Vacuum arc behavior and its development process under micro-second scale

A lot of work had been made in the vacuum arc in power frequency. But there are few research reports about high-frequency vacuum arc. In this paper, the arc appearance and development process have been studied under 250 kHz. A compact resistance-inductance-capacitance (RLC) series resonant circuit was designed to generate high-frequency vacuum arc between plate electrodes in a detachable vacuum chamber. High voltage probe and current transformer were used to measure arc voltage and arc current. Intensified charge-coupled device (ICCD) were adopted to observe the arc behavior under the different frequency. Just like the arc development in commercial frequency, at the beginning, the arc is ignited at the triggered point and then the arc became brighter and its diameter also increased. As time went by, the arc is diffusing in the whole gap but the arc is not extinct completely when the discharge current cross zero. At the same gap distance, the arc burns more fiercely as the charge voltage rises. With the gap distance increases, the diffusion between vacuum gap become more intense but the discharge current remains unchanged.