Silver plasma by pulsed laser ablation

A Nd : Yag laser was employed to irradiate thick silver targets in vacuum. The ion emission from the Ag plasma was detected in situ using a ring ion collector and an electrostatic ion energy analyzer which permitted measurement of the ion kinetic energy-to-charge state ratio. The total ion yield, the ion threshold fluence, the ion energy distributions and the mean temperature for the different ion charge states of the non-equilibrium plasma were investigated. The visible radiation emission spectrum, the light emission threshold, the electronic temperature and density were also investigated by using optical spectroscopy. Ex situ surface profile measurements, performed on the generated craters after the ablation process, permitted the evaluation of the ablation threshold fluence and performance of a comparison with a semi-empirical model.