Cold-cathode gas-discharge modulator power tube

A cold-cathode gas-discharge tube were developed for pulse modulation of voltage in such devices as generators of pulse currents and voltages with capacitive or inductive energy storage. The operation is based on magnetic control of space ionization, with the glow region under conditions corresponding to the left-hand branch of the Faschen curve. These features ensure reliable and stable performance, a cold cathode without heater filament saving both energy losses and warmup time. The basic structure of this tube is a coaxial configuration of cylindrical electrodes, with the cathode outside and the anode inside. The electrodes are both made of Kh18N10T stainless steel, both 2 mm thick and, respectively, 120 and 100 mm in diameter. A longitudinal magnetic control field is produced in the interelectrode space and, as the magnetic induction reaches its critical level, discharge is ignited just after a positive voltage pulse was applied to the ignition stabilizing circuit. The maximum anode voltage is 15 kV, current pulses of 20 to 200 microsec duration is generated and a current of at least 1 kA is interrupted under full voltage at repetition rates of 0.1 to 200 Hz with a fall time not exceeding 5 microsec. The performance characteristics of this tube are superior to those of the GMI-37A hot-cathode pulse modulator tube, including a longer than 1000 h life.