Dimensional analysis and laser-produced plasmas

A schematic overview of the heating and hydrodynamical behavior of laser-produced plasmas is provided by using an extensive set of self-similar models. The range of validity of the self-similar models is derived in conjunction with the definition of natural boundaries among them. It is proved that over these boundaries, a continuous transition for the scaling laws of all plasma variables takes place. This important result allows for the division of the parameter space of laser-produced plasmas (for example, in terms of the plasma temperature and time) into different regions where the associated self-similar regime can be understood as an intermediate-asymptotic description followed by the plasma evolution. The scaling laws derived initially by dimensional analysis have direct physical interpretation, allowing for the identification of the primary physical processes underlying the plasma behavior and affording a better understanding of the plasma evolution. Nonequilibrium states and thermal emission are allowed for in the hydrodynamic processes. This technique is applied together with simple thermodynamical models for the evaluation of an Au target irradiated by an Nd laser