Current Distribution Over the Hollow-Cathode Surface for a Low-Pressure Glow Discharge

The results of an investigation of a low-pressure hollow-cathode glow discharge are presented for the conditions where the cathode cavity depth is comparable with the cavity diameter. The data on current distribution over the hollow-cathode surface using sectioned electrodes are obtained and the length of the cathode sheath is measured. It is shown that discharge can be sustained in the regimes of suppressed glow discharge and ordinary glow discharge. For the regime of a suppressed glow discharge the main fraction of the total discharge current closes to the cathode section nearest to the anode. For the regime of an ordinary glow discharge, when the cavity depth is equal to cavity diameter, the discharge current is uniformly distributed over the cathode surface. The discharge parameters and the values of the cathode sheath are estimated using the model of hollow-cathode discharge sustainment. The model agrees well with the experimental data.