Analysis of Dissociative Recombination of Electrons with ArXe + using ArXe* Calculations

Electron scattering from a molecular ion is closely connected with the behavior of the highly excited electronic states of the corresponding neutral molecule. Both systems are governed by the same Hamiltonian. This chapter reviews recent calculations that illustrate the methodology that can be applied in such situations. The examples described are drawn from our work over the past few years developing theoretical techniques to treat inelastic collision processes important in laser systems. For example, in the atomic xenon laser, the following processes are important: $$ Xe*\left( {n\ell KJ} \right) + He \to Xe*\left( {n\ell K'J'} \right) $$ (1) $$ Xe*\left( {n\ell KJ} \right) + Ar \to Xe*\left( {n\ell K'J'} \right) $$ (2) $$ ArXe + e \to Xe*\left( {n\ell K'J'} \right) + Ar $$ (3) Processes (1) and (2) are fine structure changing collisions. The quantum numbers specify the atomic orbital (nl), the details of the angular momentum coupling between the valence electron and the ionic core (K), and the total angular momentum (J). We have recently calculated the excited state potential curves and matrix elements necessary for a quantum mechanical treatment of the dynamics of these collisions.1,2 Process (3), dissociative recombination (DR), involves the same atomic particles (in a different arrangement) as processes (1) and (2). Using information from our recent calculations on the low-lying excited states that govern processes (1) and (2), we have been able to obtain the necessary potential curves and matrix elements to analyze DR.