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Journal Articles

Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

Sonoda, Tetsu*; Katayama, Ichiro*; Wada, Michiharu*; Iimura, Hideki; Sonnenschein, V.*; Iimura, Shun*; Takamine, Aiko*; Rosenbusch, M.*; Kojima, Takao*; Ahn, D. S.*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(11), p.113D02_1 - 113D02_12, 2019/11

 Times Cited Count:0 Percentile:100(Physics, Multidisciplinary)

An in-flight separator, BigRIPS, at RIBF in RIKEN provides each experiment with specific nuclides separated from many nuclides produced by projectile fragmentation or in-flight fission. In this process, nuclides other than separated ones are discarded on the slits in BigRIPS, although they include many nuclides interested from the view point of nuclear structure. In order to extract these nuclides for parasitic experiments, we are developing a method using laser ion-source (PALIS). A test experiment with $$^{78}$$Se beam from RIBF has been performed by using a gas cell set in BigRIPS. Unstable nuclides around $$^{67}$$Se were stopped in the gas cell in accordance with a calculation using LISE code. The stopping efficiency has been estimated to be about 30%. As a next step, we will establish the technique for extracting reaction products from the gas cell.

Journal Articles

The Laser and optical system for the RIBF-PALIS experiment

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

 Times Cited Count:3 Percentile:40.19(Instruments & Instrumentation)

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%.

Journal Articles

Nanoscale diffusion tracing by radioactive $$^{8}$$Li tracer

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

 Times Cited Count:4 Percentile:82.21(Physics, Applied)

Journal Articles

Mechanical properties of full austenitic welding joint at cryogenic temperature for the ITER toroidal field coil structure

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

 Times Cited Count:8 Percentile:37.16(Nuclear Science & Technology)

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.

Journal Articles

Tilted-foil technique for producing a spin-polarized radioactive isotope beam

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

 Times Cited Count:2 Percentile:80.67(Physics, Nuclear)

Journal Articles

Low-background prebunching system for heavy-ion beams at the Tokai radioactive ion accelerator complex

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

 Times Cited Count:1 Percentile:88.95(Physics, Nuclear)

Journal Articles

Development in fabrication structures for the ITER toroidal field coils

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.

Journal Articles

Precise structural analyses of advanced materials under high-pressure and high-temperature

Yoshiasa, Akira*; Murai, Keiichiro*; Arima, Hiroshi*; Katayama, Yoshinori

International Journal of Modern Physics B, 25(31), p.4159 - 4162, 2011/12

 Times Cited Count:0 Percentile:100(Physics, Applied)

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.

Journal Articles

Systematic analysis method for radioactive wastes generated from nuclear research facilities

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 $$gamma$$-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.

JAEA Reports

Simple and rapid determination methods for low-level radioactive wastes generated from nuclear research facilities (Guidelines for determination of radioactive waste samples)

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 $$gamma$$-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.

Journal Articles

Anomalous metallic state in the vicinity of metal to valence-bond solid insulator transition in LiVS$$_{2}$$

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

 Times Cited Count:41 Percentile:14.01(Physics, Multidisciplinary)

We investigate LiVS$$_{2}$$ and LiVSe$$_{2}$$ with a triangular lattice as itinerant analogues of LiVO$$_{2}$$ known for the formation of a valence-bond solid (VBS) state out of an S = 1 frustrated magnet. LiVS$$_{2}$$, 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$$_{c}$$ $$sim$$ 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$$_{2}$$ has a pseudogap, likely originating from the VBS fluctuation. LiVSe$$_{2}$$ was found to be a paramagnetic metal down to 2 K.

Journal Articles

On-line diffusion tracing in Li ionic conductors by the short-lived radioactive beam of $$^{8}$$Li

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

 Times Cited Count:5 Percentile:75.06(Physics, Applied)

A non-destructive and on-line diffusion tracing in Li ionic conductors has been demonstrated. As a tracer, pulsed beam of $$^{8}$$Li was implanted into LiGa. By analyzing the time dependent yield of the $$alpha$$-particles decaying from $$^{8}$$Li, diffusion coefficients were extracted with a high accuracy. The ordering of Li vacancies in the Li-deficient $$beta$$ phase of LiGa was observed for the first time in terms of the Li diffusion.

Journal Articles

Breeding new varieties of miniature ${it Cymbidium}$ using ion beam irradiation

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

Journal Articles

Diffusion of $$^{8}$$Li short-lived radiotracer in Li ionic conductors of NaTl-type intermetallic compounds

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

Journal Articles

A New measurement of the astrophysical $$^8$$Li($$alpha$$, n)$$^{11}$$B reaction

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

 Times Cited Count:31 Percentile:13.94(Astronomy & Astrophysics)

The excitation function of the $$^{8}$$Li($$alpha$$,n)$$^{11}$$B reaction was measured while identifying the final state event by event in the region of E$$_{rm{cm}}$$ = 0.7 - 2.6 MeV using a highly efficient detector system and a low-energy $$^8$$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$$_{rm{cm}}le$$ 1.5 MeV. A resonance-like structure is found at around E$$_{rm{cm}}$$ = 0.85 MeV.

Journal Articles

A New measurement of the $$^8$$Li($$alpha$$,n)$$^{11}$$B reaction for astrophysical interest

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

Journal Articles

Production of a low-energy radioactive nuclear beam with high purity using JAERI-RMS

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

 Times Cited Count:7 Percentile:50.48(Instruments & Instrumentation)

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 $$^8$$Li, $$^{12}$$B, and $$^{16}$$N-RNBs are utilized to the experiments, so far, with those beam intensities and purities of 1.4$$times$$10$$^4$$ pps and 99$$%$$, 7.8$$times$$10$$^3$$ pps and 98$$%$$, and 4.7$$times$$10$$^3$$ pps and 98.5$$%$$, respectively.

Journal Articles

Pressure dependence of local structure in liquid carbon disulfide

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

 Times Cited Count:10 Percentile:64.67(Chemistry, Physical)

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.

Journal Articles

Gated multiple-sampling and tracking proportional chamber; New detector system for nuclear astrophysical study with radioactive nuclear beams

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

 Times Cited Count:30 Percentile:9.96(Instruments & Instrumentation)

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 4$$times$$10$$^4$$ pps. It is a useful detection system for astrophysical experiments using radioactive nuclear beams, since the efficiency is so high as 100 %.

Journal Articles

Measurement of self-diffusion coefficients in Li ionic conductors by using the short-lived radiotracer of $$^8$$Li

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 $$beta$$LiAl using an $$alpha$$-emitting radiotracer of $$^8$$Li(T$$_{1/2}$$ = 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 $$beta$$LiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects.

47 (Records 1-20 displayed on this page)