Modeling of vaporization processes of resonant laser ablation

Abstract

Resonant laser ablation (RLA), which combines laser ablation (vaporization) and resonance ionization spectroscopy simultaneously with a single laser, can be used as a simple analytic technique of trace elements with high sensitivity and elemental (isotopic) selectivity for solid samples. To predict typical RLA phenomena for metal samples, in particular the dependence of its sensitivity and selectivity on the incident laser power, we propose a theoretical model coupling the vaporization and ionization processes on the sample surface. In the vaporization process, the particle flux balance is calculated between the vapor and solid phases of sample materials through the ablated sample surface, and then the ionization probability in the net particle flux is estimated as two components from the resonant and non-resonant (or thermal) ionization processes. In comparison with some basic experiments, the present model calculation gives comparatively good agreement with resonant and non-resonant ion yields near the threshold laser power of laser ablation.