应用于时间投影室的光刻一体化微结构探测器性能研究

Studies on the Performance of the Photolithographic Micro-Pattern Gas Detector Applied to Time Projection Chamber

时间投影室(Time Projection Chamber,TPC)可以同时测量时间和位置信息,光刻一体化微结构探测器作为其读出探测器具有抗干扰性强、均匀性好、透过率高的特性。为了寻找探测器最佳的工作条件,使用55Fe豁免源测试了实验室研制的流气型光刻一体化微结构探测器在不同Ar和CO_(2)比例下的增益、能量分辨率以及在最优气体比例下的均匀性。根据测试结果,探测器在85%Ar和15%CO_(2)混合气体下增益达到最大,超过104,增益均匀性为3.26%,达到目前国际上光刻微结构探测器同等水平。对雪崩区厚度分别为100μm、160μm和220μm的3种光刻一体化微结构探测器增益及其均匀性进行比较,雪崩区厚度为160μm的探测器是更优的选择。研制了密闭型微结构探测器,通过测试证明,可以在常温常压下正常工作21天以上。闭气模式下探测器的增益与温度呈负相关,与流气模式下相反,两种模式下的能量分辨在短期内都不受小范围温度变化影响。

The time projection chamber(TPC)is capable of simultaneously measuring both time and position information,while the photolithographic micro-pattern gas detector,as the readout detector of TPC,can offers strong anti-interference,good uniformity,and high transmittance.In order to find the most suitable gas ratio as the working condition for the photolithographic micro-pattern gas detector of TPC,a 55Fe calibration source was used to measure the gain,energy resolution,and uniformity of the photolithographic micro-pattern gas detector independently developed by the laboratory under different Ar(argon)and CO_(2)(carbon dioxide)ratios.According to the test results,the detector achieved its maximum gain of over 104 and gain uniformity of 3.26%in a gas mixture of 85%Ar and 15%CO_(2),with reaching the current international equivalent level.Furthermore,the photolithographic micro-pattern gas detector with avalanche zone thickness of 160μm was identified as giving the optimal gain and uniformity after testing three avalanche zone thicknesses of 100μm,160μm,and 220μm.A sealed micro-pattern gas detector has been developed,which demonstrated normal operability at room temperature and pressure for more than 21 days.The gain of the sealed micro-pattern gas detector is inversely correlated with temperature,which is opposite to that under flowing gas conditions.However,the energy resolution in both modes is not affected by small-scale temperature changes in the short term.