Formation stage of a high-voltage pulsed discharge in a long tube

A study was made of discharges in long tubes (d 60–132 cm) in hydrogen through an analysis of the oscillograms of the discharge current and voltage pulses and through a photometric study. As the pressure increases from 0.4 to 5 torr and as the overvoltage decreases from 290 to 90%, the step current I_st decreases, while the times t_d, t_st, and t_f, which characterize the formation stage, increase. It is thus possible that the step forms as a result of the conversion of the avalanche-streamer maximum at the beginning of the formation stage to a cathode-directed streamer. The value pd 300 torr · cm found under the experimental conditions of this study corresponds to a transitional discharge mechanism.Translated from Izvestiya VUZ. Fizika, No. 8, pp. 128–133, August, 1970.The authors thank A. Ya. Sytnik for assistance in the measurements.