Sonoda, Tetsu*; Iimura, Hideki; Reponen, M.*; Wada, Michiharu*; Katayama, Ichiro*; Sonnenschein, V.*; Takamatsu, Takahide*; Tomita, Hideki*; Kojima, Takao*
Nuclear Instruments and Methods in Physics Research A, 877, p.118 - 123, 2018/01
In order to produce low-energy RI beams at RIKEN RIBF, a laser ion source, PALIS, is under construction. This ion source is based on resonance ionization of RI atoms captured in Ar gas. Because the ion source is located 70m away from lasers, we have developed an optical system for laser beam transport. This system can be controlled remotely when the ion source is not accessible because of high radiation level. The position of laser beam after transport is reasonably stable, and the transport efficiency is about 50%.
Ishiyama, Hironobu*; Jeong, S.-C.*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Katayama, Ichiro*; Osa, Akihiko; Otokawa, Yoshinori; et al.
Japanese Journal of Applied Physics, 53(11), p.110303_1 - 110303_4, 2014/11
Iguchi, Masahide; Saito, Toru; Kawano, Katsumi; Chida, Yutaka; Nakajima, Hideo; Ogawa, Tsuyoshi*; Katayama, Yoshinori*; Ogata, Hiroshige*; Minemura, Toshiyuki*; Tokai, Daisuke*; et al.
Fusion Engineering and Design, 88(9-10), p.2520 - 2524, 2013/10
ITER TFC structures are large welding structures made of heavy thick stainless steels. JAEA plans to apply narrow gap TIG welding with FMYJJ1 which is full austenitic stainless filler material to manufacture TFC structure. FMYJJ1 is specified in "Codes for Fusion Facilities -Rules on Superconducting Magnet Structure (2008)". In order to evaluate effect of base material combinations and thickness of welded joint on tensile properties at 4 K, tensile tests were conducted at 4 K by using tensile specimens taken from 40 mm thickness weld joints of four combinations and 200 mm thickness ones of two combinations of base materials. These weld joints were manufactured by one side narrow gap TIG welding with FMYJJ1. As the results, it was confirmed that yield and tensile strengths of welded joint at 4K were decreased with decreasing of nitrogen of base material, and there were no large distribution of strengths at 4 K along the thickness of welded joints of 200 mm thickness.
Hirayama, Yoshikazu*; Mihara, Mototsugu*; Watanabe, Yutaka*; Jeong, S. C.*; Miyatake, Hiroari*; Momota, Sadao*; Hashimoto, Takashi*; Imai, Nobuaki*; Matsuta, Kensaku*; Ishiyama, Hironobu*; et al.
European Physical Journal A, 48(5), p.54_1 - 54_10, 2012/05
Okada, Masashi*; Niki, Kazuaki*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Ishiyama, Hironobu*; Jeong, S. C.*; Katayama, Ichiro*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Watanabe, Yutaka*; et al.
Physical Review Special Topics; Accelerators and Beams, 15(3), p.030101_1 - 030101_10, 2012/03
Iguchi, Masahide; Chida, Yutaka; Nakajima, Hideo; Ogawa, Tsuyoshi*; Katayama, Yoshinori*; Ogata, Hiroshige*; Minemura, Toshiyuki*; Miyabe, Keisuke*; Tokai, Daisuke*; Niimi, Kenichiro*
Teion Kogaku, 47(3), p.193 - 199, 2012/03
Japan Atomic Energy Agency (JAEA) has conducted qualification and rationalization activities in Japan in order to rationalize manufacturing procedure of ITER Toroidal Field (TF) coil structures. The activities included qualification of structural materials and qualification of welding procedure according to Japan Society of Mechanical Engineers (JSME) code constituted for fusion devices, demonstration of the manufacturing method and procedures through full-scale segments of TF coil structure. From results of these activities, JAEA confirmed applicability of JSME code to actual series TF coil structures as quality control method hence the quality of structural materials and weld joints of Gas Tungsten Arc Welding (GTAW) were satisfied ITER requirement. In addition, JAEA obtained knowledge of welding deformation of actual TF coil structures. This paper describes results of these qualification and development activities for TF coil structure.
Yoshiasa, Akira*; Murai, Keiichiro*; Arima, Hiroshi*; Katayama, Yoshinori
International Journal of Modern Physics B, 25(31), p.4159 - 4162, 2011/12
Precise structure analyses of advanced materials under pressure were performed using each advantage of X-ray absorption fine structure (XAFS) and diffraction methods. Measurements were performed in-situ under pressure and temperature using a large-volume multi-anvil pressure apparatus and synchrotron radiation. XAFS spectra are useful for phase study under high temperature and high pressure. The XAFS Debye-Waller factor provides anharmonic effective pair potential with a pressure-dependent and temperature-independent shape. The phonon energies and anharmonicity are affected largely by the change in local structure and bonding character.
