摘要
为配合222Rn/220Rn子体连续测量仪的研制,开展了用222Rn/220Rn子体测量仪采集α能谱的峰重叠因子研究。本研究以国家标准222Rn室与220Rn室分别作为纯222Rn子体与220Rn子体测量环境,用222Rn/220Rn子体连续测量仪采集222Rn子体与220Rn子体α能谱,求得各α能峰的重叠因子。研究结果表明:非真空条件下220Rn子体发射的8.78Me Vα粒子慢化到7.69Me Vα能谱峰计数区,以及222Rn子体发射的7.69Me Vα粒子慢化到6.00Me Vα能谱峰计数区的概率较大,可取0.0335、0.1791作为表征α能谱峰重叠情况的峰重叠因子θ1、θ2典型值。而8.78Me Vα粒子慢化到6.00Me Vα能谱峰计数区的概率非常小,其峰重叠因子θ3可以忽略;同一张滤膜重复多次使用并未导致峰重叠因子显著的变化,且不同滤膜的峰重叠因子的差异在2%以内,对测量仪测量误差的贡献有限。
In order to smoothly develop the αspectroscopy -based continuous measurement instrument of 222^ Rn/220^ Rn progeny, the reseach of peak overlap factor ofαspectroscopy achieved by the continuous measure-ment instrument was performed.The 222 ^Rn chamber( national standard) , 220 ^Rn chamber were used as measure-ment environment of pure 222 ^Rn, 220 ^Rn progeny respectively, and the peaks overlap factors have been calculated byαenergy spectrums of 222 ^Rn( or 222 ^Rn) progeny, which was gathered from the measurement environment by the continuous measurement instrument of 222 Rn/220 Rn progeny in the radon laboratory of university of south chi-na.The results showed that:Under the non vacuum condition, the probability of 8.78 MeVαparticle emitted by 220Rn progeny ThC′(212Po) slowing down to the 7.69 MeVαparticle counts region, and the 7.69 MeV al-pha particleemittedby 222Rn progeny RrC′(214^Po) slowing down to the 6.00 MeVαparticle counts region can not be ignored.But the probability of 8.78 MeVαparticle slowing down to the 6.00 MeVαparticle counts re-gion is very small;A membrane filter reuse don’ t result in peaks overlap factorsθ1 ,θ2 andθ3 significant chan-ges, and can take 0.0335, 0.1791 and zero as typical values respectively;The contribution to the instrument measurement error from membrane changing is limited, since the different membrane peaks overlap factor differ-ences within 2%.
出处
《核电子学与探测技术》
CAS
北大核心
2015年第2期176-179,共4页
Nuclear Electronics & Detection Technology
基金
国家自然科学基金(11375083
11475082)
湖南省衡阳市科技计划(2013KJ30)资助