Basic study for on-line monitoring of tiny particles including alpha emitters by aerosol time-of-flight mass spectroscopy (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*

JAEA-Review 2021-074, 104 Pages, 2022/03

JAEA-Review-2021-074.pdf:4.91MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Basic study for on-line monitoring of tiny particles including alpha emitters by aerosol time-of-flight mass spectroscopy" conducted in FY2019 and FY2020. Since the final year of this proposal was FY2020, the results for two fiscal years were summarized. The present study aims to conduct a feasibility study of Aerosol time-of-flight mass spectroscopy (ATOFMS) to on-line measurement of tiny particles containing alpha emitters which might be dispersed in cutting the debris in reactors of the Fukushima Daiichi Nuclear Power Station for realizing their real-time monitoring.

Determination of coating contamination in coated particles

; Iwamoto, K.

Journal of Nuclear Science and Technology, 13(3), p.132 - 138, 1976/03

https://doi.org/10.3327/jnst.13.132

no abstracts in English

Light yield maximization of triclinic La-GPS scintillator by optimizing La and Ce concentration

Tsubota, Yoichi; Waki, Takaaki*; Kaneko, Junichi*; Higuchi, Mikio*; Ishibashi, Hiroyuki*

no journal, , 

GdSiO:Ce (GPS) is a rare-earth oxide scintillator with large light yield (LY) exceed NaI:Tl and can be used under high temp. environment. The triclinic La-GPS, which substituted Gd site for La, also have LY close to NaI:Tl. Although several trials on growth of La-GPS were reported, systematic research on LY were not sufficiently carried out. In this report, the optimization of La and Ce concentration of La-GPS was conducted to maximize LY. Sintered (LaxGd1-x-yCey)SiO (x= 0.1, y= 0 - 0.16) and (x= 0 - 0.15, y= 0.025) were fixed on glass plates and mechanically polished to be approx. 100 micro-meter thick. For the evaluation of scintillation LY, alpha-particle response measurement using Am was performed. For the Ce= 2.5% samples, La-GPS with 5 - 6.7% of La showed the highest LY. LY was then decreased as the La increased. For the La=10% samples, light yield increased as Ce increased in the range of Ce=0.5-2.5% that corresponded with the increase of luminescent center of Ce. Decrease of LY due to concentration quenching was observed in the range of Ce4%.