Decay rates of Ar(4<i>s</i>,3<i>P</i>2), Ar(4<i>s</i>′,3<i>P</i>), Kr(5<i>s</i>,3<i>P</i>2), and Xe(6<i>s</i>,3<i>P</i>2) atoms in argon

Abstract

The decay rates of Ar(3P2), Ar(3P0), Kr(3P2), and Xe(3P2) metastable states in argon carrier gas have been measured in a flowing afterglow apparatus. From analysis of the dependence of the pseudo-first-order decay constants upon pressure, the diffusion, two-body, and three-body rate constants have been assigned for each metastable state in Ar. The rate constants found for Ar(3P2) agree with the values accepted in the literature for these processes. The two-body rate constants for Kr(3P2) and Xe(3P2) are a factor of 4 lower than for Ar(3P2). The three-body rate constants for Kr(3P2) and Xe(3P2) are reduced by factors of 10 and 100, respectively, relative to the Ar(3P2) rate constant. The reduction in three-body constants for Kr(3P2)+2Ar and Xe(3P2)+2Ar is consistent with the reduced binding energy of KrAr* and XeAr*. The diffusion and three-body coefficients for Ar(3P0) are equal to those for Ar(3P2), but the two-body rate constant is 2.5 times larger than for Ar(3P2). The results for each of the three processes are discussed in terms of physical models.