International Workshop on Atomic Interactions in Laser Fields - Abstracts
E. Paul-Kwiek
Institute of Theoretical Physics and
Astrophysics, Gdansk University, 80-952 Gdansk, Poland
e-mail:
fizek@univ.gda.pl
Absorption coefficient, linear and circular polarizations of collisionally redistributed fluorescence light is calculated in a large range of detunings around the barium (λ = 5535 Å) resonance transition. There is used the close-coupling theory of atomic collisions in the presence of weak radiation field [1] and the influence of the collisionaly induced spin-changing transition is examined. The calculations are based on the new theoretical potential curves for Ba atom interacting with rare gas atom obtained by means of a pseudopotential + valence configuration-interaction (CI) technique [2]. The profile and polarization has been calculated in two ways: taking into consideration and neglecting the spin-orbit mixing between the 1P and 3P states of isolated barium atom. This mixing becomes significant at the point at which the 1Π potential curve is crossed by the nore repulsive 3Σ one. The numerical results show that the influence of that mixing is important only in the red-wing part of spectra. This confirms the fact that for large red detuning, the absorption occurs predominantly to the 1Π state. The resonance scattering which becomes manifest in the calculations when the spin-orbit mixing is neglecting when annihilate by the 1Π - 3Σ crossing. The calculated absorption coefficients and polarizations have been thermally averaged over the collision energy for T = 800 K. Our theoretical results agree almost well with the recent experimental data [3].