Influence of Preionization on the Irradiation Characteristics of High-power Xenon Flashlamps

To deepen our knowledge of preionization discharges in high-power xenon flashlamps, we investigated the influence of preionization discharge on the irradiation characteristics of xenon flashlamps through electrical measurement, radiant efficiency measurement, high-speed photography, and radiant spectra measurement. The experimental results showed that comparing with flashlamps working with only main discharges, working in preionization mode with a proper time interval between main discharge and preionization discharge can increase the radiant efficiency of xenon flashlamp by 3.8%~5.1%. However, when the time interval is small, current in the preionization circuit will oscillate and could decrease the lamp's radiant efficiency by over 10% compared with the maximum radiant efficiency. Additionally, preionization discharge also helps to improve the radiant spectral characteristics, which benefits matching the radiant spectra with working medium of laser as well as the gain of amplifiers.