Pressure effects on kinetics and decay processes in krypton after selective photoexcitation

• Published in: The Journal of chemical physics 1988-11, Vol.89 (10), p.6176-6188
• Main Authors: AUDOUARD, E, LAPORTE, P, SUBTIL, J.-L, DAMANY, N
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Atomic properties and interactions with photons; Exact sciences and technology; Fluorescence, phosphorescence (including quenching); Physics
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.455434

Kinetics associated with the decay of the 5s[3/2]01 (3P1) excited state of krypton is investigated using selective excitation, in the density range 2.5×1018 to 375×1018 atoms cm−3 (pressure from 104 to 1.5×106 Pa). The vacuum ultraviolet (VUV) one-photon excitation around 123.6 nm is provided by monochromatized light from a laser-generated rare gas plasma. The basic experimental data are obtained through the time-resolved second continuum excimer fluorescence at 145 nm. When initial conditions give purely 3P1 atomic excitation a single slow component is observed at densities up to 15×1018 cm−3, corresponding to the 1u,0−u, v=0 excimer radiative decay (265 ns). From 15 to 60×1018 cm−3, a second fast component shows up, corresponding to the 0+u(3P1), v=0 excimer radiative decay. Above 60×1018 cm−3 the intensity ratio between the two components remains constant (F/S≊0.21). Behavior rather similar to that previously reported for argon and xenon is found. In particular one concludes that the 3P2 atomic state plays a major role as an intermediate state in the 1u,0−u dimer formation whereas possible short-distance attractive g states do not seem to play any significant role. A self-consistent analysis leads to a detailed quantitative description of the kinetics. In particular, it is found that dimer formation times from 3P1 and 3P2 atomic states are in the ratio 3/1. In the considered density range collisional rates are found to vary quadratically.