Discrimination between active and non-active faults based on the chemical composition of fault gouge; An Attempt using linear discriminant analysis

Tateishi, Ryo*; Shimada, Koji; Shimizu, Mayuko; Ueki, Tadamasa*; Niwa, Masakazu; Sueoka, Shigeru; Ishimaru, Tsuneari

Oyo Chishitsu, 62(2), p.104 - 112, 2021/06

AA2020-0092.pdf:4.61MB

https://doi.org/10.5110/jjseg.62.104

We attempted to discriminate between active and non-active faults by linear discriminant analysis using the chemical composition data of fault gouges in Japan, and then examined the elements that represent the difference between them and better discriminants. As a result, the multiple discriminants obtained could discriminate between them with high probability. In addition, the generalization performance of these discriminants is discussed, and the discriminants that can be expected to have high discriminant performance for unknown samples are presented. Also, from the combination of elements common to these discriminants, we narrowed down the number of elements that represent the difference between active and non-active faults to 6, and showed that the combination of TiO and Sr contributing the most to the discrimination. The method applied in this study is an innovative one that can discriminate the activity by chemical analysis of fault rocks that are universally present in the bedrock.

Epitaxial thin film growth of europium dihydride

Komatsu, Yuya*; Shimizu, Ryota*; Wilde, M.*; Kobayashi, Shigeru*; Sasahara, Yuki*; Nishio, Kazunori*; Shigematsu, Kei*; Otomo, Akira*; Fukutani, Katsuyuki; Hitosugi, Taro*

Crystal Growth & Design, 20(9), p.5903 - 5907, 2020/09

https://doi.org/10.1021/acs.cgd.0c00602

Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal year 2018

Ishimaru, Tsuneari; Ogata, Nobuhisa; Hanamuro, Takahiro; Shimada, Akiomi; Kokubu, Yoko; Asamori, Koichi; Niwa, Masakazu; Shimada, Koji; Watanabe, Takahiro; Saiga, Atsushi; et al.

JAEA-Research 2019-006, 66 Pages, 2019/11

JAEA-Research-2019-006.pdf:4.39MB

This annual report documents the progress of research and development (R&D) in the 4th fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. In this report, the current status of R&D activities with previous scientific and technological progress is summarized.

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

https://doi.org/10.1038/s42005-019-0165-1

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific Program for fiscal year 2018)

Ishimaru, Tsuneari; Ogata, Nobuhisa; Shimada, Akiomi; Asamori, Koichi; Kokubu, Yoko; Niwa, Masakazu; Watanabe, Takahiro; Saiga, Atsushi; Sueoka, Shigeru; Komatsu, Tetsuya; et al.

JAEA-Review 2018-020, 46 Pages, 2019/01

JAEA-Review-2018-020.pdf:1.25MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency, in fiscal year 2018. The objectives and contents in fiscal year 2018 are described in detail based on the outline of 7 years plan (fiscal years 2015-2021). Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

CHIME monazite dating; Pb analysis on an R =100 mm spectrometer and correction of interferences between Th, U, and Pb with natural monazite

Shimizu, Mayuko; Shibata, Kenji*; Suzuki, Kazuhiro; Sueoka, Shigeru; Niwa, Masakazu

Journal of Mineralogical and Petrological Sciences, 112(2), p.88 - 96, 2017/04

https://doi.org/10.2465/jmps.160719d

This paper outlines an advanced procedure involving the chemical Th-U-total Pb isochron method (CHIME) dating of monazite using a field-emission electron probe microanalyzer (FE-EPMA) equipped with spectrometers of 100 mm Rowland circle (R) radius. The higher count rate of R = 100 mm wavelength dispersive spectrometer (WDS) compared to R = 140 mm WDS enables measurements to be taken in a shorter time. CHIME dating using R = 100 mm WDS had previously been difficult because of lower resolution compared to that of R = 140 mm WDS. This problem has been overcome by a new interference correction method using natural monazites.

Establishment of X-ray reference fields for performance tests of radiation measuring instruments based on international standard

Shimizu, Shigeru; Sawahata, Tadahiro*; Kajimoto, Yoichi; Shikaze, Yoshiaki; Yoshihara, Yasuaki*; Tatebe, Yosuke

JAEA-Technology 2011-008, 53 Pages, 2011/06

JAEA-Technology-2011-008.pdf:2.91MB

The International Standard, ISO 4037-1, is applied worldwide for setting the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. X-ray reference fields were established at the Facility of Radiation Standard in Nuclear Science Research Institute in 2003 and had been operated. Recently, we rebuilt the X-ray reference fields by replacing the X-ray tube with a new model due to the damage of the old one of the middle-hard X-ray irradiation device. We have established three series of medium-hard X-ray reference fields, Narrow, Wide and High air-kerma series with 27 radiation qualities, based on ISO 4037-1. This article described quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalent from Air-kerma and comparison with the quality of ISO 4037-1 in the X-ray fields of medium-hard X-ray voltages ranging from 20 kV to 300 kV. Result of experiments, these X-ray reference fields were well agreed with the condition of the international standard. As a result, these X-ray reference fields were found to be used to carry out the performance test, standard irradiation based on the international standard, and an intercomparison experiment with the reference laboratories in the world.

Establishment of soft X-ray reference fields for performance tests of radiation measuring instruments based on national standard

Shimizu, Shigeru; Fujii, Katsutoshi; Kawasaki, Tomokatsu

JAEA-Technology 2010-005, 72 Pages, 2010/06

JAEA-Technology-2010-005.pdf:2.44MB

In the Japanese Industrial Standard, JIS Z 4511 sets the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. With the soft X-ray generator installed in the Facility of Radiation Standard in Nuclear Science Research Institute, we have established four series of soft X-ray reference fields with quality index 0.6, 0.7, 0.8 and 0.9 based on JIS Z 4511. In this process, quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalent from Air-Kerma were evaluated in the soft X-ray fields produced with X-ray tube voltage ranging from 6 kV to 100 kV. As a result, it is found that dose equivalent standard with good precision and wide range of test energy point and dose rates can be provided, this report describes these detailed data.

Outline of the draft JIS on the calibration method of beta radiation dose equivalent meters

Shimizu, Shigeru

Hokeikyo Nyusu, (45), p.4 - 5, 2010/04

http://www.irm.or.jp/news45.pdf

In domestic JIS original bill making Committee, JIS original bill about the calibration method of the beta radiation dose equivalent meters were discussed newly, and it was reported to Japan Standards Association. Therefore I comment on the summary of this original bill and the future prospects including knowledge as the making committee.

Development of the neutron calibration fields using accelerators at FRS and TIARA of JAEA

Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Shimizu, Shigeru; Yoshizawa, Michio; Yamaguchi, Yasuhiro

Journal of Nuclear Science and Technology, 45(Suppl.5), p.209 - 212, 2008/06

https://doi.org/10.1080/00223131.2008.10875824

The neutron calibration fields is necessary to evaluate the energy response of the neutron monitors and dosimeters used in the facility such as J-PARC. The neutron calibration fields using accelerators, for the purpose, have been developed at the Facility of Radiation Standards (FRS) of JAEA-Tokai for neutrons below 20MeV and at Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) of JAEA-Takasaki for those over 20 MeV. At FRS, a 4 MV Van-de-Graaff (Pelletron) accelerator is used. Up until the present, developments of the 8, 144, 250, 565 keV, 5.0 and 14.8 MeV fields have been completed. At TIARA, an AVF cyclotron is used, and three neutron fields of 45, 60 and 75 MeV are planned to be established. For the development, evaluation of the characteristics of the field have been in process.