On ionization dynamics of metal targets irradiated by high-contrast relativistic-intense laser pulses

We perform simulation of irradiation of metal targets by high-contrast relativistic-intense laser pulses. The results of modeling show that the locally equilibrium mean charge of ions calculated with the aid of the Thomas–Fermi model is in good agreement with the model that considers time dependable collisional-radiative population kinetics of ground and excited states of ionized atoms. The main reason for this is a high density of plasma free electrons in the case of interaction of the high-contrast laser pulse with a step-like plasma density profile. (paper)