A general parametric model for the gain of gas avalanche counters with particular attention to non-cylindrical geometries

A simple, general parametric model of the avalanche process in gas counters is described. Applicable to all the common forms of gas avalanche detector—wire, microstrip, point anode and parallel gap, the model describes the gain process in terms of two pseudo-physical constants which are effectively invariant over the working range of any given detector configuration. For counter operation over a wide range of conditions (e.g. very different gas pressures) the model is extended so that four parameters are required to model the gain. Applications of the model to the characterisation, operation and design of a variety of counter types are given.