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Nakashima, Nobuaki*; Yatsuhashi, Tomoyuki*; Sakota, Kenji*; Iwakura, Izumi*; Hashimoto, Sena*; Yokoyama, Keiichi; Matsuda, Shohei
Chemical Physics Letters, 752, p.137570_1 - 137570_5, 2020/08
Times Cited Count：1 Percentile：4.74(Chemistry, Physical)Photo-redox reactions between Eu
and Eu
ions are induced by laser irradiation in alcoholic solution. Efficiency, wavelength dependence, and laser-power dependence are investigated with three different lasers. Nano second laser pulses at a wavelength of 308 nm is found to cause one-photon redox reactions with a quantum yield around 0.5. Nano second laser pulses at a wavelength of 394 nm induces two-photon reduction of Eu to form Eu. When the pulse energy is 5 mJ, the quantum yield is measured to be 0.015. Although the quantum yield is one order of magnitude lower than that of the one photon reduction, reduction phenomena can be easily observed under the moderate laser field strength. Because of the two-photon nature, there should be a room to improve the efficiency by increasing the laser field strength.
Ohshima, Hiroyuki; Uwaba, Tomoyuki; Hashimoto, Akihiko*; Imai, Yasutomo*; Ito, Masahiro*
AIP Conference Proceedings 1702, p.040011_1 - 040011_4, 2015/12
A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies of sodium-cooled fast reactors under various operating conditions including fuel deformation. This paper gives a summary of numerical methods of component programs of the system and their validation studies.
Tc-MDP using Tc separated from 
Mo produced by 
Mo(
,2)MoNagai, Yasuki; Hatsukawa, Yuichi; Kin, Tadahiro; Hashimoto, Kazuyuki; Motoishi, Shoji; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Yuichi*; Kawauchi, Yukimasa*; et al.
Journal of the Physical Society of Japan, 80(8), p.083201_1 - 083201_4, 2011/08
Times Cited Count：15 Percentile：65.13(Physics, Multidisciplinary)We have for the first time succeeded to separate Tc from a Mo oxide sample irradiated by accelerator neutrons, and to formulate Tc-methylene diphosphonate (Tc-MDP). Mo, the mother nuclide of Tc, was produced by the Mo(,2)Mo reaction using about 14 MeV neutrons provided at the Fusion Neutronics Source of Japan Atomic Energy Agency. The Tc was separated from Mo by the sublimation method, and its radionuclide purity was confirmed to be higher than 99.99%. The labeling efficiency of Tc-MDP was shown to be higher than 99%. These values exceed the United States Pharmacopeia requirements for a fission product, Mo. Consequently, a Tc radiopharmaceutical preparation formed by using the mentioned Mo can be a promising substitute for the fission product Mo. A longstanding problem to ensure a reliable and constant supply of Mo in Japan can be partially mitigated.
Asano, Yoshihiro; Matsumura, Toru; Chiba, R.*; Hashimoto, Tomoyuki*; Miura, Akio*; Shimizu, Hajime*; Tajima, Yasuhisa*; Yoshida, H.*
Nuclear Instruments and Methods in Physics Research A, 451(2), p.658 - 696, 2000/11
no abstracts in English
Ohshima, Hiroyuki; Uwaba, Tomoyuki; Hashimoto, Akihiko*; Imai, Yasutomo*
no journal, ,
A numerical simulation system is being developed in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel subassemblies of sodium-cooled fast reactors under various operating conditions such as normal operation, transient condition or deformed geometry condition from the viewpoint of the assessment of fuel pin structure integrity. As a part of this simulation system development, a coupling method of thermal-hydraulic analysis with fuel deformation analysis was implemented and was applied to a high burn-up fuel assembly analysis for the method verification.
Ohshima, Hiroyuki; Uwaba, Tomoyuki; Hashimoto, Akihiko*
no journal, ,
Adoption of higher burn-up core can be considered as one of effective methods to enhance economic competitiveness for the commercialization of sodium-cooled fast reactors and it becomes possible with evaluating and confirming structural integrity of fuel assemblies under high burn-up conditions. A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency (JAEA) in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies under various operating conditions. In this paper, an analysis method of thermal-hydraulics in a wire-wrapped and deformed fuel pin bundle using two kinds of component programs of the numerical simulation system and its application to an irradiated fuel assembly analysis are described.
