Putting pressure on Paschen´s Law

In the past few years the major concentration of research on electric breakdown is gases has been on identification of the basic processes of ionization in the electric field leading to the spark-over. Townsend¹ presented the model initially in 1900 and introduced several coefficients, characteristic of the ionization potential and the many secondary processes that contribute to ionization of the gas between electrodes. A review of the fundamental considerations of breakdown was given by Berg at the previous EI Conference.² This paper is intended to delve less into the mathematical derivations of the breakdown phenomena and limit discussion to the considerations of Paschen´s Law as observed experimentally at pressure well above the minimum.