Discharge mechanism in gases in the subnanosecond region.

Abstract

The mechanisms of spark generation which produce luminous and electric pulses of the order of subnanoseconds in a gas at a high pressure are analyzed. The classical mechanisms, which account for regenerative processes initiated by the photons produced during the avalanches of electrons, cannot explain the generation of 10“ electrons in 0.3 nsec, which were experimentally detected when using our generator. In this work, the experimental results are interpreted by means of a model which considers the equilibrium surface shape of the liquid as the resultant of an increase in the field near the electrodes up to 109-1010 V/cm (the surface shape is determined by the superimposed effect of the electric field and the surface tensión). With a field of this magnitude, electrons are produced at the cathode in numbers large enough to explain the experimental results. In agreement with the model proposed, pulses of 10-10 sec duration can only be obtained with liquid electrodes in gases at a high pressure.