Laser studies of electronic excitation transfer in atomic calcium:  Ca(4s5p 1P1)+Ar⇄Ca(4s5p 3P2, 1, 0)+Ar

Abstract

Time-resolved nsec kinetic methods are used to measure state specific electronic excitation transfer for the near-resonant process: Ca(4s5p 1P1) +Ar ⇄k-1k1 Ca(4s5p 3P2,1,0)+Ar. In stimulated emission experiments it is found that the Ca(4s5p 3P2) level is preferentially populated. The rate constant k1 for the specific 3P2 channel is 5.2±0.5×10−11 cm3 molecule−1 sec−1. These results are discussed in terms of near-resonant spin changing collision mechanisms. Radiative lifetimes for Ca(4s5p 1P1) and Ca(4s5p 3P1) are also determined to be 77±2 nsec and 67±2 nsec, respectively.

Impact of buffer gas quenching on the 1S0 → 1P1 ground-state atomic transition in nobelium

“…The quenching of atomic levels in a gas environment is reported in similar systems, e.g. in atomic barium [19] and calcium [20]. From the laser pulse duration of about 18 ns in our experiment, a lower limit on the de-excitation rate can be estimated to be of the order of 10 8 s −1 , which is much larger than values in noble gases for energy gaps of the order of 1000 cm −1 .…”

Collisional dynamics of low energy states of atomic strontium following the generation of Sr(5s5p1P1) in the presence of He and Ar

“…18 On the other hand, Sr(5 3 P 0,1,2 ) is considered kinetically as three separate states including the role of the '' reservoir '' states, 3 P 2 and 3 P 0 , as described in earlier collisional studies on this isolated manifold. 13,18 We may also mention here the fluorescence study initiated using the second (4s5p 1 P 1 ) excited state of Ca by Leone et al 19,20 A discussion of the modelling method accompanying the experimental measurements used for extracting kinetic information from the raw data, beginning with simplifying kinetic approximations which are then subsequently refined, together with sensitivity analyses of the fittings, is presented in detail.…”