Numerical analysis of TOF measurements in pulsed laser ablation

The results of numerical simulation of pulsed laser ablation both in vacuum and into a background gas are presented. The influences of different proce sses, such as time evolution of the surface temperature, interspecies inter actions (elastic collisions, recombination-dissociation reaction), interact ion with an ambient gas, and excitations-relaxation processes on time-of-fl ight (TOF) distributions are examined. Experimentally obtained time-of-flig ht distributions are further analyzed, based on the results of numerical si mulation. It is found that with the aid of numerical results one can explai n not only the shape of the TOF distribution, but also the distance depende ncy of its maximum position (mean delay time). In addition, the mechanisms leading to the appearance of bimodal time-of-flight distribution are reveal ed. The study presents particular interest for the analysis of experimental results obtained during pulsed laser ablation.