Prebreakdown phenomena in insulating gases. Evaluation of the time-to-breakdown

This work is a continuation of earlier work and deals with a study of the avalanche and streamer formation in insulating gases. The goal of this work is to develop and verify discharge models for practical insulating geometries on the basis of physical discharge processes. The work involves an experimental study of the electrical and optical discharge activity as well as two-dimensional (2-D) model simulations. In this paper we discuss the results with regard to the time-to-breakdown t/sub bd/ in nitrogen and dry air. It is shown how the time-to breakdown is influenced by the applied field, the initial electron number, the pressure and the pressure reduced field E/p. The time-to-breakdown curves simulated agree with experimental observations.