利用金属外探针探测激光等离子体的电学效应  

Electricity effect detection of laser plasma with a metal probe

作　　者：纪运景[1] 卞保民[1] 陆建[1] 王春勇[1] 

机构地区：[1]南京理工大学信息物理与工程系,江苏南京210094

出　　处：《红外与激光工程》2009年第5期830-833,共4页Infrared and Laser Engineering

基　　金：南京理工大学科研发展基金资助项目(AB96246);南京理工大学研究生发展基金资助项目

摘　　要：利用Nd:YAG脉冲激光烧蚀Cu靶,实验研究了空气中激光等离子体电学效应在金属探针上产生的电信号的形成机制与演变规律,对探针与烧蚀点之间的距离对电信号的影响进行了测试。结果表明:信号结构与探测距离密切相关,探针距离较近时(<3mm),信号具有正负双极分布结构,距离较远时(>3mm),则仅表现为负脉冲单峰结构,且信号幅值与探针距离之间满足Ia∝d-2。对该信号进行详细分析后得出:从等离子体区域出射的高速电子和离子到达探针是信号形成的主要机制,并对信号幅值随探针距离的变化关系进行了合理解释。The form mechanism and evolution rule of electrical signal induced by the laser plasma effect were investigated with a tiny metal probe during Nd：YAG high-power pulse laser ablation on copper in air. And the effect of distance from probe to ablaten point on the electrical signal was tested through experiment. The experimental results show that the signal distribution is closely dependent on the detection distance. The distribution of signal wave is positive-negative double peak in close detection distance （〈3 mm）, and is negative single peak at long distance （〉3 mm）. In addition, the peak value of the signal -2 can be gained from the probe distance as follows： Ia∝d^-2 . It is considered that the electrical signal is formed of high-speed electrons and ions arriving to probe from laser plasma after analyzing the signal. And the variety relation between peak value of signal and probe distance is explained reasonably.

关 键 词：激光等离子体 金属探针 电信号 探测 

分 类 号：O53[理学—等离子体物理]