The Researches On The Shock Wave Interaction Mechanisms With Laser Plasma

The shock wave is a mechanical stress wave propagating in medium.The strong air shock wave is formed during the bomb explosion process to the surrounding movement.When the expanded shock wave of high pressure meets the obstacles,so the attack target would suffered varying degrees damage or even threaten human life.In this paper,the shock wave interactions with laser plasma were investigated by optical shadow imaging method.The processes of the shock wave interactions with laser plasma,were obtained using single-beam nanosecond laser pulse focusing through glass to the surface of aluminum target and using two laser pulses generated the columnar plasma wall and air shock wave,respectively.The electron density distribution of columnar plasma wall was analyzed by laser induced breakdown spectroscopy.The physical mechanism of shock wave interaction with laser plasma was discussed.The research results shown that,when the shock wave contacted the plasma,the wavefront of the shock wave was distorted or even broken,the plasma would shield the shock wave expansion which decreased the expansion distance and speed.When the laser pulse energy of the plasma wall was increased and the distance between the air shock wave and the aluminum target was shortened,the shielding effect of the plasma wall on the air shock wave was enhanced.The electron density of the columnar plasma firstly increased and then decreased with the increase of the distance from the aluminum target.The maximum position of the electron density corresponded to the broken position of the air shock wavefront,which indicated that the shielding effect of the plasma on the shock wave depended on the electron density distribution inside the plasma.The research results on the shock wave interaction mechanism with laser plasma are of great significance to shield shock wave and reduce the harm of shock wave diffusion.