激光推力器喷管热防护实验研究

 基于激光推力器喷管热烧蚀因素分析，初步提出了反射式和吸收式两种喷管热防护方法，并相应设计了两种喷管。以10 kW级脉冲式CO₂激光器为光源，三次反射激光推力器为对象，进行了两种方式下两种喷管的热防护初步实验研究。结果表明：两种喷管均发生不同程度烧蚀，与相对聚焦位置和激光作用时间有关；反射式热防护通过喷管光学表面对透射激光能量进行二次聚焦，以及良好的循环冷却，可能成为将来激光推力器喷管热防护的备选方案之一。

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 CO_2 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 developed in the future.