Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Hayashi, Koichi*; Lederer, M.*; Fukumoto, Yohei*; Goto, Masashi*; Yamamoto, Yuta*; Happo, Naohisa*; Harada, Masahide; Inamura, Yasuhiro; Oikawa, Kenichi; Oyama, Kenji*; et al.
Applied Physics Letters, 120(13), p.132101_1 - 132101_6, 2022/03
Times Cited Count:0 Percentile:0(Physics, Applied)Ueta, Shohei; Mizuta, Naoki; Fukaya, Yuji; Goto, Minoru; Tachibana, Yukio; Honda, Masaki*; Saiki, Yohei*; Takahashi, Masashi*; Ohira, Koichi*; Nakano, Masaaki*; et al.
Nuclear Engineering and Design, 357, p.110419_1 - 110419_10, 2020/02
Times Cited Count:1 Percentile:11.8(Nuclear Science & Technology)The concept of a plutonium (Pu) burner HTGR is proposed to incarnate highly-effective Pu utilization by its inherent safety features. The security and safety fuel (3S-TRISO fuel) employs the coated fuel particle with a fuel kernel made of plutonium dioxide (PuO) and yttria stabilized zirconia (YSZ) as an inert matrix. This paper presents feasibility study of Pu burner HTGR and R&D on the 3S-TRISO fuel.
Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Times Cited Count:18 Percentile:74.14(Physics, Multidisciplinary)Excitation functions of quasielastic scattering cross sections for the Ca + Pb, Ti + Pb, and Ca + Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Goto, Minoru; Demachi, Kazuyuki*; Ueta, Shohei; Nakano, Masaaki*; Honda, Masaki*; Tachibana, Yukio; Inaba, Yoshitomo; Aihara, Jun; Fukaya, Yuji; Tsuji, Nobumasa*; et al.
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.507 - 513, 2015/09
A concept of a plutonium burner HTGR named as Clean Burn, which has a high nuclear proliferation resistance, had been proposed by Japan Atomic Energy Agency. In addition to the high nuclear proliferation resistance, in order to enhance the safety, we propose to introduce PuO-YSZ TRISO fuel with ZrC coating to the Clean Burn. In this study, we conduct fabrication tests aiming to establish the basic technologies for fabrication of PuO-YSZ TRISO fuel with ZrC coating. Additionally, we conduct a quantitative evaluation of the security for the safety, a design of the fuel and the reactor core, and a safety evaluation for the Clean Burn to confirm the feasibility. This study is conducted by The University of Tokyo, Japan Atomic Energy Agency, Fuji Electric Co., Ltd., and Nuclear Fuel Industries, Ltd. It was started in FY2014 and will be completed in FY2017, and the first year of the implementation was on schedule.
Kaji, Daiya*; Morimoto, Koji*; Wakabayashi, Yasuo*; Takeyama, Mirei*; Yamaki, Sayaka*; Tanaka, Kengo*; Haba, Hiromitsu*; Huang, M.*; Murakami, Masashi*; Kanaya, Jumpei*; et al.
JPS Conference Proceedings (Internet), 6, p.030107_1 - 030107_4, 2015/06
Performance of the new gas-filled recoil ion separator GARIS-II was investigated using asymmetric Ne-induced fusion reactions. The use of He-H mixture gas for the gas-filled magnet significantly reduced background scattered particles detected at the focal-plane Si detector, and increased a transmission of the asymmetric reaction products. A target-identification system was newly installed for efficient measurements of excitation functions without changing beam energy nor target.
Murakami, Masashi*; Goto, Shinichi*; Murayama, Hirofumi*; Kojima, Takayuki*; Kudo, Hisaaki*; Kaji, Daiya*; Morimoto, Koji*; Haba, Hiromitsu*; Kudo, Yuki*; Sumita, Takayuki*; et al.
Physical Review C, 88(2), p.024618_1 - 024618_8, 2013/08
Times Cited Count:16 Percentile:69.99(Physics, Nuclear)Production cross sections of Rf isotopes in the Cm + O reaction were measured at the beam energy range of 88.2 to 101.3 MeV by use of a gas-filled recoil ion separator. The excitation functions of Rf, Rf, and Rf were obtained together with those of spontaneously fissioning nuclides which have few-second half-lives and have been assigned to Rf and a longer-lived state of Rf. The excitation function of few-second spontaneously fissioning nuclide exhibited the maximum cross section at the O beam energy of 94.8 MeV. The shape of the excitation function was almost the same as that of Rf, whereas it was quite different from those of Rf and Rf. A few-second spontaneously fissioning nuclide previously reported as Rf and Rf observed inCm + O reaction was identified as Rf.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.
Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10
Times Cited Count:167 Percentile:97.31(Physics, Multidisciplinary)An isotope of the 113th element, 113, was produced in a nuclear reaction with a Zn beam on a Bi target. We observed six consecutive decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of Db and Lr both in decay energies and decay times. This indicates that the present decay chain consisted of 113, Rg (Z = 111), Mt (Z = 109), Bh (Z = 107), Db (Z = 105), and Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope 113, of the 113th element.
Li, Z.*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Sato, Nozomi; Kikuchi, Takahiro; Nagame, Yuichiro; Schdel, M.; Pershina, V.*; et al.
Radiochimica Acta, 100(3), p.157 - 164, 2012/03
Times Cited Count:14 Percentile:68.93(Chemistry, Inorganic & Nuclear)Nishinaka, Ichiro; Kasamatsu, Yoshitaka*; Tanikawa, Masashi*; Goto, Shinichi*; Asai, Masato
Proceedings in Radiochemistry, 1(1), p.117 - 121, 2011/09
Unexpected steep falloff of fusion cross sections has recently been observed in heavy-ion fusion reactions at deep sub-barrier energies. In this study the fusion-fission cross sections for F+Bi at sub-barrier energies were determined by a radiochemical method in order to study sub-barrier fusion hindrance. We will discuss the sub-barrier fusion hindrance in heavy-mass systems, comparing the theoretical calculations and the systematics.
Nishinaka, Ichiro; Tanikawa, Masashi*; Goto, Shinichi*; Nishio, Katsuhisa; Asai, Masato; Tsukada, Kazuaki; Nagame, Yuichiro; Kudo, Hisaaki*
Nuclear Physics A, 805, p.434 - 436, 2008/00
The aim of this work is to study how shell effects of fissioning nuclei and fission fragments are responsible for deformation and mass division during descent from the saddle point to scission. We studied in detail excitation energy dependence of mass and total kinetic energy distributions in the fission of + U at incident beam energies of 10.0, 11.5 and 13.0 MeV. For the asymmetric mass division in the fission for both uranium isotopes, the obtained yield at 132 with the spherical shell of = 82 increases more largely with increasing excitation energy than that at 143 with deformed shell of = 86-88. The present excitation energy dependence shows the opposite trend observed in the thermal neutron induced fission and cold fission of actinides. We will discuss the shell effects on excitation energy dependence of fragment mass and total kinetic energy distributions in fission.
Kakurai, Kazuhisa; Osakabe, Toyotaka; Goto, Kenji*; Osawa, Akira*; Fujisawa, Masashi*; Tanaka, Hidekazu*
Physica B; Condensed Matter, 385-386(Part 1), p.450 - 452, 2006/11
Times Cited Count:1 Percentile:6.63(Physics, Condensed Matter)KCuCl and TlCuCl are singlet ground state systems with excitation gap of 31K and 7.7K, respectively. The origin of the spin gap is the strong antiferromagnetic spin dimer of the chemical CuCl unit. These spin dimers are weakly coupled three dimensionally via non-frustrating inter dimer exchanges. The magnetization measurements under applied hydrostatic pressure show the existence of the magnetic order above certain critical pressure Pc=8.8 kbar and 0.42 kbar, respectively. We report on the elastic neutron scattering results of the pressure induced magnetic ordering in these quantum systems. The observed magnetic structures and the possible role of the spin-lattice coupling in the spin reorientation in TlCuCl3 under pressure will be discussed.
Goto, Kenji; Fujisawa, Masashi*; Tanaka, Hidekazu*; Uwatoko, Yoshiya*; Osawa, Akira*; Osakabe, Toyotaka; Kakurai, Kazuhisa
Journal of the Physical Society of Japan, 75(6), p.064703_1 - 064703_7, 2006/06
Times Cited Count:30 Percentile:76.29(Physics, Multidisciplinary)Magnetization and neutron elastic scattering experiments under hydrostatic pressure were performed on KCuCl, which is a three-dimensionally coupled spin dimer system with a gapped ground state. It was found that the intradimer interaction decreases with increasing hydrostatic pressure, while the sum of the interdimer interactions increases. This leads to the shrinkage of the spin gap. A quantum phase transition from a gapped state to an antiferromagnetic state occurs at Pc8.2 kbar. For PPc, magnetic reflections were observed at reciprocal lattice points equivalent to those for the lowest magnetic excitation at zero temperature. This confirms that the spin gap decreases and closes under applied pressure.
