Blast-Wave Energy Conversion Processes in Air-Breathing RP Laser Propulsion

Abstract

The energy conversion processes in producing plasma by focusing a laser pulse have been investigated. A TEA CO₂ laser was used to produce plasma in quiescent air at reduced pressures and a M=2 flow. The laser supported detonation wave and the shock waves driven by plasma expansion were visualized by the shadowgraph method. The energy conversion efficiency in producing a blast wave was estimated from the shadowgraphs. As a result, in an air atmosphere, the efficiency was found at 0.4±0.1 in the case of 10J laser pulse input, and was 0.6±0.1 in the case of 4J input. Although the efficiency was not affected by the M=2 flow, it was decreased with the decrease in the ambient pressure.