TITLE:
Generalized Oscillator Strength of Valence-Shell Excitations of Atomic Sodium in Debye Plasma Within the Frame of Two Various Methods
AUTHORS:
Clément Diatta, Louis Gomis, Ibrahima Guèye Faye, César Martínez-Flores, Moustapha Sadibou Tall, Yandé Diouf, Rama Gomis, Mamadou Coulibaly, Ismaïla Diedhiou
KEYWORDS:
Generalized Oscillator Strength, Length Form, Restricted Hatree-Fock, Random Phase Approximation with Exchange, Debye-Hückel Plasma, Screening Effect
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.14 No.12,
December
27,
2024
ABSTRACT: The generalized oscillator strengths (GOSs) of 2p63s0 (3p, 4p, 5p, 6p) states excited from sodium ground state in Debye plasma, are studied by two kinds of theoretical approaches: the restricted Hartree-Fock (RHF) method and the random phase approximation with exchange (RPAE). Wavefunctions of the ground state and the excited states are calculated numerically from the RHF equation, employing the local density approach for exchange interaction including, in extension, plasma screening effects. The GOSs have been computed by using these wavefunctions. The results of RHF and RPAE calculations of the GOS for different Debye lengths have been reported for sodium dipole excitation to 3s0 (3p, 4p, 5p, 6p). We show, in this study, that RPAE results for values of Debye length D = 30, 100, ∞ are in excellent agreement with those found by other authors. The results of RPAE calculations show that correlation effects are quite significant around the maxima GOS for the excitations to 3s0 (4p, 5p, 6p) but are found to have no great influence in the GOS for the dipole excitation to 3s03p. We find that the amplitude of the GOS has noticeably been reduced in going from higher to lower Debye length. We’ve observed here that the peak of the GOS shifts towards a small momentum transfer when the value D = 20 a.u is taken. These results show an important influence of the Debye plasma screening interactions on the GOS as the screening Debye length is decreased.