1999 年 75 巻 10 号 p. 1138-1144
The collisional radiative model of multiple-charged ions of high-Z elements is described. Characteristic features of the level structure and atomic processes, and approximate methods to calculate ion abundance and level populations are presented. In the development of an atomic model, a large number of energy levels and collisional radiative rates are calculated using the atomic data codes. The usefulness of the super configuration model in constructing a simpler atomic model is explained using the results of a collisional radiative model for soft x-ray lasers.