摘要
在背景气压为 8× 10 - 3 — 10 0Pa范围内 ,通过测量脉冲激光烧蚀平面Al靶产生的等离子体辐射谱的时间分辨特征 ,比较空间不同点辐射的飞行时间轮廓的相对延迟 ,从而得到辐射粒子速度及其空间分布 .利用绝热膨胀的理论和激波模型分别对背景气压小于 0 .6Pa的结果和 5Pa时的结果作了分析 ,并得出激波的波面基本上为柱对称 .
With the ambient gas pressure in the range from 8×10 -3 to 10 2 Pa, Q-switched YAG laser ablates plane aluminum target and plasma are produced. Optical emission spectroscopy is used to carry out time-resolved analysis of atomic particles. Using the resonance transition of Al I 396.1 nm (3p 2P-4s 2S), the spatiol velocity distribution of Al I has been obtained under the laser energies of 160 mJ/pulse when the ablating size is about 200 μm. The velocity is at the order of 10 6 cm/s. The distribution of velocity in spatial is approximately constant when the ambient pressure is in the range of 8 ×10 -3 - 6×10 -1 Pa and is decreasing nearly in exponential law when the ambient pressure is 5 Pa. When the pressure increase to 100 Pa, the rising front of the time profile becomes too blurred to measure the delay time exactly. The results are explained by using adiabatic expansion theory for pressure less than 0.6 Pa and shockwave model for 5 Pa respectively.
出处
《原子核物理评论》
CAS
CSCD
北大核心
2002年第2期206-208,共3页
Nuclear Physics Review
基金
教育部优秀教师资助计划项目
教育部高等学校骨干教师资助计划 (GG 14 0 10 736 10 0 2 )
兰州重离子加速器国家实验室原子核理论研究中心基金~~
