Modeling of SQS Propagation Induced by Alpha Ray in Gas Counters

With reference to optical images of the self-quenching streamer (SQS), we have already proposed a possible mechanism of SQSs induced by α-rays. To check the validity of the mechanism, we have been designing a model for the computer simulation of the SQS propagation based on the newly proposed mechanism. In the present modeling, in order to calculate the growth of the discharge, a set of continuity equations for electrons and ions is numerically solved in a two-dimensional space. An electron supply process from the α-ray ionization track is assumed to be the dominant process for the streamer development instead of the conventional electron-supply process which is based on the photo ionization in the gas media. The streamer propagation is simulated under the concept of “two-region model”. A first comparison between computed and experimental results shows a good agreement.