Sakata, Osami*; Furukawa, Yukito*; Goto, Shunji*; Mochizuki, Tetsuro*; Uruga, Tomoya*; Takeshita, Kunikazu*; Ohashi, Haruhiko*; Ohata, Toru*; Matsushita, Tomohiro*; Takahashi, Sunao*; et al.
Surface Review and Letters, 10(2&3), p.543 - 547, 2003/04
Times Cited Count:142 Percentile:96.4(Chemistry, Physical)The main components of a new beamline for surface and interface crystal structure determination at SPring-8 are briefly described. Stages for the beamline monochromator are modified for making an incident X-ray intensity more stable for surface X-ray experiments. Absolute photon flux densities were measured with an incident photon energy. A new ultrahigh vacuum system is introduced with preliminary X-ray measurements from an ordered oxygen on Pt(111) surface.
Goto, Shinichi*; Kaji, D.*; Nishinaka, Ichiro; Nagame, Yuichiro; Ichikawa, Shinichi; Tsukada, Kazuaki; Asai, Masato; Haba, Hiromitsu; Mitsuoka, Shinichi; Nishio, Katsuhisa; et al.
Journal of Radioanalytical and Nuclear Chemistry, 255(1), p.73 - 76, 2003/01
Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)no abstracts in English
Zhao, Y. L.*; Nishinaka, Ichiro; Nagame, Yuichiro; Tsukada, Kazuaki; Sueki, Keisuke*; Goto, Shinichi*; Tanikawa, Masashi*; Nakahara, Hiromichi*
Journal of Radioanalytical and Nuclear Chemistry, 255(1), p.67 - 72, 2003/01
Times Cited Count:4 Percentile:31.59(Chemistry, Analytical)no abstracts in English
Zhao, Y. L.*; Nagame, Yuichiro; Nishinaka, Ichiro; Tsukada, Kazuaki; Sueki, Keisuke*; Nakahara, Hiromichi*; Goto, Shinichi*; Tanikawa, Masashi*
Journal of Nuclear Science and Technology, 39(Suppl.3), p.30 - 33, 2002/11
no abstracts in English
Zhao, Y. L.*; Nishinaka, Ichiro; Nagame, Yuichiro; Tsukada, Kazuaki; Sueki, Keisuke*; Tanikawa, Masashi*; Goto, Shinichi*; Nakahara, Hiromichi*
Journal of Nuclear and Radiochemical Sciences, 3(1), p.103 - 107, 2002/06
no abstracts in English
Nagame, Yuichiro; Zhao, Y.*; Nishinaka, Ichiro; Goto, Shinichi*; Kaji, D.*; Tanikawa, Masashi*; Tsukada, Kazuaki; Asai, Masato; Haba, Hiromitsu; Sakama, Minoru*; et al.
Radiochimica Acta, 89(11-12), p.681 - 688, 2002/02
Times Cited Count:3 Percentile:27.07(Chemistry, Inorganic & Nuclear)no abstracts in English
Nagame, Yuichiro; Zhao, Y.*; Nishinaka, Ichiro; Goto, Shinichi; Tanikawa, Masashi*; Tsukada, Kazuaki; Asai, Masato; Haba, Hiromitsu; Sakama, Minoru; Ichikawa, Shinichi; et al.
Heavy Ion Physics, 13(1-3), p.121 - 131, 2001/05
Times Cited Count:0 Percentile:0.01(Physics, Nuclear)no abstracts in English
Nagame, Yuichiro; Nishinaka, Ichiro; Zhao, Y. L.*; Tsukada, Kazuaki; Ichikawa, Shinichi; Ikezoe, Hiroshi; Tanikawa, Masashi*; Otsuki, Tsutomu*; Oura, Yasutsugu*; Sueki, Keisuke*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 239(1), p.97 - 101, 1999/00
Times Cited Count:4 Percentile:34.76(Chemistry, Analytical)no abstracts in English