High-Frequency (MHz) Ignition of Commercial Flash Lamps for Solid State Lasers

Abstract

A multiple (from 20 to 3 kV) decrease in the ignition threshold of commercial flash lamps for solid-state lasers under HF pum** at a megahertz frequency has been detected. It has been found that, upon water cooling of the lamp, the cathode glow is developed during HF pum** on both electrodes, in contrast to the pulsed ignition for the capacitance discharge, since both electrodes alternately act as the anode and cathode. At the stage of ignition development, the Faraday dark space is observed in the middle part of the lamp and its size decreases with the increasing HF pum** voltage until the lamp is ignited by a solitary streamer between the electrodes. It has been established that the main factors that determine a decrease in the full lamp ignition threshold are the high-frequency field amplitude and the coolant impedance, as well as the ignition range. The HF ignition of the lamp with a discharging gap of up to 60 cm (an ignition threshold of ~5 kV) has shown the universality of the developed ignition mode.