Doubly excited states in hot and dense plasmas: Beryllium-like ions for Z=4−10

Abstract Effects of the hot and dense plasma on the doubly excited states (DES) of the four-electron beryllium-like ions (BLI) with Z varying from 4 to 10 have been investigated by applying the stabilization method. The Debye–Huckel model has been used to describe the effective potential in the plasma. The four-electron ions are treated as an effective three-body problem by means of the method of model potential. One, four and five DESs lying above the 1s 2 2p threshold are found to exist in the ions having Z = 4 , Z = 5 and Z = 6 − 10 respectively. For the plasma-free case our results for the energy and width of the DESs are in agreement with the available results in the literature. A detailed study is made on the changes of energy and width of the DESs of the ions with varying plasma screening strength. Particular emphasis is given to explore the effects of the plasma on the whole sequence of ions.