提出了一种在高气压下电离室离子漂移速度的测量方法,进行了理论分析,搭建了实验测量系统。利用DDC112电流积分放大器对充有4MPa氙气的高压气体电离室输出电流脉冲信号分别进行等间隔积分时间和步进积分时间采集测量,根据理论分析对测量数据分别进行二次和三次曲线拟合。通过拟合曲线系数间的比例关系计算出离子漂移时间,根据电离室结构和工作条件计算出4MPa氙气中氙离子迁移率为0.018 1~0.019 6cm2.V-1.s-1,并外推计算出0.1MPa氙气中氙离子迁移率为0.72~0.78cm2.V-1.s-1,与文献资料中的测量结果一致。
A method of measuring ion drift velocity on the condition of high gas pressure was mentioned,and theoretic analysis was done.An experimental measurement system was also built.A DDC112current integral amplifier was used to measure the output current pulse signal of ionization chamber filled with 4MPa xenon by fixed integration time integral measurement and stepping integration time integral measurement.The quadratic curve and cubic curve were fitted by experimental data based on the theoretic analysis.The ion drift time was calculated by proportional relationships of curve coefficient.According to the structure and running conditions of ionization chamber,the xenon ion mobility in 4MPa xenon was calculated and the value is 0.018 1-0.019 6cm 2 · V-1 ·s-1.The xenon ion mobility in 0.1MPa xenon was calculated by extrapolation method and the value falls within the interval 0.72-0.78cm 2 ·V-1·s-1,that is in good agreement with the data from literatures.