Study of recombination processes during the expansion phase of titanium-plasma produced by picosecond Nd:glass laser radiation

An investigation of the plasma dynamics during its expansion phase is presented. The analysis is based on a numerical model, which considers the adiabatic plasma expansion as well as a three-body recombination process as the main source for plasma cooling. The result shows that a fast energy transfer between electrons and ions is observed during the early stage of plasma expansion. Three-body recombination process exhibits a pronounced effect leading to a 'freezing' feature in the average charge states of heavy particles. This process seems to control the fractional population of ionic species at the end of the expansion phase