Far-wing profile of photoabsorption spectra of Na(3s–3p) atoms perturbed by helium

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Atomic, molecular, and optical physics, 2008-09, Vol.41 (17), p.175102-175102 (8)
• Main Authors: Alioua, K, Bouledroua, M, Allouche, A R, Aubert-Frécon, M
• Format: Article
• Language: English
• Subjects: Ab initio calculations; Atomic and molecular physics; Atomic properties and interactions with photons; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Chemical Physics; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Intensities and shapes of atomic spectral lines; Line shapes, widths, and shifts; Physics; Self-consistent-field methods
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/41/17/175102

The far wings of the sodium spectra arising from the collisional broadening of the D lines by ground helium atoms are investigated theoretically. The required X2Sigma+, A2Pi and B2Sigma+ potential-energy curves and transition dipole moments have been generated from ab initio CASSCF-MRCI calculations to determine, within the framework of the semiclassical and full quantum-mechanical approaches, the temperature-dependent photoabsorption spectra. The profile is dominated by the free-free transitions at all temperatures ranging from 500 K to 3000 K and the computations show the existence of a satellite structure in the blue wing attributed to the X - > B transitions. The satellites occur around the wavelength position 520 nm when the calculations are performed classically and around 528 nm when they are performed quantum mechanically. The results are in good accordance with those produced by other theoretical and experimental works.