Helium Breakdown Characteristics under 100 kHz Range Pulsed Voltages in Partial Vacuum for Point-to-point Electrode Geometry

In this paper we present our work on breakdown studies conducted in helium at partial vacuum conditions for a point-to-point electrode setup. A high frequency pulsed voltage signal is applied across the electrodes and the voltage-current characteristics are observed. The applied signal consists of a train of square pulses in the frequency range of 50 to 200 kHz with 50% duty cycle and rise/fall times in the range of 20-30 ns. These studies were conducted to understand and compare the role of the pulse repetition rate in electrical breakdown initiation in low pressure conditions. Preliminary data of voltage and current waveforms, along with the light emission data are presented. The optical data collected by a PMT (Photo Multiplier Tube) as a function of the time is presented in comparison to the varying voltage.