Excimer emission spectra of rare gas mixtures using either a supersonic expansion or a heavy-ion-beam excitation

Abstract

Results related to the energy transfer in the rare gas mixtures are reported for an electrical discharge excitation with plasma expansion and a heavy-ion-beam excitation. Energy transfer from the lighter rare gases to the heavier ones was observed in a very efficient way for both excitation mechanisms. Strong emission from excited atomic states, which are possible candidates for new lasers, was observed for the electrical discharge case. The broad-band emission of the discharge sources makes them appropriate for strong lamps in the VUV. Some comparisons of the two excitation mechanisms were discussed with respect to the energy deposition, the density of dimers and their vibrational relaxation.

Ion-beam excitation of liquid argon

“…As a result, all spectra recorded within the scope of this work show a very weak emission line stemming from xenon at 148.9 nm [8,9]. From a comparison of the emission spectra in the gas phase to argon spectra where quantitatively defined traces of xenon were deliberately added [47] the remaining xenon concentration in our gas could be estimated to be much smaller than 3 ppm; a comparison in the liquid phase to spectra recorded with electron beam excitation [7][8][9] yielded a xenon impurity of even less than 0.3 ppm. The beam current of the MLL ion beam sometimes showed some instabilities.…”

“…In the gas phase this width is found to decrease with decreasing temperature [7,[45][46][47][48]. The energy level of the singlet lies thereby slightly higher by ∼75 meV [46] than the energy level of the triplet state, however, due to the width of the second excimer continuum the two transitions cannot be resolved spectroscopically.…”

“…4), which could be related to a different local heating. In the gas phase the width is known to be influenced by temperature [7,[45][46][47][48].…”

Electron beam induced light emission

“…A mixture of argon and nitrogen shows an enhanced emission on the C-B band of nitrogen between 300 and 400 nm. Mixtures of rare gases show energy transfer from the light to the heavier rare gas with emission due to the formation of mixed molecules [11] and for higher concentrations of the heavier species on the rare gas excimer band of these heavier species (first and second continuum) [12].…”

Potential energy curves and dipole transition moments for excited electronic states of XeKr and ArNe

“…[1][2][3] While most experimental and theoretical work has been devoted to homonuclear systems, the heteronuclear systems have also attracted interest following the observation of very efficient energy transfer processes in admixtures of rare gases, 1,4 -6 and this opens new possibilities for the efficient pumping of these systems. 7 The advent of experimental studies of thermal energy collisions between excited and ground-state raregas atoms 8,9 offers a challenge to theoreticians to provide interpretations of the resulting experimental data. Accurate potential energy curves are required for the interacting pairs of atoms over a large range of interatomic distances.…”