Nonlocal thermodynamic equilibrium self-consistent average-atom model for plasma physics - art. no. 026401

A time-dependent collisional-radiative average-atom model is presented to s tudy statistical properties of highly charged ion plasmas in off-equilibriu m conditions. The time evolution of electron populations and the electron c ovariance matrix is obtained as approximate solutions of a master equation. Atomic structure is described either with a screened-hydrogenic model incl uding l splitting, or by calculating one-electron states in a self-consiste nt average-atom potential. Collisional and radiative excitation/deexcitatio n and ionization/ recombination rates, as well as autoionization and dielec tronic recombination rates,: are formulated within the average-configuratio n framework. Local thermodynamic equilibrium is obtained as a specific stea dy-state solution. The influence of atomic structure and the role of autoio nization and dielectronic recombination processes are studied by calculatin g steady-state average ionization and ionization variance of hot plasmas wi th or without radiation field.