Striation Formation during Steady-State Glow Discharge

Abstract

The formation of striations in a normal glow discharge has been correlated with a relaxation-type phenomenon occurring at the cathode dark space-negative-glow interface and caused by cathode instabilities. A beamlike stream of electrons, in excess of that number necessary to maintain the normal glow brought about by cathode instabilities, is postulated to cross the cathode-fall region and to interact with neutrals in the negative glow causing a surplus of positive ions at the interface between the cathode dark space and the negative glow. This group of positive ions constitutes a positive striation which in turn is accelerated toward the cathode. The experimentally observed times for these striations to cross the cathode-fall region give a velocity of approximately 104 cm/sec, which is in good agreement with other observations of positiveions striation velocities.