基于聚偏二氟乙烯压电传感器,对铜靶材中纳秒激光脉冲诱导的冲击波传播过程进行了实验研究,给出了铜靶材内冲击压强随激光脉冲能量和靶材厚度的变化规律.实验结果表明:500 m J激光脉冲能量作用到2 mm厚的铜靶材产生的冲击压强达到2.1 MPa;激光脉冲能量从200 m J增加到500 m J,在铜靶材厚度为2和4 mm条件下,冲击压强分别增加了162%和231%;而当铜靶材厚度从2 mm增加到6 mm时,在400和500 m J激光脉冲能量作用下,铜靶材内冲击压强分别降低了32%和49%.
In this paper, the shock waves induced by a nanosecond pulsed laser in copper target are studied and the relative pressures of shock waves are measured by using the piezoelectric polyvinylidene fluoride piezoelectric sensors. The evolutions of the relative pressures of shock waves with laser pulse energy and target thickness are discussed. Experimental results show that the pressure of shock wave is 2.1 MPa when the nanosecond pulsed laser with an energy of 500 mJ irradiates on a 2 mm thick copper target. When the laser energy increases from 200 to 500 m J, the pressures of shock wave can increase 162% and 231%, with the target thickness values being 2 and 4 mm respectively. But when the thickness of the copper target increases from 2 to 6 mm, the pressures of shock waves with laser pulse energies of 400 and 500 mJ are reduced by 32% and 49%, respectively.