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Si observed by X-ray absorption spectroscopyNakai, Hirohito*; Ebihara, Takao*; Tsutsui, Satoshi*; Mizumaki, Masaichiro*; Kawamura, Naomi*; Michimura, Shinji*; Inami, Toshiya; Nakamura, Toshiyuki*; Kondo, Akihiro*; Kindo, Koichi*; et al.
Journal of the Physical Society of Japan, 82(12), p.124712_1 - 124712_5, 2013/12
Times Cited Count：9 Percentile：53.63(Physics, Multidisciplinary)The temperature and magnetic field dependences of Yb valence were observed in the heavy fermion compoundYbRhSi by X-ray absorption spectroscopy. The measurements revealed that the Yb valence decreases with decreasing temperature in the range from 200 to 2 K and increases with increasing magnetic field in the range from 0 to 33 T without showing an abrupt change in the Yb valence. The Yb valence is in the range from 2.92 to 2.96 depending on temperature and magnetic field. With respect to the valence being 2.92 at 0 T and 2.93 at 33 T in 2 K, YbRhSi is a valence fluctuation compound and does not reach the integer trivalent state at high magnetic field. These results endorse the conventional knowledge that the valence of Yb is very close to the integer value of 3+, decreases with decreasing temperature, and becomes closer to 3+ with increasing magnetic field.
- and 
-TbAlB
at low temperature and high magnetic fieldsMatsuda, Yasuhiro*; Nakamura, Toshiyuki*; Kuga, Kentaro*; Nakatsuji, Satoru*; Michimura, Shinji*; Inami, Toshiya; Kawamura, Naomi*; Mizumaki, Masaichiro*
Journal of the Korean Physical Society, 62(12), p.1778 - 1781, 2013/06
Times Cited Count：10 Percentile：55.98(Physics, Multidisciplinary)The valence state of Yb ions in - and -YbAlB has been investigated by X-ray absorption and emission spectroscopy at temperatures from 2 to 280 K. It is found that the valence gradually increases with increasing temperature toward 3+ and that the characteristic temperature of the valence fluctuations is about 290 K. We also observe a small increase in the Yb valence (
0.002) in -YbAlB by a magnetic field of 32 T at 40 K.
Nakamura, Toshiyuki*; Matsuda, Yasuhiro*; Her, J.-L.*; Kindo, Koichi*; Michimura, Shinji*; Inami, Toshiya; Mizumaki, Masaichiro*; Kawamura, Naomi*; Suzuki, Motohiro*; Chen, B.*; et al.
Journal of the Physical Society of Japan, 81(11), p.114702_1 - 114702_11, 2012/11
Times Cited Count：11 Percentile：57.56(Physics, Multidisciplinary)The X-ray absorption and magnetic circular dichroism (MCD) spectra at the Yb L
edge were measured in the mixed-valent heavy fermion compound YbAgCu at high magnetic fields and low temperatures. The magnetic-field-temperature (H-T) phase boundary determined by the valence state is in very good agreement with that determined by the magnetization. It is clearly found that the metamagnetism of this compound is due to the field induced valence transition. A distinctive positive peak of the XMCD spectra appears in the vicinity of the white line of the absorption due to Yb
state, while no feature is observed in the XMCD spectra corresponding to the Yb
state. A small negative XMCD peak was observed at a lower energy and was attributed to the quadrupole trasition from theoretical calcuration, which explains its peculicar magnetic field dependence.
-electron itinerancy in CeRuSi by a strong magnetic fieldMatsuda, Yasuhiro*; Nakamura, Toshiyuki*; Her, J. L.*; Michimura, Shinji*; Inami, Toshiya; Kindo, Koichi*; Ebihara, Takao*
Physical Review B, 86(4), p.041109_1 - 041109_4, 2012/07
Times Cited Count：9 Percentile：38.32(Materials Science, Multidisciplinary)The valence state of Ce in a typical heavy fermion compound CeRuSi has been investigated by synchrotron X-ray absorption spectroscopy at 1.8 K in high magnetic fields of up to 40T. The valence was slightly larger than for the pure trivalent state, as expected in heavy fermion compounds, and it decreased toward the trivalent state as the magnetic field was increased. The field-induced valence reduction indicates that the itinerant character of the 4 electrons in CeRuSi was suppressed by a strong magnetic field. The suppression was gradual and showed a characteristic magnetic field dependence, which reflects the metamagnetism around 
8T.
at high Magnetic fieldsMatsuda, Yasuhiro*; Nakamura, Toshiyuki*; Her, J.-L.*; Kindo, Koichi*; Michimura, Shinji*; Inami, Toshiya; Mizumaki, Masaichiro*; Kawamura, Naomi*; Suzuki, Motohiro*; Chen, B.*; et al.
