Collinear Double Pulse Nanosecond Laser-plasma Dynamics

Recent years, with the laser –induced plasma shock wave in laser shock peening, laser ignition, propulsion, laser plasma shock wave cleaning technology is widely used in areas such as been of great concern to national researchers. So for, national researchers to produce single-pulse laser induced plasma shock wave launched a lot of research, but for double pulse laser induced plasma shock wave accompanied by less research, due to its physical process is very complex, so we need to double characteristics of pulsed laser-induced plasma shock wave in-deep inquiry.In this paper, atmospheric conditions and double pulse laser induced plasma expansion dynamic of air and Al plasma shockwave has carried out extensive research. The main contents include:(1) Using PVDF piezoelectric film sensors under different pulse laser energy, the role of copper target nanosecond laser produced shockwaves, shockwave propagation in the copper target and obtain its impact pressure.(2) Using double-pulse nanosecond to study the effect of different pulse delay between the target and the aluminum target air shockwave produced plasma laser breakdown of air and irradiated aluminum target, using shadow imaging method, while the pre-pulse laser-produced plasma air the second laser beam generated lensing and laser-plasma interaction with different electron density plasma channels generated the corresponding instructions.(3) Using double-pulse nanosecond laser breakdown of air, using interferometry to study the laws of different air plasma shockwave pulse propagation delay under the circumstances, and given the delay spread under different conditions from the air plasma shockwave propagation velocity and shockwave frontier pressure curve for different pulse delay between double pulse and single pulse laser induced plasma accompanied by propagation of the shockwave propagation along explanation is given.