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Journal Articles

Rapid multi-nuclide identification method by simultaneous $$beta$$, $$gamma$$, and X-ray spectrum analysis

Oshima, Masumi*; Goto, Jun*; Hayakawa, Takehito*; Asai, Masato; Kin, Tadahiro*; Shinohara, Hirofumi*

Isotope News, (790), p.19 - 23, 2023/12

When analyzing samples that contain many radionuclides at various concentrations, such as radioactive waste or fuel debris, it is difficult to apply general spectrum analysis methods and is necessary to chemically separate each nuclide before quantifying it. The chemical separation is especially essential for analysis using a liquid scintillation counter (LSC). In this report, the authors explain the newly developed spectral determination method (SDM) in which the entire spectrum is fitted to quantify radioactivity of nuclides mixed in a sample. By applying the SDM to $$beta$$- and X-ray spectrum measured by LSC and $$gamma$$-ray spectrum measured by Ge detector simultaneously, the authors demonstrated that radioactivity of 40 radionuclides mixed in a sample at concentrations varying by two orders could be quantified, which is useful to simplify chemical separation process in radionuclide quantification.

Journal Articles

High-rate performance of a time projection chamber for an H-dibaryon search experiment at J-PARC

Kim, S. H.*; Ichikawa, Yudai; Sako, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei*; Nanamura, Takuya*; Sato, Susumu; Tanida, Kiyoshi; Yoshida, Junya; 11 of others*

Nuclear Instruments and Methods in Physics Research A, 940, p.359 - 370, 2019/10

 Times Cited Count:5 Percentile:49.54(Instruments & Instrumentation)

Journal Articles

Observation of a Be double-Lambda hypernucleus in the J-PARC E07 experiment

Ekawa, Hiroyuki; Ashikaga, Sakiko; Hasegawa, Shoichi; Hashimoto, Tadashi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji*; Nanamura, Takuya; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.021D02_1 - 021D02_11, 2019/02

 Times Cited Count:23 Percentile:84.13(Physics, Multidisciplinary)

Journal Articles

Charge identification of low-energy particles for double-strangeness nuclei in nuclear emulsion

Kimbara, Shinji*; Ekawa, Hiroyuki; Hayakawa, Shuhei; Yoshida, Junya; 12 of others*

Progress of Theoretical and Experimental Physics (Internet), 2019(1), p.011H01_1 - 011H01_9, 2019/01

 Times Cited Count:3 Percentile:37.12(Physics, Multidisciplinary)

A development has been achieved in the identification method of the charges 1 to 5 of nuclides from the decay of double hypernuclei to be uniquely recognized by their nuclear species. The method is basically the measurement of track volume by the widths, depths, and angles of tracks of exposed nuclei of $$^{1}$$H, $$^{4}$$He, $$^{7}$$Li, $$^{9}$$Be, and $$^{11}$$B in nuclear emulsion at Riken Projectile-fragment Separator of RIKEN Radioactive Isotope Beam Factory. After their calibration by $$alpha$$ particles, we obtained a quadric function to present a unified recognition of tracks with volume ratios of five nuclei to the $$alpha$$ particles. The function in the emulsion has been applied to a candidate event of a $$Xi$$ hypernucleus for identification of the production and decay processes. We succeeded in recognizing a daughter nuclear fragment of a single-$$Lambda$$ hypernucleus as $$^{6}$$He with a likelihood ratio of 0.9; the process was then uniquely identified as $$Xi$$$$^{-}$$ + $$^{14}$$N $$rightarrow$$ $$_{Lambda}$$$$^{9}$$Be + $$_{Lambda}$$$$^{5}$$He + $$n$$.

Journal Articles

Welding technology on sector assembly of the JT-60SA vacuum vessel

Shibama, Yusuke; Okano, Fuminori; Yagyu, Junichi; Kaminaga, Atsushi; Miyo, Yasuhiko; Hayakawa, Atsuro*; Sagawa, Keiich*; Mochida, Tsutomu*; Morimoto, Tamotsu*; Hamada, Takashi*; et al.

