Spatial distribution of electron temperature of laser-induced aluminum alloy E414d plasma

Parameters of the laser-induced aluminum alloy E414d plasma are studied. The Local Thermodynamic Equilibrium (LTE) is proved valid for the electron number density (1.9×1018 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.