激光烧蚀Cu靶产生等离子体紫外段发射光谱的研究

利用波长532nm,脉宽15ns的Nd:YAG 激光器作用于Cu靶上，研究了产生等离子体的紫外段（180 nm～300 nm）发射光谱。在局部热力学平衡条件下，采用Boltzmann图表法估算了等离子体的电子温度，得到了电子温度随时间和空间的变化，以及电子温度随激光能量密度的变化。结果显示，随着激光能量的变化，电子温度有一个极大值。随着时间的发展，电子温度先减小，而后增大，接着缓慢减小。随着距靶面距离的增加，电子温度呈下降趋势。

Ultraviolet spectroscopic study of laser-induced Cu plasmas

Ultraviolet (180 nm～300 nm) spectra of laser-induced Cu plasmas is studied using 532 nm, 15 ns pulses from a Nd:YAG laser. Boltzmann diagram method is used to calculate the electron temperature by assuming LTE conditions. The relations between electron temperature and laser fluence is acquired. Also space- and time-resolved measurements of electron temperature have been carried out using emission lines of copper plasma. The result shows that the temperature has a maximum value as laser fluence varies. Time evolutions of temperature are found to decay at early times, then a rise appears. After the rise, the temperature decreases at a slow speed. Spatial variation of temperature shows a flat drop as distances from the target surface increases.