基于BIXS方法的气体中高浓度氚在线测量技术

On-Line Measurement of High Concentration Tritium Based on BIXS Method

工艺气体中高浓度氚的在线测量要求探测器具有体积小、密封性好、稳定性高等特点。针对该需求,本工作基于氚β射线诱发X射线谱测量方法(BIXS)建立了高浓度氚在线测量实验系统,采用PENELOPE程序建立了理论计算模型,对系统中5个关键参数进行了设计优化,搭建了1.77 mL小体积BIXS实验系统,使用含氚的氢氩混合气体对实验系统进行了响应能谱测量,并对获得的BIXS能谱谱形进行了初步分析。实验结果表明,对于含氚的氢氩混合气体,BIXS系统重复测量结果显示全谱计数率偏差<0.8%,Ar的Kα峰计数率偏差<1.3%,Au的Mα峰偏差<3.8%,整体稳定性较好;不同压强下BIXS实验系统测量结果显示,BIXS能谱总计数率、Ar的Kα峰强度以及轫致辐射谱强度随压强增加呈线性上升趋势,但Au的Mα峰强度在该气氛下几乎不随氚的分压改变。

The high concentration tritium on-line measurement in tritium processing system requires the detector to have the characteristics of small volume,good sealing and high stability.Therefore,the on-line tritium measurement system is estabilished based onβ-ray induced X-ray spectrometry(BIXS)in this paper.The key parameters of this system was optimized by PENELOPE code.And the system is built and the volume of BIXS measurement chamber is 1.77 mL.The response of this system was evaluated by using hydrogen and argon mixed gas containing tritium.The results of repeated experiments show that the deviations of total counting rate of BIXS spectra and the characteristic X-ray of Ar and Au are less than 0.8%,1.3%,3.8%,respectively.In addition,the counting rate of BIXS spectra,characteristic peak of argon and bremsstrahlung linearly increase with pressure,however the intensity of characteristic peak of Au hardly changes with the tritium partial pressure in this atmosphere.