CO_(2)预处理对CR-39中子个人剂量计增敏特性的研究  

Sensitization effects of CR-39 neutron dosimeters pre-treated with CO_(2) under various pressures and durations

作　　者：赵阳[1] 王勰[1] 夏斌元 李硕 王亮[1] 彭微颖 刘柯钊[1] 熊忠华[1] ZHAO Yang;WANG Xie;XIA Binyuan;LI Shuo;WANG Liang;PENG Weiying;LIU Kezhao;XIONG Zhonghua(Institute of Material Research,China Academy of Engineering Physics,Mianyang 621700,China)

机构地区：[1]中国工程物理研究院材料研究所,绵阳621700

出　　处：《核技术》2024年第10期115-125,共11页Nuclear Techniques

摘　　要：本文研究了CO_(2)预处理对CR-39探测器灵敏度及径迹特征形成影响。以经^(252)Cf中子源照射的CR-39探测器为研究对象,通过统计探测器记录径迹数与径迹尺寸,分析了不同CO_(2)预处理时间和压力对CR-39探测器灵敏度及径迹尺寸分布的影响规律。研究结果表明:经CO_(2)预处理后CR-39探测器灵敏度及最大径迹尺寸得到显著提高,灵敏度最大提升870%,最大径迹尺寸由20μm增大至40μm;探测器灵敏度与预处理压力时间存在特定正相关关系,灵敏度随CO_(2)压力线性增大;最大径迹尺寸在40μm附近增长达到饱和,继续提高预处理时间和压力,径迹包含的中子能谱特征不再被保留;本实验获得的CO_(2)预处理下CR-39形成径迹保留能谱特征的最佳灵敏度为6.25 tracks·mm^(-2)·mSv^(-1)。这项研究对于提高CR-39中子个人剂量计灵敏度及选择合适CO_(2)预处理条件方面具有重要意义,同时也提供了一种在提升径迹可读性时保留径迹能谱特征信息的预处理方法,可应用于基于中子能谱特征优化中子个人剂量当量评估。[Background]Etched track dosimeters(ETDs)based on CR-39 foils are the most frequently used passive detectors for neutron personal dosimetry at various nuclear facilities.That applying a pre-treatment in carbon dioxide(hereafter,CO_(2) pre-treatment)can improve the CR-39 detection sensitivity and enlarge the tracks is extremely valuable and warrants further investigation.[Purpose]This study aims to investigate the effect of CO_(2) pre-treatment on the sensitivity and the track size distributions of CR-39 detectors,and to obtain an optimal CO_(2) pre-treatment condition.[Methods]A parametric study was conducted to evaluate the effect of CO_(2) pre-treatments at different pressures and durations on CR-39 detectors.The detectors were firstly irradiated by a standard 252Cf neutron source,delivering a personal dose equivalent Hp(10)of 2 mSv.Then,the detectors were subjected to carbon dioxide treatment prior to undergoing chemical etching for durations ranging from 6 h to 168 h at partial pressures varying between 0.1 MPa to 1.6 MPa.Finally,the correlation between detector sensitivity and pre-treatment condition was obtained by analyzing the number of registered tracks and track size distribution under each pre-treatment condition.[Results]The obtained results indicate that the CO_(2) pre-treatment significantly improves sensitivity and maximum track size,with the sensitivity increasing by up to 870%and the maximum track size expanding from 20μm to 40μm.The sensitivity increases linearly with pre-treatment pressures,and the saturation point of the maximum track size appears around 40μm.As the time and pressure continue to increase,the neutron spectrometry information contained in the track size distributions will be erased,the optimal sensitivity for CR-39 to retain the spectral information in the track size distributions is 6.25 tracks·mm-2·mSv^(-1).[Conclusions]This study is of significance for improving the sensitivity of CR-39 detectors in neutron dosimetry and selecting CO_(2) pre-treatment conditions,providin

关 键 词：CR-39探测器 CO_(2)预处理 增敏作用 中子剂量 径迹尺寸分布 

分 类 号：TL815.7[核科学技术—核技术及应用]