EXCITED STATE KINETICS IN HIGH PRESSURE GAS MIXTURES OF KRYPTON AND CHLORINE AND IN KRYPTON AND XENON
DURRETT, MICHAEL GREGORY
Doctor of Philosophy
Formation and decay of KrCl/Kr(,2)Cl and (KrXe) + excited states have been studied by following the time dependence of the various fluorescence bands. For the KrCl/Kr(,2)Cl system the time dependence of the fluorescence from KrCl (B), KrCl(C), and Kr(,2)Cl was measured following pulsed 135 nm excitation of chlorine. The Cl* is found to react very rapidly with krypton to form KrCl in a vibrationally excited state. Above (TURN)75 torr the formation of the radiating states is found to be rate limited by vibrational relaxation (K(,vib) = 8.6(+OR-), 4 x k9('-11)). Following vibrational relaxation the B and C states are completely mixed and decay with a mixed state radiative lifetime of 5.4 (+OR-) .1 ns. The mixed state is strongly quenched by chlorine (K = 7.6 (+OR-) 5 x 10('-10)) and also by krypton in a three body process (K = 1.15 (+OR-) .03 x 10('-30)) which presumably leads to production of Kr(,2)Cl. However, the measured formation rate of Kr(,2)Cl is much slower than the three body quenching of KrCl is much slower than the three body quenching of KrCl and an intermediate ions lived state of Kr(,2)Cl is suggested. The Kr(,2)Cl emission, monitored at 325 nm, is strongly quenched by chlorine (K = 6.7 x 10('-10)) but only weakly, if at all, by drypton (K (') 1 (mu)sec). The time dependence of 4900 A emission in Kr-Xe mixtures was also measured following pulsed excitation by a low intensity high energy electron beam. The time dependence was obtained at pressures of 500 to 10000 torr and at temperatures ranging from 30 to 40 des C. The population of the upper ionic state of the transition is found to be governed by a dissociation recombination reaction which establishes an equilibrium between the heteronuclear molecular ion and its associated atomic ion. The measured dissociation and recombination rate constant for this reaction are 1.94 (+OR-) 12 x 10('-11) and 5 (+OR-) 2 x 10('-32) respectively. The radiative lifetime was determined to be (46 (+OR-) 4 ns). The temperature dependence of the dissocation rate constant yields an activation energy of 0.08 (+OR-) .02 ev.