CR-39应用于中子探测的化学蚀刻条件优化研究

An experimental study on optimal chemical etching condition for CR-39 used in neutron detection

CR-39化学蚀刻的主要影响因素有蚀刻温度、蚀刻液种类和浓度以及蚀刻时间等。本研究选用英国TrackAnalysis Systems公司的CR-39，采用正交法对蚀刻温度、蚀刻液浓度、蚀刻时间进行试验研究，并与公司推荐化学蚀刻条件下的径迹图像、径迹密度进行对比，得出的优化蚀刻条件是蚀刻温度为85℃、NaOH蚀刻液浓度为7 mol-L，蚀刻时间为90 min。实验同时发现蚀刻温度是这三个因素中对化学蚀刻后净径迹密度影响最大的因素，而蚀刻时间的影响最小。该研究为CR-39应用于中子探测提供了更好的蚀刻条件，节省了实验时间。

Background CR-39 is an important solid-state nuclear track detector, which is widely used in neutrondetection and environmental monitoring. Chemical etching is usually used to expand the track in the application ofCR-39. Purpose： The paper deals with chemical etching conditions of CR-39 and aims to get an optimal etchingcondition. Methods： The three major factors to CR-39 chemical etching are etching temperature, etching time andetchant concentration （NaOH solution was used in this paper）, and they were studied by an orthogonal design test.The etching temperature was 75 ℃, 85 ℃ and 95 ℃, respectively; the etching time was 90 rain, 170 min and240min, respectively; the etchant concentration was 5.5 mol·L-1, 6.25 mol·L-1, and 7 mol·L -1, respectively.Experimental data were analyzed with modified Grubbs rule and compared with the recommended chemical etchingcondition. Results： The optimal chemical etching condition for CR-39 used in neutron detection is 7 mol·L-1 NaOHsolution at 85 ℃ for 90 min, which is better than the recommended chemical etching condition. Conclusion： Anoptimal chemical etching condition for CR-39 used in neutron detection was provided, and the condition was withless time than the recommended one.