Static and dynamic polarizability for C2+ in Rydberg states

Abstract

This work presents results from a non-perturbative calculation of dynamic polarizability of C III ions in 1s22sns (1Se) Rydberg states. We employ a two-state model for dressed atomic states to investigate the effect of the frequency-dependent polarizability of optically dressed 1s22sns(1Se) states (n = 5 − 12) on transitions to nearby states (1s22pns(1P1o)). Our model calculation results indicate that the resonance structure of the polarizabilities is entirely captured by the transition terms whereas the free electron polarizability only provides a smooth background. The resonance structure is evident in the plots and the widths increase with increasing principal quantum number. This work refers to highly excited 1s22sns (1S) Rydberg states, embedded in the electric dipole field of the 2s – 2p core transition in Li-like C3+ ion. The contributions of the individual transitions to the static polarizabilities of these Rydberg states are obtained from the use of the sum-over-state method. To this aim, both the C2+ ground state and the C3+ target state energies have been carefully calculated based on the configuration interactions method implemented in the General-purpose Relativistic Atomic Structure Package. Agreement is reasonably good with existing data wherever available. These results are believed to be the first such values for this system and will be important for ionic spectroscopy and plasma diagnostics.