激光烧蚀硬铝产生等离子体温度和力学效应测量

 为了研究激光推进技术中激光与材料相互作用的机制，获取等离子体状态参数及力学参数，采用Nd:YAG被动调Q固体激光器烧蚀硬铝，通过激光诱导等离子体光谱技术测得等离子体光谱和温度，由冲量摆测得力学参数。实验结果显示：在激光功率密度0.534×10⁸ W/cm²时，靶材表面的等离子体温度在等离子体辐射过程中呈二次曲线衰减；改变靶材等离子体点燃阈值附近的激光功率密度时，随着功率密度的增加，等离子体温度、冲量耦合系数也随着增大，当功率密度达到靶材的等离子体点燃阈值时，各参数达到最大，此后随着功率密度增加，由于等离子体对能量的屏蔽作用，导致靶材表面的等离子体温度降低，等离子体获得的动能减少，靶材耦合的冲量降低。

Temperature and mechanics effect measurement of plasma induced by laser ablating hard aluminum

In order to study the mechanism of laser interacting with materials in laser propulsion technique, the parameters related to plasma state and mechanics are needed. The plasma spectra and temperature are measured by laser-induced plasma spectroscopy, the mechanical parameters are obtained by impulse pendulum, as a passive Q-switch solid laser is ablating hard aluminum. The experimental results demonstrate that the plasma temperature on material surface declines with time in quadratic curve mode under laser power density of 0.534×108 W/cm2. Changing the laser power density around the material plasma ignition threshold, it is found that the plasma temperature and the momentum coupling coefficients increase with the increase of the power density, they reach the maximum as the power density re