Effects of Target Thickness on Propulsion Performance in Laser Micro Confinement Ablation

The thickness of the ablation layer to influence the propulsion performance in laser micro ablation propulsion is researched. It is found that the thicker layer result in the stronger confinement of the plasma expansion leads to higher impulse coupling coefficient and ablation efficiency, and therefore a high impulse coupling coefficient of 2750 μN/W is observed. The better propulsion performance could be got by the high power density condition with YAG laser, and a high ablation efficiency of over 40% is obtained. This is an enhancement of almost 10 times compared to that in the low power density condition with diode laser.