ELECTRONIC-STRUCTURE OF THE NOBLE-GAS DIMER IONS .2. THEORETICAL ABSORPTION-SPECTRUM FOR THE A2-SIGMA+1/2U-]D2-SIGMA+1/2G SYSTEM

A systematic study of the UV photoabsorption characteristics of the dimer ion sequence Ne2+, Ar2+, Kr 2+, and Xe2+ has been carried out. Spin-orbit coupling effects, which become progressively more important in the sequence Ne2+→Xe2+, result in a mixing of the strong Σ-Σ and weak Σ-Π electronic transition moments. By combining these calculated transition moments with the potential energy curves given in paper I, an analysis of the bound-free absorption spectra of these ions has been carried out for the strong component of the transition moments. Detailed calculations of the photodissociation cross sections corresponding to the A 2Σ1/2u +→D2Σ1/2g+ system of these ions are presented as a function of individual ion vibrational levels and as a Boltzmann average for temperatures of 150, 300, and 600°C. The importance of strong UV absorption by noble gas dimer ions in analyzing photon loss processes in excimer laser systems is discussed. © 1979 American Institute of Physics.