Ar+CH_4混合气体中电子漂移速率的双栅法测量  

Measurement of Electron-Drift Velocity in Ar+CH_4 Mixtures With Double-Grid Method

作　　者：张家国[1] 张国辉[1] 陈金象[1] 

机构地区：[1]北京大学物理学院重离子物理研究所和核物理与核技术国家重点实验室,北京100871

出　　处：《原子能科学技术》2008年第8期691-696,共6页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(10575006);科技部中俄资源环境领域重大问题合作研究项目(2005CB724804)

摘　　要：提出了一种快速、准确测量电子在气体中漂移速率的新方法。通过分析电子在双栅电离室中两个栅极上产生的感应信号波形来确定电子漂移的起止时刻,从而得出电子在一定约化场强下的漂移速率。采用数据采集卡(waveform digitizer)对电离室的极板信号进行记录。测量了电子在8种混合比例的Ar+CH4气体中漂移速率随约化场强的变化曲线。通过分析实验数据,得到任意混合比例的Ar+CH4气体中电子漂移速率的计算公式。A new method for rapidly and accurately measuring the electron-drift velocity was described in detail. This method is based on analyzing the induced signals of doublegrid of an ionization chamber to determine the electron-drift time between the two grids. The waveform digitizer was employed to record pulses from the two grids of the ioniza- tion chamber. The electron-drift velocity was measured as the function of the reduced electric field for 8 different ratios of argon-methane mixtures. A formula for calculating electron-drift velocity in any ratio of argon-methane mixtures was presented.

关 键 词：电子漂移速率 双栅电离室 数据采集卡 

分 类 号：O572.212[理学—粒子物理与原子核物理]