Kinetics and spectroscopy of alkali rare-gas ionic excimers

Abstract

Many kinetic and spectroscopic studies were performed on alkali rare gas ionic excimer. The main results obtained during these investigations are presented. We observed fluorescence spectra from diatomic and triatomic molecules. Vacuum ultraviolet fluorescence emissions from alkali rare gas ionic excimer molecules were studied in detail by lowenergy electron beam excitation. Measurements were performed as a function of gas composition, gas pressure and deposited energy in order to investigate the kinetic mechanisms of these molecules. The rate constants of the formation and competitive reactions were determined from the observed fluorescence signal decay. Emissions of Ne-Xe-Cs mixtures excited by a pulsed electrical discharge were investigated experimentally as a function of gas pressure and gas composition. No fluorescence correlated to alkali rare gas molecules were observed. Triatomic ionic excimers have also been observed. These molecules have been produced by electron beam excitation. Emission spectra centered at -159nm due to Kr2Cs radiative decay were recorded. Binding energy of the lowest excited state is determined. Two formation channels for these triatomic ions are proposed and their rate coefficients estimated.Keywords: VUV, spectroscopy, kinetic, alkali, rare gas, electron beam, discharge ultraviolet fluorescence emissions from RgA molecules were studied in detail by lowenergy electron beam excitation. Emissions of Ne-Xe-Cs mixtures excited by a pulsed electrical discharge were also investigated experimentally and theoretically. Triatomic ionic excimers (Rg2A) have also been observed and studied. EXPERIMENTAL SETUPA detailed description of the experimental apparatus is given elsewhere'°. In this work only the main features of the set-up necessary for the interpretation of the experimental results are mentioned. The whole device consists of three main parts: The heated cell, the apparatus for the excitation of the gas mixtures in the cell and the optical detection system for spectral and time-resolved investigations on the emitted fluorescence spectra in the VIJV.'

Studies of Neutral and Ionic CuAr and CuKr van der Waals Complexes

“…The results from a series of ab initio calculations on CuAr/ CuKr may serve as comparison data for the performance of different functionals for such systems, because different density functionals have different performances for weakly interacting systems. For example, DFT methods based on Becke-type functionals 9,10 yield repulsive interactions for noble gas dimers, 11,12 whereas DFT methods based on the Perdew-type functionals 13 predict interaction energies for He 2 and Ne 2 that are several times too large. 14,15 The ab initio calculations also have intrinsic value, because little experimental information is available concerning these systems.…”

“…[1][2][3][4] Interactions between metal atoms and rare gas matrixes are common. These interactions can be significant and lead to the well-known matrix effect: a shift in the spectral features relative to the uncomplexed species.…”