吸气式激光推进中空气对CO2激光的吸收系数计算

Calculation of Absorption Coefficient of CO2 Laser by Air in Air-breathing Laser Propulsion

比较分析了吸气式激光推进中空气对CO2激光的3种吸收机制,列出了相应的吸收系数计算公式。通过计算发现,自由-自由吸收对应的逆韧致吸收系数占总吸收系数的比例几乎达到80%,即在较强的激光辐照作用下,由于电子温度很高,高温空气主要通过逆韧致方式吸收入射激光能量。计算结果可以用于吸气式激光推进的能量沉积过程研究。

Three absorption mechanisms of CO2 laser by air in air-breathing laser propulsion are analyzed and compared,and corresponding absorption coefficient expressions are listed separately.Through calculation it is found that the proportion of inverse bremsstrahlung absorption coefficient to total absorption coefficient is almost up to 80%.That is,under stronger laser irradiation,for the electronic temperature is very high,and the incident laser energy is mainly absorbed by high-temperature air through inverse bremsstrahlung.Results of calculation can be applied in deposit process of air-breathing laser propulsion.