Investigation of Mist Cooling for the Electra KrF Laser Hibachi

Abstract

An experimental investigation has been conducted to examine nozzle-generated, gas/liquid mist cooling with ultra-thin, evaporating liquid films as a cooling mechanism for the Electra KrF laser dual-foil hibachi structure. Experiments have been conducted within the Electra KrF laser using a prototypical dual-foil hibachi structure cooled with either forced convection air or an air/water mist. Test runs up to 10,000 shots at 5 Hz have been successfully performed. Mist cooling results for a moderate air velocity of 15 m/s and a water mass fraction of 15% show that the hibachi foils can be maintained below 150°C when operated at full power pulsed conditions. The data indicate that mist cooling can decrease foil cooling time constant by nearly an order of magnitude compared to forced convection using air only.