Dynamic polarizability of an atomic ion within a dense plasma

We analyze the influence of plasma electron density on frequency-dependent linear field-response behavior of an atomic ion embedded in a dense plasma medium. The frequency-dependent atomic response, characterized by the dynamic dipole polarizability alpha(d)(omega) as a function of the angular frequency. of the time-dependent field, is estimated here up to the first pole of alpha(d)(omega) on the omega axis (corresponding to the lowest resonance transition 1s(2) S-1 -> 1s2p P-1) for the ground state 1s(2) S-1 of a two-electron atomic ion Ne8+ (Z = 10) at different plasma electron densities, as a typical example, employing the time-dependent coupled Hartree-Fock scheme within the framework of the ion-sphere model. It is observed that, owing to plasma density-induced enhancement of alpha(d)(omega) at every., the pole position of alpha(d)(omega) on the. axis retracts toward the origin. This indicates a density-induced lowering (redshift) of the corresponding transition energy that conforms to experimentally observed trends. The polarizability calculation suggests a density-induced drop in the 1s(2 1)S. 1s2p P-1 absorption oscillator strength in the atomic ion within dense plasmas.