Kameo, Yutaka; Ishimori, Kenichiro; Haraga, Tomoko; Shimada, Asako; Katayama, Atsushi; Nakashima, Mikio*; Takahashi, Kuniaki
Nippon Genshiryoku Gakkai Wabun Rombunshi, 10(3), p.216 - 225, 2011/09
Analytical methods have been developed for simple and rapid determination of radioactive nuclides, which are selected as important nuclides for safety assessment of disposal of wastes generated from research facilities. We advanced the development of a high-efficiency non-destructive measurement technique for -ray emitting nuclides, simple and rapid methods for pretreatment of hard-to dissolve samples and subsequent radiochemical separations, and rapid determination methods for long-lived nuclides. In order to establish a system to analyze the important nuclides in various kinds of samples, actual radioactive wastes such as concentrated liquid waste, activated concrete, and metal pipes, were analyzed by the present method. The results showed that the present method was well suited for a rapid and simple determination of low-level radioactive wastes generated from research facilities.
Kameo, Yutaka; Shimada, Asako; Ishimori, Kenichiro; Haraga, Tomoko; Katayama, Atsushi; Hoshi, Akiko; Nakashima, Mikio
JAEA-Technology 2009-051, 81 Pages, 2009/10
Simple and rapid determination methods were developed for an evaluation of important nuclides, U, and Th in wastes generated from research facilities at Nuclear Science Research Institute and Oarai Research and Development Center. The present methods were assumed to apply to solidified products made from miscellaneous wastes by plasma melting at the Advanced Volume Reduction Facilities. In order to reduce costs of radiochemical analysis and to establish a routine analytical system, counting efficiency of non-destructive -ray measurements was improved, and times for pretreatment of solidified product samples and subsequent radiochemical separations were shortened. In addition to this, rapid and high sensitive detection methods were developed for a determination of long-lived nuclides. The present paper describes guidelines for the determination of radionuclides in the low-level radioactive wastes by using the present simple and rapid methods.
Katayama, Naoyuki*; Uchida, Masaya*; Hashizume, Daisuke*; Niitaka, Seiji*; Matsuno, Jobu*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Takeshita, Nao*; Gauzzi, A.*; et al.
Physical Review Letters, 103(14), p.146405_1 - 146405_4, 2009/10
We investigate LiVS and LiVSe with a triangular lattice as itinerant analogues of LiVO known for the formation of a valence-bond solid (VBS) state out of an S = 1 frustrated magnet. LiVS, which is located at the border between a metal and a correlated insulator, shows a first order transition from a paramagnetic metal to a VBS insulator at T 305 K upon cooling. The presence of a VBS state in the close vicinity of insulator-metal transition may suggest the importance of itinerancy in the formation of a VBS state. We argue that the high temperature metallic phase of LiVS has a pseudogap, likely originating from the VBS fluctuation. LiVSe was found to be a paramagnetic metal down to 2 K.
Jeong, S.-C.*; Katayama, Ichiro*; Kawakami, Hirokane*; Watanabe, Yutaka*; Ishiyama, Hironobu*; Imai, Nobuaki*; Hirayama, Yoshikazu*; Miyatake, Hiroari; Sataka, Masao; Sugai, Hiroyuki; et al.
Japanese Journal of Applied Physics, 47(8), p.6413 - 6415, 2008/08
A non-destructive and on-line diffusion tracing in Li ionic conductors has been demonstrated. As a tracer, pulsed beam of Li was implanted into LiGa. By analyzing the time dependent yield of the -particles decaying from Li, diffusion coefficients were extracted with a high accuracy. The ordering of Li vacancies in the Li-deficient phase of LiGa was observed for the first time in terms of the Li diffusion.
Yuki, Shunji*; Araki, Satoshi*; Suzuki, Takanori*; Osuga, Toshio*; Katayama, Koichi*; Hase, Yoshihiro; Yokota, Yuichiro
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 85, 2008/03
no abstracts in English
Sugai, Hiroyuki; Sataka, Masao; Okayasu, Satoru; Ichikawa, Shinichi; Nishio, Katsuhisa; Mitsuoka, Shinichi; Nakanoya, Takamitsu; Osa, Akihiko; Sato, Tetsuya; Hashimoto, Takashi; et al.