Fusion Engineering and Design, 98-99, p.1614 - 1619, 2015/10

 Times Cited Count:4 Percentile:33.51(Nuclear Science & Technology)

The JT-60SA vacuum vessel (150 tons) is a double wall torus structure and the maximum major radius of 5.0 m and height of 6.6 m. The manufacturing design concept is that the vessel is split in the 10 toroidal sectors manufactured at factory, and assembled on-site; seven of the 40-degree sectors, two of the 30-degree beside final one, and the final of the 20-degree. The final sector is assembled with the VV thermal shield and toroidal field magnets into the 340-degree as prepared in one sector. Sectors are temporally fitted on-site and adjusted one over the other before the assembly. After measurement of the dimensions and the reference, these sectors are transferred onto the cryostat base. First, three 80-degree sectors are manufactured with mating each 40-degree sector by direct joint welding. The rest sectors including the final sector are jointed with splice plates. Welding manipulator and its guide rails are used for these welding. In this paper, the detail of the VV sectors assembly including the final sector is explained. Welding technologies to joint the two of 40-degree sectors are reported with the present manufacturing status and the welding trial on the vertical stub with the partial mock-up of the final sector are discussed with the assembly process.

Journal Articles

Assembly study for JT-60SA tokamak

Shibanuma, Kiyoshi; Arai, Takashi; Hasegawa, Koichi; Hoshi, Ryo; Kamiya, Koji; Kawashima, Hisato; Kubo, Hirotaka; Masaki, Kei; Saeki, Hisashi; Sakurai, Shinji; et al.

Fusion Engineering and Design, 88(6-8), p.705 - 710, 2013/10

 Times Cited Count:10 Percentile:61.35(Nuclear Science & Technology)

Journal Articles

Development of basic NDA technologies of nuclear material accountancy of debris of melted fuel formed in severe accidents

Seya, Michio; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Iimura, Hideki; Kureta, Masatoshi; Takamine, Jun; Hajima, Ryoichi; Hayakawa, Takehito; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 10 Pages, 2013/10

The forming of MF in severe accidents of nuclear reactors such as Units 1 - 3 of Fukushima-Daiichi NPP (Nuclear Power Plant) inevitably change the category of the nuclear reactor from "item facility" to "bulk-handling facility". At removal of the MF it is necessary to break chunks of MF into relatively small blocks by using some tools, resulting in debris that consists of cut or small rock-like debris and particle (or grain)-like debris in bulk form. This paper presents a categorization of debris of MF and two possible non-destructive assay (NDA) technologies for precise measurement which could be applied to the NM accountancy of MF debris. One of them is Neutron Resonance Densitometry (NRD) for particle-like (or grain-like) debris, and another is NRF (Nuclear Resonance Fluorescence) NDA using LCS (Laser Compton Scattered) $$gamma$$-rays (mono-energetic $$gamma$$-rays) for cut or small rock-like debris. The paper also describes about the recent development of these two technologies.

Journal Articles

Development of basic NDA technologies for nuclear material accountancy of debris of melted fuel formed in severe accidents

Seya, Michio; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Iimura, Hideki; Kureta, Masatoshi; Takamine, Jun; Hajima, Ryoichi; Hayakawa, Takehito; et al.

Proceedings of INMM 54th Annual Meeting (CD-ROM), 9 Pages, 2013/07

The forming of MF in a severe accident of a nuclear reactor may change the category of the nuclear reactor from item facility to non-item facility. Taking this removal process into account, the damaged reactor could be categorized as a bulk-handling facility. The NM accountancy is essential for the safeguards of a bulk-handling facility. This paper presents a categorization of debris of MF (into cut or small rock-like debris and particle (or grain)-like debris) and a selection of possible NDA technologies which could be applied to the NM accountancy of MF debris. The paper introduces two NDA technologies for NM accountancy of debris: NRD for particle-like (or grain-like) debris, and NRF NDA using LCS $$gamma$$ rays for cut or small rock-like debris. The paper also describes about the development of basic parts of these two technologies and near future plan.

Journal Articles

Feasibility studies and development of NDA technologies for nuclear materials in the melted fuels formed in severe accidents

Seya, Michio; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Iimura, Hideki; Kureta, Masatoshi; Takamine, Jun; Hajima, Ryoichi; Hayakawa, Takehito; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-33-Kai Nenji Taikai Rombunshu (Internet), 10 Pages, 2012/10

This paper presents feasibility (selection) study of NDA techniques, NRD (Neutron Resonance Densitometry) and LCSG-NRF (LCS $$gamma$$-rays interrogation Nuclear Resonance Fluorescence), to measure nuclear material (NM) in debris of melted fuel with high precision. The melted fuel under consideration here is the one formed by the severe loss of coolant accidents of such as Units 1 - 3 of Fukushima-Daiichi NPP. NRD based on NRTA (Neutron Resonance Transmission Analysis) and NRCA (Neutron Resonance Capture Analysis) utilizing the TOF (Time of Flight) method is intended for measurement of NM (all isotopes of U/Pu) in particle-like debris. LCSG-NRF using intense LCS (Laser Compton Scattered) $$gamma$$-rays (mono-energetic $$gamma$$-rays) is to measure NM (all isotopes of U/Pu) in small rock-like debris and cut-shape debris (cylindrical, slab-shpape). In this paper we also summarize advantages of two techniques compared with other NDA techniques.

