原子能科学技术2025，Vol.59Issue(5)：1120-1125,6.DOI:10.7538/yzk.2024.youxian.0643
反宇宙射线内充气正比计数管测量85Kr的活度
Radioactivity Measurement of 85Kr by Using Anti-cosmic Ray Internal Gas Proportional Counter
梁建峰 1刘志超 1解峰 1代义华 1师全林 1王春杰 1李雪松 1关清帝 1姜文刚 1余功硕1
作者信息
- 1. 西北核技术研究所,陕西 西安 710024
- 折叠
摘要
Abstract
85Kr is a noble gas radioactive nuclide with a half-life of 10.75 years,and it decays by emission of beta rays associated with weak gamma rays.Most of the 85Kr released into the atmosphere is artificially produced by neutron induced fission reactions,and it plays an important role in atmospheric environmental monitoring,detection of clandestine production of fissile materials,and verification of atmospheric transport model.Low-level detection of 85Kr is therefore required.Internal gas proportional counter(IGPC)is one of the primary techniques to measure 85Kr.However,studies about anti-coincidence measurement based on IGPC mostly focused on the measurement of 37Ar,and few studies about 85Kr were reported.In this paper,an anti-cosmic ray IGPC system was established to improve the detection sensitivity of 85Kr.A quasi-4π well-type plastic scintillator surrounding the inner IGPC was used as an anti-coincidence detector to actively shield the background arising from cosmic rays.Compared with the non-anticoincidence spectrum,the background count rate of the anti-coincidence spectrum decreases from 3.64 s-1 to 0.182 s-1.The activity concentration of 85Kr was measured using length compensation method,and the detection efficiency of the system was calibrated to be 95.8%.The minimum detectable activity of 85Kr of about 7 mBq was achieved within 24 hours,which effectively improves the measurement sensitivity of 85Kr.关键词
85Kr/内充气正比计数管/反宇宙射线/低水平测量Key words
85Kr/internal gas proportional counter/anti-cosmic ray/low-level activity measurement分类
核科学引用本文复制引用
梁建峰,刘志超,解峰,代义华,师全林,王春杰,李雪松,关清帝,姜文刚,余功硕..反宇宙射线内充气正比计数管测量85Kr的活度[J].原子能科学技术,2025,59(5):1120-1125,6.
