Development of a beta-gamma discrimination type plastic beta-ray spectrometer

2015 Fiscal Year Final Research Report

• Project/Area Number: 25287045
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Tohoku University
• Principal Investigator: Orihara Hikonojo 東北大学, サイクロトロン・ラジオアイソトープセンター, 名誉教授 (00004432)
• Co-Investigator(Kenkyū-buntansha): SAKEMI Yasuhiro 東北大学, サイクロトロン・ラジオアイソトープセンター, 教授 (90251602)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ベータ崩壊 / β－γ分別型β線分光器 / プラスチックシンチレーター / 放射性セシウム-134 / 放射性セシウム-137 / 放射性ストロンチウム-90 / 永年平衡放射性崩壊 / 食品放射能検査

Outline of Final Research Achievements

Development of β-ray detection device has been desired for inspecting the environmental pollution by the radioactive nuclides emitted as the results of the accident of the first nuclear power plant of Fukusima occured along with the great earthquake which covered over East Japan. Especially, detection of β-decay dominant 90Sr nucleus which has half-life of 28.78 years is important. To dispel the social fear of radiation, it is required for the detection-system to measure radioactivity of the object in a time as short as a few hours with a accuracy of less than 100Bq/kg. β-ray spectrometer, consisting of two pieces of plastic scintillator forming a counter-telescope, has been developed. A portable-type β-ray spectrometer has been developed and fabricated. By the aids of coincidence measurements with two plastic scintillators, background-free counting is available for detection of low-level emission of the β-rays as low as 10 Bq/kg requiring several hours operation.

Free Research Field

原子核（実験）