Formulation of the streamer breakdown criterion and its application to strongly electronegative gases and gas mixtures

Following an examination of the definition of the effective coefficient of ionisation\(\bar \alpha\), a reformulation of the streamer breakdown criterion is undertaken. The application of this criterion to strongly electronegative gases and gas mixtures is considered, and a figure of merit is introduced to describe dielectric behaviour. By considering both ideal and practical electrode systems, this parameter is shown to be of fundamental importance with respect to the evaluation of the breakdown characteristics of such gases. Its value can be determined from a precision measurement of the linear portion of the Paschen curve.