High power AC modulator

A new modulation technique has advanced the state of the art in pulsed high power short arc xenon flashlamps. The design of a 50 kW pulsed average power xenon arc lamp was predicated on the development of a push-pull type of modulator to enable heat to be equally extracted from both electrodes. Normally, arc lamps are pulsed from a dc source resulting in high anode temperatures and consequent deterioration. On the other hand, the lamp cathode is less of a problem due to the benefit of electron cooling. Hence, a modulator designed to operate in a push-pull fashion allows the heat load on the lamp electrodes to be balanced. The advantages to be realized include a lower total thermal load on the anode and two paths (both electrodes) for heat injection. The modulator design is presented along with preliminary test results on developmental 50 kW average power lamps which have been pulsed to 100 kW average pulse power on a 50 percent duty cycle.