics and the results of the design study of the reactor system.