The electron avalanche and its development

Summary

A single electron avalanche can be detected by the following methods: 1) by means of a cloud chamber; 2) by measuring the potential drop over a series resistance which is composed of the rapid electron component and the slow ion component; 3) by detecting the light quanta, emitted especially from the head of the avalanche, with a photo-multiplier. If we enlarge the multiplication expad, the following processes happen:a) the number of ions moving to the cathode and the number of light quanta increases;b) the space charge field increases. Processa) starts the spark by avalanches going to and fro (Townsend mechanism). Processb) becomes important when expad becomes exp 20, where the streamer mechanism starts. These points are discussed in detail.