Propagation of a Glow Discharge into the Annular Gap between the Discharge Tube Wall and the Cathode

Abstract

Time-resolved spectroscopic measurements and electrostatic probe measurements were used to study that part of a high-voltage pulsed glow discharge in hydrogen that propagated into the annular gap between the cathode and the Pyrex discharge tube wall. The spectroscopic and probe measurements revealed that a luminous front and a potential wave started to propagate into the annular gap at the same time as the electric field in the cathode fall region at the face of the cathode reached its maximum value. The dependence of the propagation velocity on the discharge parameters is presented and the importance of the secondary emission at the wall of the discharge tube is established as a factor in the propagation of the discharge.