The density-matrix formalism for description of step-wise laser-excitations of atoms and molecules in high-collisional media

Ove Axner, Peter Ljungberg

Peter Ljungberg, Denis Boudreau, Ove Axner

Soo Chang, Vladimir G. Minogin

Man Mohan, Vinod Prasad

W -K Liu, A S Dickinson

The inelastic lineshape expression for two-step sub-Doppler excitation of a four-level atomic or molecular system in the presence of a low-pressure perturber is derived by treating the collisional effects to first order. The degeneracies of the rotational levels and the tensorial coupling due to the laser fields and collisions have been fully taken into account by working with the irreducible tensorial components of the density matrix. Explicit expressions for the collision cross sections affecting the lineshape are derived using the Liouville-space formalism.

Sergey V. Ambrosov

It is proposed and studied a new optimal theoretical scheme for the laser photoionization sensor of the separating isotopes, nuclear isomers and nuclear reactions products, which is based on the selective laser excitation of the isotope atoms into excited Rydberg states and further stochastic collisional ionization mechanism. The operator perturbation theory and FockerPlank stochastic equation method are used for description of stochastic collisional ionization process. The optimal laser action model and density matrices formalism is used for numeric calculation of the optimal scheme of the Na, U, Cs and Cf isotopes (ions, nuclei) sensing.