Xenon luminescence in high pressure argon: spectroscopy and kinetics

Abstract

The luminescence associated with selective excitation of the three lowest xenon resonant levels ( 3P 1/6s[ 3 2 ] 0 1, 1P 1/6s′[ 1 2 ] 1 and 5d[ 3 2 ] 0 1) in high pressure (14–71 bar) argon doped with minimal amount of xenon is reported. Under these conditions the decay channels specific to Xe*Ar were obtained without Xe* 2 formation. In particular, it is demonstrated that the part of the 3P 1 level excitation population which is not radiated “immediately” is first transferred to the 3P 2 metastable level. Subsequently a long 3P 1 decay also occurs via its formation by the reverse reaction. An analogous behavior is found for the upper 1P 1/ 3P 0 levels showing that most of the fluorescence is retarded with in this case transfers of population to the close 6p[ 1 2 ] 1 and to 6s( 3P 1/ 3P 2) levels. The behavior found after 5d[ 3 2 ] 1 level excitation is quite diferent, with in parallel a fast direct fluorescence and a quenching into the 1P 1/ 3P 0 levels but not directly into the 3P 1/ 3P 2 levels. A kinetic analysis is developed according to these schemes. Particularly, the 3P 1 to 3P 2 quenching is found to depend linearly on the density with the rate k 2=(4.5±0.5) × 10 −13 cm 3 s −1. The more complicated description of the 1P 1 clearly indicates the necessity of using selective excitation to succeed in a self-consistent interpretation.