激光诱导铝合金E414d等离子体电子温度的空间分布

摘要

采用调Q Nd:YAG脉冲激光诱导铝合金E414d,研究了等离子体的谱线强度、电子温度和电子密度.建立Al(Ⅰ)256.80 nm、Al(Ⅰ)308.21 nm和Al(Ⅰ)396.15 nm的波耳兹曼平面,实验发现距靶面高度1.5 mm处等离子体的电子温度最高.罗仑兹函数拟合Mg(Ⅰ)285.21 nm得到等离子体的电子密度是1.9×1018 cm-3,远大于局域热力学平衡所需的电子密度值9.8×1015 cm-3,证明实验得到的等离子体满足局部热力学平衡.%Parameters of the laser-induced aluminum alloy E414d plasma are studied. The Local Thermodynamic Equilibrium (LTE) is proved valid for the electron number density (1. 9 X 1018 cm-3) , inferred from the Lorentz fit of Mg ( I ) 285. 21 nm, is lager than the lower limit (9. 8×1015 cm-3) for LTE exists. The electron temperatures at different height are determined using the Blotzmann plot method with Al ( I ) 256. 80 nm, Al ( I ) 308. 21 nm and Al ( I ) 396. 15 nm. The electron temperature is maximum at the distance of 1. 5 mm above the target surface and it decreases both at the plasma edge and close to the target surface. The physical explanations for this spatial distribution are presented.