Variation of the transition energies and oscillator strengths for the 3C and 3D lines of the Ne-like ions under plasma environment

Abstract

We present the results of a detailed theoretical study which meets the spatial and temporal criteria of the Debye-Huckel (DH) approximation on the variation of the transition energies as well as the oscillator strengths for the 2p 5 3d 1 P 1 → 2p 6 1 S 0 (3C line) and the 2p 5 3d 3 D 1 → 2p 6 1 S 0 (3D line) transitions of the Ne-like ions subject to external plasma. Our study shows that the redshifts of the transition energy follow the general scaling behaviors similar to the ones for the simple H-like and He-like ions. Whereas the oscillator strength for the 3C line decreases, the oscillator strength for the spin-flipped 3D line increases as the strength of the outside plasma increases. As a result, their ratio is amplified subject to outside plasma environment. We further demonstrate that the plasma-induced variation between the relative strength of the 3C and 3D transitions is mainly due to the spin-dependent interactions which dictate the mixing of the 1 P 1 component in the 3 D 1 upper state of the 3D transition. In addition, we are able to find that the ratio between the relative oscillator strengths of the 3C and 3D lines in the presence of the plasma to their respective plasma-free values varies as a nearly universal function of [(Z − 9.2)DZ] −1.8 , with Z the nuclear charge and D the Debye length. The results of this study should be of great help in the modelling and diagnostic of astrophysical plasmas as well as laboratory plasmas.

Energy Shift of the Atomic Emission Lines of He-like Ions Subject to Outside Dense Plasma

“…An analytical formula for the leading order of general transitions between two hydrogenic orbitals was given as Equation (7) in [25]. However, additional effects, such as the relativistic effects [26] as well as the electronelectron correlation [25], may also affect the change in the respective energies due to the outside plasma. As a result, the resulting transition energy could either be redshifted or blueshifted.…”

“…Individually, CSF is a linear combination of the Slater determinants of the atomic orbital functions corresponding to the electron configurations included in the calculation. Again, more details of the calculational procedure were presented in our earlier works [3,5,25,26,29].…”