Manufacture of substitutive assemblies for MONJU reactor decommissioning

Sakakibara, Hiroshi; Aoki, Nobuhiro; Muto, Masahiro; Otabe, Jun; Takahashi, Kenji*; Fujita, Naoyuki*; Hiyama, Kazuhiko*; Suzuki, Hirokazu*; Kamogawa, Toshiyuki*; Yokosuka, Toru*; et al.

JAEA-Technology 2020-020, 73 Pages, 2021/03

JAEA-Technology-2020-020.pdf:8.26MB

The decommissioning is currently in progress at the prototype fast breeder reactor Monju. Fuel assemblies will be taken out of its core for the first step of the great task. Fuel assemblies stand on their own spike plugged into a socket on the core support plate and support with adjacent assemblies through their housing pads each other, resulting in steady core structure. For this reason, some substitutive assemblies are necessary for the purpose of discharging the fuel assemblies of the core. Monju side commissioned, therefore, Plutonium Fuel Development Center to manufacture the substitutive assemblies and the Center accepted it. This report gives descriptions of design, manufacture, and shipment in regard to the substitutive assemblies.

Temperature of thermal spikes induced by swift heavy ions

Matsuzaki, Shota*; Hayashi, Hiroaki*; Nakajima, Kaoru*; Matsuda, Makoto; Sataka, Masao*; Tsujimoto, Masahiko*; Toulemonde, M.*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 406(Part B), p.456 - 459, 2017/09

https://doi.org/10.1016/j.nimb.2016.12.019

Temperature of thermal spikes in amorphous silicon nitride films produced by 1.11 MeV C impacts

Kitayama, Takumi*; Nakajima, Kaoru*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Matsuda, Makoto; Sataka, Masao*; Tsujimoto, Masahiko*; Isoda, Shoji*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 354, p.183 - 186, 2015/07

https://doi.org/10.1016/j.nimb.2014.11.002

Sputtering of SiN films by 540 keV C ions observed using high-resolution Rutherford backscattering spectroscopy

Nakajima, Kaoru*; Morita, Yosuke*; Kitayama, Takumi*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Tsujimoto, Masahiko*; Isoda, Shoji*; Fujii, Yoshikazu*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 332, p.117 - 121, 2014/08

https://doi.org/10.1016/j.nimb.2014.02.042

Direct observation of fine structure in ion tracks in amorphous SiN by TEM

Nakajima, Kaoru*; Morita, Yosuke*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Ishikawa, Norito; Hojo, Kiichi; Tsujimoto, Masahiko*; Isoda, Shoji*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 291, p.12 - 16, 2012/11

https://doi.org/10.1016/j.nimb.2012.09.007

Thin films of amorphous SiN (thickness 20 nm) were irradiated with 120-720 keV C ions and observed using transmission electron microscopy (TEM). The ion track produced in an amorphous material was directly observed by TEM. For quantitative analysis, the ion tracks were also observed using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The observed ion track consists of a low density core (radius 2.5 nm) and a high density shell (width 2.5 nm), which is very similar to the ion tracks in amorphous SiO irradiated with high energy heavy ions observed by small angle X-ray scattering (SAXS). Although the observed ion tracks may be affected by surface effects, the present result indicates that TEM and HAADF-STEM have potential to observe directly the fine structures of ion tracks in amorphous materials.

Superdeformation in asymmetric nucleus Ar

Ideguchi, Eiji*; Ota, Shinsuke*; Morikawa, Tsuneyasu*; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Nakamura, Shoji; et al.

Physics Letters B, 686(1), p.18 - 22, 2010/03

https://doi.org/10.1016/j.physletb.2010.02.031

A rotational band with five -ray transitions ranging from 2 to 12 states was identified in Ar. The deduced transition quadrupole moment of 1.45 0.15 eb indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartee Fock Bogoliubov calculations and a multiparticle-multihole configuration is assigned to the band.

