Properties of a spherical stratified gas discharge

Experimental data are obtained on the conditions for the stratification of spherical direct-current discharges and on the properties of the strata. Th e experiments were aimed at studying discharges in both molecular and inert gases at low pressures and were carried out with a steel chamber whose wal l served as a cathode. An anode was placed at the center of the chamber. Th e discharge stratification was observed to be especially pronounced in medi a containing a small admixture of the vapor of a high-molecular substance ( e.g., acetone). In discharges in pure inert gases, no strata were observed. The current-voltage characteristics of discharges at different pressures w ere obtained. The discharges were found to be unsteady: current pulses with a duration of about 1 microsecond and a characteristic repetition rate of about 1 kHz were detected against a steady current background and were foun d to correlate with the pulses of the integral emission from the discharge. The radius of each of the strata was determined as a function of its numbe r and of the gas pressure and discharge current. The radial profiles of the time-averaged floating potential were measured in experiments with stratif ied discharges and with uniform discharges in argon. (C) 2000 MAIK "Nauka/I nterperiodica".