中国激光, 2013, 40 (11): 1103006, 网络出版: 2013-10-24
声学法判断金属铝板靶激光支持爆轰波的点燃阈值
Determination of the Ignition Threshold of Laser Supported Detonation Wave of Aluminum Using Acoustic Method
激光技术 激光等离子体 激光支持爆轰波 声学诊断 点燃阈值 laser technique laser-induced plasma laser supported detonation wave acoustic diagnosis ignition threshold
摘要
基于声学法对1064 nm和355 nm激光脉冲作用金属铝板的激光支持爆轰波(LSDW)点燃阈值进行了研究,理论分析了激光等离子体声波压强与冲击波的膨胀速度关系,开展了1064 nm和355 nm激光作用铝板靶的实验研究。实验结果表明等离子体声波存在时间为毫秒量级,其峰值强度呈指数衰减趋势。实验发现激光作用铝板产生的等离子体声波信号幅度随激光功率密度的增加而增加,但是在激光功率密度增加的过程中等离子体声波峰值强度出现两次跃变,由此判断出1064 nm和355 nm激光产生的LSDW的点燃阈值范围分别为(3.95~13.05)×108 W/cm2和(3.14~10.07)×108 W/cm2。分析了激光波长因素对LSDW点燃阈值的影响。
Abstract
The ignition threshold of laser supported detonation wave (LSDW) of aluminum generated by 1064 nm and 355 nm laser pulses is studied using acoustic method. The relation between the pressure of laser-induced plasma acoustic wave and the expansion velocity of shock wave is analyzed theoretically. Then the experimental research of aluminum target irradiated by the laser with the wavelength of 1064 nm and 355 nm is developed. The experimental results show that the lifetime of plasma acoustic wave is on the millisecond order, and the peak intensity of plasma acoustic wave decays exponentially. It is found in the experiment that the signal amplitude of plasma acoustic wave generated by the laser irradiation on aluminum target increases with laser power density increasing. However, the peak intensity of plasma acoustic wave appears jump stage twice while laser power density increases. From this it can be determined that the ignition threshold range of LSDW is (3.95~13.05)×108 W/cm2 for 1064 nm and (3.14~10.07)×108 W/cm2 for 355 nm laser pulse. Furthermore, the wavelength effect on the ignition threshold of LSDW is analyzed.
刘天航, 高勋, 刘泽昊, 郝作强, 孙长凯, 林景全. 声学法判断金属铝板靶激光支持爆轰波的点燃阈值[J]. 中国激光, 2013, 40(11): 1103006. Liu Tianhang, Gao Xun, Liu Zehao, Hao Zuoqiang, Sun Changkai, Lin Jingquan. Determination of the Ignition Threshold of Laser Supported Detonation Wave of Aluminum Using Acoustic Method[J]. Chinese Journal of Lasers, 2013, 40(11): 1103006.