International Workshop on Atomic Interactions in Laser Fields - Abstracts
F. Rebentrost
Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany
We review the quantum, coupled-channels theory of optical collisions. For atomic systems like the alkali/rare-gas systems
Na(32S1/2) + Kr + hν → Na(32Pl/2,3/2) + Kr
a quantitative description is achieved for optical collisions under thermal conditions as well as for the more recent applications to experiments with differential detection in a molecular beam [l, 2]. Some of the most apparent features of the differential cross sections like the pronounced oscillatory structure due to interference of different Condon pathes are well reproduced also by semi-classical theory. A classical picture often applies to understand the geometry of the collision complex (Condon vectors) at the instant of excitation. We have investigated in detail the nonadiabatic couplings in the collision complex due to the spin-orbit interactions. It was found that the heavier Na-RG systems are well characterized by a universal nonadiabatic coupling function p(2BΣ → 2P1/2) allowing a direct comparison of data from molecular beam and cell experiment with calculation.
Nonadiabatic effects due to radial and angular couplings play a.n important role to understand transitions into the Li(3P) state occuring in optical collisions in the LiNe 2P→3D system [3]. We discuss results using the new potentials and coupling matrix elements obtained by Jungen et al..
The photodissociation of homonuclear ions H2+, Ar2+ in strong laser fields is governed by the subbarrier tunneling, free passage and stabilization regimes in the light-induced adiabatic molecule+field potentials. The most evident manifestation of the stabilization effect is the occurence of new bound levels in the upper adiabatic potential. There is however no clear experimental demonstration so far. We discuss its verification on the basis of wave-packet calculations employing short-pulse excitation and new experimental efforts.