Journal of the Physical Society of Japan, 81(1), p.015002_1 - 015002_2, 2012/01
Times Cited Count：11 Percentile：57.56(Physics, Multidisciplinary)The valence change of Yb ion in YbAgCu was measured by means of X-ray absorption spectroscopy under high magnetic fields up to 35T. The valence state of Yb in YbAgCu at 4.8K significantly increases at the metamagnetic transition. The saturation value of 
at 55T is evaluated as 2.97 using the relation 
at 35T. This value is in good agreement with for the related compound YbInCu at high temperatures and the Yb valence in the localized high-field phase. We conclude that the metamagnetic transition in YbAgCu arises from the valence transition, as theoretically predicted.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Nakamura, Hirofumi; Nagai, Toshihisa; Suto, Toshiyuki; Kosaka, Ichiro; Nakazaki, Katsutoshi; Suto, Shinya; Nakamura, Tomotaka; Nakabayashi, Hiroki; Hayashi, Naoto; Sumida, Daisaku
JAEA-Technology 2008-077, 276 Pages, 2008/12
JAEA-Technology-2008-077.pdf:25.66MB
Japan Atomic Energy Agency (JAEA) has been conducting "Fast Reactor Cycle Technology Development Project (FaCT Project)" for the purposes of researching and developing the technologies for the fast breeder reactor cycle commercialization since Japanese fiscal year (JFY) 2007. Based on the above R&D program for reprocessing system, the engineering-scale hot test would provide demonstration data on the specification, operation and maintenance of the adapted innovative technologies, system and plant. And more, these results would be fed to the design of the demonstration facility planning on the FaCT project road map. This report is the interim report of design studies about the engineering-scale hot test facility and includes not only design of the equipment and facility, but also consideration for design principle, requirements and facility basic planning.
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Sudo, Toshiyuki; ; ; Nojiri, Ichiro; Maki, Akira; Yamanouchi, Takamichi
JNC TN8410 99-003, 69 Pages, 1998/11
As a part of the safety confirmation work of Tokai Reprocessing Plant, the appropriateness was checked on the basic data used in criticality safety and shielding design of early-designed facilities in the plant on the basis of recent knowledge and safety evaluation methods. In the criticality safety design, it was confirmed that critical and subcritical values concerning mass and concentration of U and Pu and equipment dimension were appropriate. In the shielding design, it was found that the relation between shielding thickness and permissible radioactivity might give underestimated results of shielding thickness necessary to limit dose rate to the designated one on some condition. In this cases, however, it was confirmed that necessary shielding thickness has been secured because of the conservative calculation conditions for the real conditions except the operation test laboratory (OTL). However, the amount of radioactivity handled at OTL needs to be limited. From a viewpoint of criticality safety, operational control for U and Pu transfer was also investigated, As a result of it, at the transfer route where erroneous batch-wise transfer of process solution might lead to a criticality accident, the reliability of U and Pu concentration measurement needs to be improved by multiple measurements. At other transfer routes, it was confirmed that single failure of equipment or operation error would not lead to a criticality problem.
Omori, Eiichi; Sudo, Toshiyuki; ; ; ; ; Maki, Akira
JNC TN8410 99-002, 205 Pages, 1998/11
Through the investigation of the cause of the fire and explosion incident at Bituminization Demonstration Facility of JNC Tokai Works, the lesson learned is that the safety assessment is necessary even for the licensed facilities by recent knowledge. The safety assessment has been conducted for the facilities in Tokai Reprocessing Plant by recent knowledge and operational experience. This report describes the review of the design data for safety assessment of Tokai Reprocessing Plant. The spent fuel inventory, the radio activity balance in the processes, the inventory contained in each equipment, and the evaluation method of public dose were evaluated with the recent data, the new calculation method and the data obtained through the plant operation. The important equipments were selected for safety assessment as for the public dose. The hydrogen generation from radiolysis of solution was also evaluated, and the hydrogen concentration in each equipment was kept lower than the flammable limit except several equipments that are to be improved.
Kobayashi, Hitoshi*; Kurihara, Toshikazu*; Matsumoto, Hiroshi*; Yoshioka, Masakazu*; Matsumoto, Noriyuki*; Kumada, Hiroaki*; Matsumura, Akira*; Sakurai, Hideyuki*; Hiraga, Fujio*; Kiyanagi, Yoshiaki*; et al.
no journal, ,
no abstracts in English
