激光诱导等离子体屏蔽冲击波演化过程

Evolution Process of Laser Induced Plasma Shielding Shock Wave

开展了激光诱导等离子体屏蔽冲击波演化过程研究。利用光学阴影成像诊断技术,分析了纳秒激光透过玻璃聚焦在铝靶表面上分别产生的等离子体与冲击波碰撞的时间和空间演化过程。随着玻璃与铝靶间距增加,冲击波碰撞时间增加。研究结果表明,冲击波相互碰撞时本身并不发生相互作用,而是等离子体与冲击波发生作用,出现冲击波波前畸变甚至破碎现象,存在等离子体屏蔽冲击波过程,最后探讨分析了等离子体屏蔽冲击波物理机制。

The evolution processe of laser induced plasma shielding shock wave is studied. The temporal and spatial evolution processes of the plasma and shock wave are investigated, when nanosecond laser focused on the surface of the aluminum target through the glass, using optical shadow imaging diagnostic techniques. The collision time of the shock waves increases with the distance hetween the glass and the aluminum target. Experimental results demonstrate that the shock waves do not interact with each other but interact with the plasma in the collision, and the shock wave front distortion or even broken will exist, the shock wave is shielded by the plasma. And the physics mechanism of plasma shielding shock wave is analyzed.