Evaluation of β-γ Coincidence Measurement System Using Plastic Scintillation β-ray Detector Developed for the Determination of γ-ray Emission Probabilities of Short-lived Nuclides

Abstract

For precise determination of γ-ray emission probabilities of short-lived nuclides whose half-lives are less than a few minutes, a β-γ coincidence measurement system has been developed which uses a plastic scintillator as a β-ray detector. The system was applied to a measurement of the absolute β-ray emission probability of 1,779keV β ray in ²⁸A1 (Ti/2=2.24min), whose γ-ray emission probability is well known. The uncertainty of the measured γ-ray emission probability was smaller than 2%. Performance of the β-γ coincidence system has been demonstrated for a short-lived nuclide, and the details of the corrections have been analyzed.

KEYWORDS:

• absolute gamma-ray emission probability
• short-lived nuclides
• beta-gamma coincidence methods
• plastic scintillator
• germanium detector
• aluminum 28
• dead-time
• corrections
• high counting rates
• performance
• errors