Journal Articles

Spectroscopic study of $$^{63}$$Ni via cold neutron capture reaction, 1; Nuclear structure of $$^{63}$$Ni

Oshima, Masumi; Kin, Tadahiro*; Nakamura, Shoji; Homma, Michio*; Minato, Futoshi; Hayakawa, Takehito; Hara, Kaoru; Kimura, Atsushi; Koizumi, Mitsuo; Harada, Hideo; et al.

Journal of the Physical Society of Japan, 81(8), p.084201_1 - 084201_15, 2012/08

 Times Cited Count:2 Percentile:19.32(Physics, Multidisciplinary)

The $$gamma$$-radiation has been investigated produced by cold neutron capture in an enriched $$^{62}$$Ni sample. The 315 $$gamma$$-rays have been placed in the $$^{63}$$Ni level scheme of which 272 placements are new. We have determined excitation energies with 0.2-0.8 keV error and branching ratios of 62 bound levels in $$^{63}$$Ni, including 30 new levels. The Q-value of the $$^{62}$$Ni (n,$$gamma$$) $$^{63}$$Ni reaction amounts to 6837.75 (18) keV. A large-scale shell-model calculation has been performed and the energies of the low-lying $$^{63}$$Ni states are successfully reproduced. A mean-field statistical model calculation has been also made by using a self-consistent interaction between the Hartree-Fock + BCS method and the statistical calculation. The calculation result is consistent with the experimental level density of $$^{63}$$Ni.

Journal Articles

Reduction of intrinsic critical current density under a magnetic field along the hard axis of a free layer in a magnetic tunnel junction

Miura, Katsuya*; Sugano, Ryoko*; Ichimura, Masahiko*; Hayakawa, Jun*; Ikeda, Shoji*; Ohno, Hideo*; Maekawa, Sadamichi

Physical Review B, 84(17), p.174434_1 - 174434_7, 2011/11

 Times Cited Count:1 Percentile:5.41(Materials Science, Multidisciplinary)

Journal Articles

Multiferroic character and magnetic phase of LuFe$$_{2}$$O$$_{4}$$

Oishi, Daisuke*; Hayakawa, Hironori*; Akahama, Hiroshi*; Ikeda, Naoshi*; Kambe, Takashi*; Matsuo, Yoji*; Kimizuka, Noboru*; Kano, Jun*; Yoshii, Kenji

Ferroelectrics, 415(1), p.51 - 56, 2011/10

 Times Cited Count:5 Percentile:25.44(Materials Science, Multidisciplinary)

The variation of AC dielectric constant in the function of the DC magnetic fields was found in low oxygen vacant LuFe$$_{2}$$O$$_{4}$$ single crystal in which the electric polarization arise from the polar charge ordering. These magneto-electric coupling should be explained by a novel mechanism where the boundary motion of the polar charge ordered domain is affected by the magnetic (spin) domain boundary motion.

Journal Articles

The H-Invitational Database (H-InvDB); A Comprehensive annotation resource for human genes and transcripts

Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.

Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01

 Times Cited Count:51 Percentile:71.37(Biochemistry & Molecular Biology)

Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.

Journal Articles

Safeguards improvement for the Tokai Reprocessing Plant (TRP)

Onizawa, Toshikazu; Kimura, Takashi; Kurosu, Kazutoshi; Hayakawa, Tsuyoshi; Fukuhara, Junichi; Yatsu, Shoichi*

STI/PUB/1298 (CD-ROM), p.739 - 745, 2007/08

no abstracts in English

Journal Articles

Search for signature inversion in the $$pi i_{13/2} bigotimes nu i_{13/2}$$ bands in $$^{182,184,186}$$Au

Zhang, Y. H.*; Zhou, X. H.*; He, J. J.*; Liu, Z.*; Fang, Y. D.*; Guo, W. T.*; Lei, X. G.*; Guo, Y. X.*; Ndontchueng, M. M.*; Ma, L.*; et al.

