Experimental investigation on thermal protection for nozzle of laser thruster

Based on analysis for nozzle thermal ablation, reflecting and absorbing thermal protection approaches were presented to provide thermal protection for nozzles. Two types of corresponding nozzles were designed. Initial investigation was carried out on the two types of thermal protection of the two nozzle types, in which a pulsed 10 kW CO2 laser and a three-reflection laser thruster were employed. The results showed that the nozzles were ablated to different extent, depending on the relative focus position, working time etc. A reflecting thermal protection approach, in which direct absorption of the laser energy was reduced by the optical surface of the nozzle and the penetrated energy was refocused to improve energy transferring efficiency, with good circular cooling, is prospective to be d