Energy relaxation of intense laser pulse-produced plasmas

We describe a collisional radiative model (CRE) of homogeneously expanded nickel plasmas in vacuum. The CRE model is coupled with two separate electron and ion temperature magneto-hydrodynamic equations. On the output, the model provides the temporal variation of the electron temperature, ion temperature, and average charge state. We demonstrate the effect of three-body recombination (proportional to NeTe-9/2) on plasma parameters, as it changes the time dependence of electron temperature from t(-2) to t(-1) and exhibits a pronounced effect leading to a freezing feature in the average charge state. In addition, the effect of the three-body recombination on the warm up of ions and delaying the equilibration is addressed.