Nd:YAG连续激光辐照铝合金旋转抛物面的温度效应

为了研究激光推进中激光作用反射面后的温度效应,采用自行设计的温度测量系统对不同激光功率辐照下的旋转抛物面铝合金靶的表面温度进行了测试,得到了不同条件下温度-时间关系曲线。结果表明,激光吸收率随激光入射角的增大而增大;罩面上的表面温度与位置相关,自辐照点至径向各点上的温度符合高斯分布,激光辐照点与其它各点呈现明显不同的升温和降温特点;激光辐照停止约数秒后,旋转抛物面表面上各点的温度趋于一致,之后按同一种热扩散方式和降温曲线变温。

Temperature Effect of Aluminum Alloy Paraboloid under the Irradiation of Continuous Nd:YAG

The surface temperature of a parabolic reflector under laser irradiation for propulsion has direct influence to the reflectivity, lifetime and many other properties, such as optical and mechanical properties, of the reflector and, therefore, to its performance of laser propulsion. In this work the temperature vs. time curves have been measured by irradiating an Al alloy parabolic reflector with a 1064 nm Nd:YAG CW laser at different powers. The results show that the laser absorptivity increases with the incidence angle; the surface temperature depends on the radial distance from irradiating position according to the Gaussian distribution function. The irradiation position has different rising and lowering temperature features with other positions. The temperatures on the surface tend to be the same and follow the same thermal diffusion and temperature lowing curve since several seconds after switching off the laser irradiation.