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Usui, Toshihide; Mikami, Satoshi; Hashimoto, Makoto; Nakayama, Naoto; Suzuki, Chihiro*; Tani, Kotaro*; Yamasaki, Keizo*; Misawa, Tsuyoshi*
KURRI Progress Report 2010, P. 209, 2011/10
no abstracts in English
Yokoyama, Sumi; Yamasaki, Keizo*; Oki, Yuichi*; Osada, Naoyuki*
Hoken Butsuri, 43(4), p.333 - 340, 2008/12
To assess internal exposure due to inhalation of radioactive aerosols and gases generated in high-energy accelerator facilities, physicochemical properties such as particle size of aerosols and chemical form of gases are important information. We measured the particle size distribution and concentration of aerosols coexisting with radionuclide formed by high-energy radiation emission in the target room of LINAC and estimated the long term variation of particle size and concentration of radioactive aerosols in high-energy acceleration facilities.
Rahman, N. M.*; Iida, Takao*; Saito, Fumihiro; Koarashi, Jun; Yamasaki, Keizo*; Yamazawa, Hiromi*; Moriizumi, Jun*
Radiation Protection Dosimetry, 123(2), p.171 - 181, 2007/02
Times Cited Count：12 Percentile：62.97(Environmental Sciences)no abstracts in English
Rn decay products in rainwater measured by 
-ray spectrometry using a low-background Ge detectorTakeyasu, Masanori; Iida, Takao*; Tsujimoto, Tadashi*; Yamasaki, Keizo*; Ogawa, Yoshihiro*
Journal of Environmental Radioactivity, 88(1), p.74 - 89, 2006/00
Times Cited Count：25 Percentile：48.51(Environmental Sciences)The concentrations of 
Pb and Bi in rainwater was measured by a low background Ge detector. The concentrations of Pb and Bi were inverse relations with rainfall rate in some rainfall events, and the concentration ratio of Bi to Pb would be a weak inverse relation with rainfall rate. The model was considered about the scavenging effects of rainfall to Radon decay products, and those results were discussed with the model.
Takeyasu, Masanori; Iida, Takao*; Tsujimoto, Tadashi*; Yamasaki, Keizo*
International Congress Series, 1276, p.289 - 290, 2004/00
The each concentration of Pb and Bi in rainwater was measured by a low background Ge detector. The concentration ofPb was a inverse relation with rainfall rate in some rainfall events, and the concentration ratio ofBi toPb was a weak inverse relation with rainfall rate in all rainfall events. These relations were the same as these obtained by the removal model of radon decay products from stratiform cloud.
Takeyasu, Masanori; Iida, Takao*; Tsujimoto, Tadashi*; Yamasaki, Keizo*
Proceedings of 6th International Conference on High Levels of Natural Radiation and Radon Areas, Program & Abstracts, (P-22), 85 Pages, 2004/00
The concentrations and its ratio of Pb-214 and Bi-214 in rainwater were measured by -ray spectrometry with a low background Ge detector, and the results were compared with the scavenging model of radon decay products from the atmosphere by precipitation. The each concentration of Pb-214 and Bi-214 in rainwater was constant and independent on precipitation rate for some precipitation events, and expressed with a power function of precipitation rate for the other events. The activity ratio of Bi-214 to Pb-214 was observed weak inverse correlated with precipitation rate. The measured ratio agreed fairly well with calculated one by the model.
Usui, Toshihide; Mikami, Satoshi; Nakayama, Naoto; Hashimoto, Makoto; Suzuki, Chihiro*; Yamasaki, Keizo*; Misawa, Tsuyoshi*
no journal, ,
no abstracts in English
Yamasaki, Keizo*; Oki, Yuichi*; Osada, Naoyuki*; Yokoyama, Sumi; Yamada, Yuji*; Tokonami, Shinji*; Fukutsu, Kumiko*; Iida, Takao*; Rahman, N. M.*; Shimo, Michikuni*
no journal, ,
no abstracts in English
Yamasaki, Keizo*; Oki, Yuichi*; Osada, Naoyuki*; Iida, Takao*; Shimo, Michikuni*; Yamada, Yuji*; Tokonami, Shinji*; Fukutsu, Kumiko*; Yokoyama, Sumi
no journal, ,
The physicochemical properties of radioactive aerosols are important factors to assess internal dose at high energy accelerator facilities. In Kyoto University Research Reactor Institute, a generation of radioactive aerosols in ADSR (Accelerator-Driven Subcritical Reactor) facilities was studied as part of the research project of ADSR. The generation of radioactive aerosols in high intensity irradiation fields of ADSR was simulated by irradiation of the target room air at LINAC. We measured the particle size of radioactive aerosols in the target room during the acceleration period. Natural radon aerosols in the target room grew to the larger size because of an attachment of radon daughters to non-radioactive aerosols. The particle size of the produced radioactive aerosols was also larger with time. This would mean that a formation mechanism of the radioactive aerosols produced at high energy accelerator facilities is the same as radon one.
Osada, Naoyuki*; Oki, Yuichi*; Yamasaki, Keizo*; Yokoyama, Sumi
no journal, ,
no abstracts in English
