多电极测氡脉冲电离室对氡探测效率的模拟研究

脉冲电离室的多个因素(几何形状、体积和电极数目)影响着其测氡探测效率,现采用蒙特卡罗程序Geant4模拟了这些因素与测氡探测效率之间的关系。模拟结果表明:脉冲电离室测氡探测效率与其表面积体积比成反比关系;同一表面积体积比下脉冲电离室测氡探测效率与其电极数目(或电极/电离室体积比)成负指数关系。该模拟结果的有效性为文献报道的多电极脉冲电离室测氡实验结果所检验,可用于提高多电极脉冲电离室测氡探测效率的快速优化设计。

Simulation Study on Radon Detection Efficiency of the Ion Pulse Ionization Chamber with Multi-electrode Structure

Many factors (geometric shape, volume and number of electrodes) of the pulse ionization chamber affect its radon detection efficiency. The relationship between these factors and the radon detection efficiency is simulated by the Monte Carlo program Geant4. The results show that:the detection efficiency of ion pulse ionization chamber for measuring radon is inversely proportional to its surface area to volume ratio. Under the same surface area to volume ratio, the detection efficiency of pulse ionization chamber for radon measurement has a negative exponential relationship with the number of electrodes (the volume ratio of electrodes to chamber). The simulation results are verified by the experimental results in the literature, and can be used for the rapid optimization design to improve the radon detection efficiency of the ion pulse ionization chamber with multi-electrode structure.