Generalized Oscillator Strengths for Dipole 2s→(2p, 3p, 4p) and Quadrupole 2s→(3d, 4d) Excitations of Spherical Compressed Atomic Lithium Immersed in a Quantum Plasma

The generalized oscillator strengths (GOSs) associated with the dipole 2s→2s⁰(2p, 3p, 4p) and quadrupole 2s→2s⁰(3d, 4d) excitations of a lithium atom confined within a spherical cavity and embedded in a quantum plasma are investigated within the Bethe-Born approximation. Radial wavefunctions are obtained from Bahar’s numerical solution of the radial Schr？dinger equation using the More General Plasma Model Potential (MGPM), which incorporates length screening, oscillatory screening, and linear correction effects. The analysis, performed for a fixed confinement radius under different plasma conditions characterized by the screening parameters $a$ , $b$ , and $D$ , reveals the combined influence of these parameters on the GOSs. The quadrupole GOS amplitudes decrease with decreasing ($D$ ) and increase as $a$ and $b$ decrease. Moreover, the parameter $b$ generates additional maxima, while the peak positions shift toward higher $q^2$ values with increasing $a$ and toward lower $q^2$ values with increasing $D$ . Similar behavior is observed for the dipole excitations, where plasma screening has its strongest effect in the low squared momentum transfer region and becomes negligible at higher momentum transfers. Higher excited states are found to be more sensitive to the quantum plasma environment than lower excited states, although some transitions exhibit non-monotonic behavior due to the interplay between plasma screening and spherical confinement.