Non-LTE ionization and energy balance in high-Z laser plasmas including two-electron transitions

We describe a new non-LTE average-atom-kinetics model of plasmas in which the two-electron transitions of autoionization and its inverse, resonant capture, play a dominant role in establishing ionization and energy balance. We show that, compared with a familiar collisional-radiative-equilibrium model for laser-produced gold plasmas: (1) the two-electron transitions force recombination of the plasma with decreasing density, and (2) the two-electron transitions nevertheless further act to greatly increase the radiative emissivity of the plasma.