Development of surface discharge along a dielectric with large dielectric constant in gas in the nanosecond range

The discharge from a metallic edge along the surface of a dielectric with dielectric constant of the order of 100 or larger is investigated. The dependences of the rate of expansion of the discharge, the time lag, and the volt-ampere characteristics are obtained for exposure times of the order of 10^-9 sec for plates made of barium titanate, titanium dioxide, and steatite ceramicwith thickness of the order of 1 mm or less at voltages up to 1.5 kV of different polarity. The average rate of expansion of the figure of luminosity after a time of ≤3 nsec is equal to 10⁶ cm/sec in order of magnitude. It is shown that from a negative point the discharge is initiated by the self-electron emission current, while from a positive point it is initiated by the self-ionization current. The basic equations are given for a commutator utilizing surface discharge from a large number of points.