激光驱动飞片速度的理论分析

激光驱动飞片技术是模拟微流星体/空间碎片对航天器外露材料/部件超高速撞击，用于开展撞击累积损伤效应与材料性能退化的研究，也是进行航天器在轨寿命预估和空间碎片防护研究的重要技术手段。飞片速度是衡量激光驱动飞片技术水平的关键性参数之一。文章从Lawrence改进的Gurney模型出发，着重分析了激光输出能量、脉宽、聚焦光斑大小以及飞片靶厚度等参数与飞片速度大小的关系，提出激光驱动飞片技术中提高飞片速度的主要途径:其他条件一定时，薄靶较厚靶更易获取高速飞片；小光斑较大光斑更易获取高速飞片；长脉宽高能激光器或短脉宽低能激光器比较适合获取高速飞片。以上结论对从试验上获取高速飞片具有重要指导意义。

Theoretical analysis on the velocity of laser-driven flyer

The laser-driven flyer (LDF) technique is widely used to simulate micro meteoroids and orbital debris (M/OD) with respect to their hypervelocity impacting effects. The flyer velocity is one of the key parameters of LDF and it is influenced by many factors. This paper analyzes the relationships between the flyer velocity and the laser energy, the width of laser pulse, the diameter of laser focal spot, and the flyer thickness based on Lawrence-Gurney model. Higher velocity flyer is obtained by using thinner target or smaller laser focal spot. At the same time, long pulse-high energy or short pulse-low energy laser are preferred in those experiments. These relations may help to obtain high velocity flyers in the LDF experiment.