Determination of arsenic and antimony in "Tatara" steel making sample by neutron activation analysis combined with multiple -ray detection

Inoshita, Shinya*; Suzuki, Shogo*; Okada, Yukiko*; Kato, Masahiko*; Hirai, Shoji*; Kimura, Atsushi; Hatsukawa, Yuichi; Toh, Yosuke; Koizumi, Mitsuo; Oshima, Masumi

Tetsu To Hagane, 94(9), p.345 - 350, 2008/09

https://doi.org/10.2355/tetsutohagane.94.345

"Tatara" is Japanese original steel making method. Steel made by "Tatara" is famous as low alloy and suited to "Kaji" process. By authors' study, it turned out that we could estimate the source region of raw material of Tatara by As and Sb concentration ratio in Tatara sample. But the concentration of these element in Tatara sample is very low (ppm or sub-ppm order), therefore, quantitative analysis is very difficult. In this study, we adopted Neutron Activation Analysis combined with Multiple -ray detection (NAAMG) to analyze As and Sb in "Tatara" sample (iron lump and sand iron, slag). NAAMG is high sensitive and non-destructive analysis method which combined NAA (Neutron Activation Analysis) and multiple -ray detectors. Each "Tatara" sample (iron lump, sand iron, slag) were irradiated for 1-2 h (for As measurement), 8-17 h (for Sb measurement) in JRR-3M HR irradiation field (thermal neutron flux was about 9.010 n/m s). And cooling time was 4-5 days (As), and 19-36 days (Sb). Coincidence -rays were measured by -ray detector array, GEMINI-II. Counting time was 1-8 hours (As), and 2-41 hours (Sb). Quantification was made by comparison method. As a result of measurement, the concentration of As and Sb in all "Tatara" samples were determined by NAAMG and these were sub-ppm order. Lower Limit of Determination (LLD) of As was 0.1 ppm order and Sb is 0.01ppm order. From the above-mentioned point, the effectiveness of NAAMG to analyze trace element in "Tatara" sample was confirmed.

Search for signature inversion in the bands in 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

https://doi.org/10.1142/S0218301306005125

Search for low-spin signature inversion in the bands in odd-odd Au have been made through in-beam -ray spectroscopy techniques. The bands in the three nuclei have been identified and extended up to high-spin states. In particlular, the interband connection between the band and the ground-state band in Au have been established, leading to a firm spin-and-parity assignment for the band. The low-spin signature inversion is found in the bands in Au.

Status of J-PARC muon science facility at the year of 2005

Miyake, Yasuhiro*; Nishiyama, Kusuo*; Kawamura, Naritoshi*; Makimura, Shunsuke*; Strasser, P.*; Shimomura, Koichiro*; Beveridge, J. L.*; Kadono, Ryosuke*; Fukuchi, Koichi*; Sato, Nobuhiko*; et al.

Physica B; Condensed Matter, 374-375, p.484 - 487, 2006/03

https://doi.org/10.1016/j.physb.2005.11.136

The construction of the Materials and Life Science building was started in the beginning of the fiscal year of 2004. After commissioning of the accelerator and beam transport sections in 2008, muon beams will be available for users in 2009. In this letter, the latest construction status of the J-PARC Muon Science Facility is reported.

J-PARC muon science facility with use of 3GeV proton beam

Miyake, Yasuhiro*; Kawamura, Naritoshi*; Makimura, Shunsuke*; Strasser, P.*; Shimomura, Koichiro*; Nishiyama, Kusuo*; Beveridge, J. L.*; Kadono, Ryosuke*; Sato, Nobuhiko*; Fukuchi, Koichi*; et al.

Nuclear Physics B; Proceedings Supplements, 149, p.393 - 395, 2005/12

The J-PARC muon science experimental area is planned to be located in the integrated building of the facility for materials and life science study. One muon target will be installed upstream of the neutron target. The main feature of the facility is introduced.