Collisional-radiative and average-ion hybrid models for atomic processes in high-Zplasmas

A new time-dependent atomic model is presented. In the model, called the hybrid-atom model (HAM), the energy-functional form of the population probability obtained from the average-ion model is used to estimate the level population of ions having charge different from the average ion. In medium-Z plasmas HAM gives results similar to the collisional-radiative (CR) model. The required computation time is comparable to the average-ion model even for high-Z plasmas. In these plasmas the CR model becomes impracticable. Though the model partly uses the average-ion model, the x-ray emission calculated is significantly different.