NONPERTURBATIVE TIME-DEPENDENT THEORY OF 2-ELECTRON ATOMS IN STRONG LASER FIELDS

This work deals with the fundamental problem of the behavior of the tw o-electron atom under intense laser fields. We present a broad scope o f calculations and results and, we believe, the first ATI spectrum, in He and Mg atom, beyond the single active electron model in a fully ti me-dependent nonperturbative calculation. For He, we perform calculati ons both on a two-electron basis with configuration interaction where both electrons are allowed to be excited, and on a frozen core basis. The comparison is a direct measure of the effect of correlation under strong fields. The results for Mg shows that the method also opens a w ay to the study of atoms with much stronger electron correlation in in tense laser fields.