著者
Satoshi MIKAMI Shoji SATO Yoshifumi HOSHIDE Ryuichi SAKAMOTO Naotoshi OKUDA Kimiaki SAITO
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.50, no.3, pp.182-188, 2015 (Released:2016-02-06)
参考文献数
12
被引用文献数
13

Intercomparison of in situ gamma spectrometry was organized at a site contaminated by the radioactive fallout that originated from the Fukushima Dai-ichi Nuclear Power Plant accident. This intercomparison was conducted by eight teams from four different institutions, which have contributed to the government-led project to construct distribution maps of radionuclides deposited on the ground soil. The resultant 134Cs and 137Cs inventories evaluated by the participants agreed within 6% of the coefficient of variation, after correction for inhomogeneous distribution of the dose rate in air. The evaluated 40K inventories agreed within 4% of the coefficient of variation. The authors estimated that these results were in good agreement for creating distribution maps of the radionuclide inventory in the ground soil.
著者
Akinobu MATSUYAMA Ryuichi SAKAMOTO
出版者
The Japan Society of Plasma Science and Nuclear Fusion Research
雑誌
Plasma and Fusion Research (ISSN:18806821)
巻号頁・発行日
vol.17, pp.2402017, 2022-03-30 (Released:2022-04-23)
参考文献数
10
被引用文献数
1

Cryogenic neon pellets of 3 mm in diameter were injected into neutral beam injection (NBI) heated discharges on the Large Helical Device (LHD). The time response of far infrared (FIR) interferometer has pointed out a relatively slow assimilation of the ablated materials compared to the cases of hydrogen injection. This is consistent with the neutral gas and plasma shielding (NGPS) model prediction, showing that strong line emission inside the ablation cloud limits the cloud temperature and the expansion velocity along the magnetic field line. Measured penetration depths were also compared, being well reproduced by the code prediction when the contribution from 180 keV fast ions produced by tangential NBI is taken into account.
著者
Ryuichi SAKAMOTO Suguru MASUZAKI Junichi MIYAZAWA LHD Experimental Group
出版者
The Japan Society of Plasma Science and Nuclear Fusion Research
雑誌
Plasma and Fusion Research (ISSN:18806821)
巻号頁・発行日
vol.1, pp.019, 2006 (Released:2006-07-27)
参考文献数
4
被引用文献数
4 6

A high-luminosity striation, which rotates within a flux surface of the plasma boundary having helical structure, has been observed in the LHD plasmas by means of a fast camera. The striation appears when the plasma is shrinking due to excessive gas fueling despite the existence of neutral beam heating.