International Journal of Modern Physics E, 15(7), p.1437 - 1445, 2006/10

 Times Cited Count:3 Percentile:28.2(Physics, Nuclear)

Search for low-spin signature inversion in the $$pi i_{13/2} bigotimes nu i_{13/2}$$ bands in odd-odd $$^{182,184,186}$$Au have been made through in-beam $$gamma$$-ray spectroscopy techniques. The $$pi i_{13/2} bigotimes nu i_{13/2}$$ bands in the three nuclei have been identified and extended up to high-spin states. In particlular, the interband connection between the $$pi i_{13/2} bigotimes nu i_{13/2}$$ band and the ground-state band in $$^{184}$$Au have been established, leading to a firm spin-and-parity assignment for the $$pi i_{13/2} bigotimes nu i_{13/2}$$ band. The low-spin signature inversion is found in the $$pi i_{13/2} bigotimes nu i_{13/2}$$ bands in $$^{182,184,186}$$Au.

Journal Articles

Coulomb excitation experiments at JAEA Tandem facility for the study of nuclear structure

Koizumi, Mitsuo; Toh, Yosuke; Osa, Akihiko; Kimura, Atsushi; Utsuno, Yutaka; Oshima, Masumi; Hayakawa, Takehito; Hatsukawa, Yuichi; Katakura, Junichi; Matsuda, Makoto; et al.

Proceedings of the International Workshop on Quark Nuclear Physics 2006, p.245 - 252, 2006/00

no abstracts in English

Journal Articles

Multi-quasiparticle excitations in $$^{145}$$Tb

Zheng, Y.*; Zhou, X. H.*; Zhang, Y. H.*; Hayakawa, Takehito; Oshima, Masumi; Toh, Yosuke; Shizuma, Toshiyuki; Katakura, Junichi; Hatsukawa, Yuichi; Matsuda, Makoto; et al.

Journal of Physics G; Nuclear and Particle Physics, 30(4), p.465 - 479, 2004/04

 Times Cited Count:8 Percentile:48.09(Physics, Nuclear)

no abstracts in English

Journal Articles

Multiple coulomb excitation experiment of $$^{68}$$Zn

Koizumi, Mitsuo; Seki, Akiyuki*; Toh, Yosuke; Osa, Akihiko; Utsuno, Yutaka; Kimura, Atsushi; Oshima, Masumi; Hayakawa, Takehito; Hatsukawa, Yuichi; Katakura, Junichi; et al.

Nuclear Physics A, 730(1-2), p.46 - 58, 2004/01

 Times Cited Count:17 Percentile:72.57(Physics, Nuclear)

Coulomb excitation experiment was carried out with a $$^{68}$$Zn beam bombarding a $$^{nat}$$Pb target. Two $$E2$$ matrix elements and the quadrupole moment of the 2$$_{1}$$$$^{+}$$ state were newly derived with the least-squares search code GOSIA. The potential energy surface (PES) was calculated with the Nilsson-Strutinsky model, showing two shallow minima: the first minimum does not contain the $$1g_{9/2}$$ orbit below the Fermi surface, while the second minimum does. The ground state band and the intruder band seem to be constructed on the first and the second minimum, respectively. As for the ground state band, the asymmetric rotor model and the IBM in O(6) limit reproduced the experimental values rather well. The shallow PES may suggest unstability of the shape. The ground state band structure may be explained assuming a soft triaxial deformation.

Journal Articles

High spin states in $$^{158}$$Dy

Hayakawa, Takehito; Toh, Yosuke; Oshima, Masumi; Matsuda, Makoto; Hatsukawa, Yuichi; Shizuma, Toshiyuki; Katakura, Junichi; Iimura, Hideki; Mitarai, Shiro*; Zhang, Y.*; et al.

Physical Review C, 68(6), p.067303_1 - 067303_4, 2003/12

 Times Cited Count:2 Percentile:21.3(Physics, Nuclear)

no abstracts in English

Journal Articles

Multiple Coulomb Excitation Experiment of $$^{66}$$Zn

Koizumi, Mitsuo; Seki, Akiyuki*; Toh, Yosuke; Oshima, Masumi; Osa, Akihiko; Kimura, Atsushi; Hatsukawa, Yuichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Matsuda, Makoto; et al.

European Physical Journal A, 18(1), p.87 - 92, 2003/10

 Times Cited Count:14 Percentile:68.48(Physics, Nuclear)

no abstracts in English

43 (Records 1-20 displayed on this page)