Development of a remote alpha/beta monitoring system for under high gamma background

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15482
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 31010:Nuclear engineering-related
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Morishita Yuki 国立研究開発法人日本原子力研究開発機構, 福島研究開発部門 福島研究開発拠点 廃炉環境国際共同研究センター, 研究職 (20631401)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: αβγ線弁別型検出器 / パルス波形弁別 / プルトニウム / ラドン子孫核種

Outline of Final Research Achievements

In this study, a radiation detector capable of discriminating alpha particles, beta particles, and gamma rays was developed by combining the developed detector with a personal dust monitor. The developed detector consisted of two scintillators and a Silicon Photomultiplier (SiPM). The first layer of the scintillators was stilbene for detecting alpha particles and beta particles. The second layer of the scintillators was a Ce-doped Gd3Al2Ga3O12 (GAGG) scintillator for detecting gamma rays. 5.5 MeV alpha peak can be confirmed in the measured alpha energy spectrum. Since beta particles are continuous energy, a continuous energy spectrum was confirmed in the measured beta energy spectrum. A low energy part of 90Sr and a high energy part of 90Y were confirmed. The photopeak of 662 keV and the Compton continuum part were confirmed in the measured gamma energy spectrum. Alpha particles, beta particles, and gamma rays from the radon progeny can be simultaneously measured and discriminated.

Free Research Field

放射線計測

Academic Significance and Societal Importance of the Research Achievements

開発した小型ダストモニタは、γ線とα線β線が分離ができることから、高線量のγ線BG環境下でのα線、β線モニタリングに有用と考えられる。また、重量が2.0 kg未満であり、様々な自走式ロボットあるいは飛行ロボットに搭載し、人が立ち入れない環境での放射性物質のモニタリングに威力を発揮すると考えられる。