%0 Journal Article %K ablation %K laser %K laser ablation %K laser-ablation %K vaporization %K plasma %K nanosecond %K nanosecond laser %K plasma shielding %K preferential vaporization %A Xianglei Mao %A Wing-Tat Chan %A Manuel Caetano %A Mark A Shannon %A Richard E Russo %B Applied Surface Science %D 1996 %F Laser %G eng %P 126-130 %R 10.1016/0169-4332(95)00420-3 %T Preferential vaporization and plasma shielding during nano-second laser ablation %V 96-98 %8 04/1996 %X

Preferential removal of components from mixed material targets and plasma shielding are studied by using inductively coupled plasma-atomic emission spectrometry (ICP-AES) during UV nano-second laser ablation. The ICP emission intensity for Cu and Zn during ablation of brass samples varies versus laser power density. A model using thermal evaporation and inverse Bremsstrahlung processes is presented. The model shows that plasma shielding occurs at approximately 0.3 GW/cm2, in agreement with experimental data for change in the mass ablation rate. The good agreement of model and experimental data suggest that thermal effects are important during nano-second laser ablation for power density less than 0.3 GW/cm2.