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

作　　者：刘天航[1] 高勋[1] 刘泽昊[1] 郝作强[1] 孙长凯[1] 林景全[1] 

机构地区：[1]长春理工大学理学院,吉林长春130022

出　　处：《中国激光》2013年第11期108-111,共4页Chinese Journal of Lasers

基　　金：国家自然科学基金(61178022)

摘　　要：基于声学法对1064和355nm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，歼展了1064nm和355nm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1064nm和355nm激光产生的LSDW的点燃阈值范围分别为（3．95～13．05）×10^8W/cm^2和（3．14～10．07）×10^8W/cm^2。分析了激光波长因素对LSDW点燃阈值的影响。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） × 10^8 W/cm^2 for 1064 nm and （3.14- 10.07） × 10^8 W/cm^2 for 355 nm laser pulse. Furthermore, the wavelength effect on the ignition threshold of LSDW is analyzed.

关 键 词：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 

分 类 号：O536[理学—等离子体物理]