In this paper we used one-dimentional non-LTE laser irradiated code to simulate the laser-produced plasmas conditions of thin middle Z targets with high intensities (about 10¹³W/cm²)irradiation.Following physical processes are considered; bremsstrahlung,radiative ionization,collisional ionization by electrons and their inverse processes, Compton scatterion. Fokker-Planck approximtaion is used in Compton scattering; The thermal flux limits are taken for electrons and ions in the calculating and the multigroup flux-limited diffusion approximation is taken for the radiative transport equations.Using average-atom model to calculate the population probabilities of atoms. Laser absorption via inverse bresstr-ahlung is considered to be the most important in our simulation.Using, laser beams with intensities 5×10¹³W/cm² and 1×10¹⁴ W/cm², λ_L=0.53μm, τ=450ps to irradiate thin Se target from single-side and double-sides separately, the computational results for laser-produced plasmas conditions are good agree with experimental results.

In this paper, the rate equetions of average atom model and hydrogen-like ions are discussed. At very high ionization they are equivalent. The emphasis is put on the investigation of using average atom model to calculate population inversions. Stripping the inner electrons with X-ray and recombining them to outer shell by three-body recombination, we can obtain the population inversions. Some conditions and results are given.