Study of Relativistic excitation energies and transition data of X–ray and EUV transitions in Be-like ions

Abstract

In the present work, fine structure energies, transition wavelengths, transition rates, oscillator strengths and line strengths have been presented for lowest 40 levels of Be-like Fe, Os to Hg ions by using GRASP2K. We have analyzed the effects of core-valence (CV) correlations in excitation energies as a function of active set. We accomplish that effects of core-valence correlations are necessary to attain accuracy and convergence in excitation energies. We have compared our presented excitation energies of Be-like Fe with available theoretical and experimental energies and found good agreement. But due to unavailability of data for Be-like Os to Hg ions for comparison, we have calculated excitation energies from flexible atomic code (FAC). We show that magnetic multipole transitions (M2) have effective contribution in lifetime of 2s3p 3P2o and 2p3d 3P2o. We demonstrate that transitions of Be-like ions among lowest 40 levels mainly occurs in Hard X-ray (HXR), Soft X-ray(SXR) and Extreme Ultraviolet (EUV) regions.