THE GROUND STATE AND LOW-LYING EXCITED STATES OF THE HELIUM ATOM IN DENSE PLASMA

In this paper, the energy eigenvalues of the helium atom and the helium-like ions up to Z=5 in dense plasma are investigated with screened interaction potentials using Debye-Hückel model and exponential cosine screened Coulomb potential using variational Monte Carlo method. The calculations which are carried out in this paper are based on using trial wave functions with different asymptotic behaviors, classified as polynomial correlation, exponential decreasing, and exponential increasing functions. Furthermore, the low-lying excited states of the helium atom were investigated under the same model potentials using trial wave functions for the lowest four excited states, corresponding to the configurations 1s2s and 1s2p. Interesting results are obtained in comparison with results obtained by using other trial wave functions.