Defect and Diffusion Forum, 273-276, p.667 - 672, 2008/00
Ishiyama, Hironobu*; Hashimoto, Takashi; Ishikawa, Tomoko*; Watanabe, Yutaka*; Das, S. K.*; Miyatake, Hiroari; Mizoi, Yutaka*; Fukuda, Tomokazu*; Tanaka, Masahiko*; Fuchi, Yoshihide*; et al.
Physics Letters B, 640(3), p.82 - 85, 2006/09
The excitation function of the Li(,n)B reaction was measured while identifying the final state event by event in the region of E = 0.7 - 2.6 MeV using a highly efficient detector system and a low-energy Li beam. The results are much improved both in statistics and precisions, and show smaller cross sections than those of previous measurements by a factor of more than 2 in the low-energy region of E 1.5 MeV. A resonance-like structure is found at around E = 0.85 MeV.
Das, S. K.*; Fukuda, Tomokazu*; Mizoi, Yutaka*; Ishiyama, Hironobu*; Miyatake, Hiroari*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Tanaka, Masahiko*; Yoshikawa, Nobuharu*; Jeong, S.-C.*; et al.
AIP Conference Proceedings 847, p.374 - 376, 2006/07
no abstracts in English
Ishiyama, Hironobu*; Ishikawa, Tomoko*; Hashimoto, Takashi; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari; Tanaka, Masahiko*; Fuchi, Yoshihide*; Yoshikawa, Nobuharu*; et al.
Nuclear Instruments and Methods in Physics Research A, 560(2), p.366 - 372, 2006/05
Thanks to the nature of inverse transfer-reactions, low-energy radioactive nuclear beams in light neutron-rich region were produced. The mass-separation and velocity-separation of the JAERI recoil mass-separator help to form high purity beams. The beams of Li, B, and N-RNBs are utilized to the experiments, so far, with those beam intensities and purities of 1.410 pps and 99, 7.810 pps and 98, and 4.710 pps and 98.5, respectively.
Yamamoto, Sekika*; Ishibashi, Yasuhiko*; Inamura, Yasuhiro; Katayama, Yoshinori; Mishina, Tomobumi*; Nakahara, Junichiro*
Journal of Chemical Physics, 124(14), p.144511_1 - 144511_5, 2006/04
High pressure X-ray diffraction measurements on liquid carbon disulfide up to 1.2 GPa are performed by using an energy dispersion method. The results are compared with a molecular dynamics calculation with usual Lennard-Jones potential. They give very good agreement for all pressures measured. It becomes clear that the liquid structure changes like hard core liquid up to the pressure just below crystallizing point. The relation between structural change and optical response at high pressure is discussed.
Hashimoto, Takashi; Ishiyama, Hironobu*; Ishikawa, Tomoko*; Kawamura, Takashi*; Nakai, Koji*; Watanabe, Yutaka*; Miyatake, Hiroari; Tanaka, Masahiko*; Fuchi, Yoshihide*; Yoshikawa, Nobuharu*; et al.
Nuclear Instruments and Methods in Physics Research A, 556(1), p.339 - 349, 2006/01
A new type of three dimensional tracking and proportional gas counter has been developed. Adopting a gating-grid system, performance of the detector becomes stable under the injection rate of charged particles less than 410 pps. It is a useful detection system for astrophysical experiments using radioactive nuclear beams, since the efficiency is so high as 100 %.
Jeong, S.-C.*; Katayama, Ichiro*; Kawakami, Hirokane*; Watanabe, Yutaka*; Ishiyama, Hironobu*; Imai, Nobuaki*; Hirayama, Yoshikazu*; Miyatake, Hiroari; Sataka, Masao; Okayasu, Satoru; et al.
Journal of Phase Equilibria and Diffusion, 26(5), p.472 - 476, 2005/09
Authors developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound LiAl using an -emitting radiotracer of Li(T = 0.84 s). It was found that the time-dependent yields of the alpha particles from the diffusing 8Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in LiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects.
Jeong, S.-C.*; Katayama, Ichiro*; Kawakami, Hirokane*; Watanabe, Yutaka*; Ishiyama, Hironobu*; Miyatake, Hiroari*; Sataka, Masao; Okayasu, Satoru; Sugai, Hiroyuki; Ichikawa, Shinichi; et al.
Nuclear Instruments and Methods in Physics Research B, 230(1-4), p.596 - 600, 2005/04
no abstracts in English