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

Time‐resolved nsec kinetic methods are used to measure state specific electronic excitation transfer for the near‐resonant process: Ca(4s5p ¹P₁) +Ar $\underset{k_{\text{-1}}}{\overset{k_1}{\rightleftarrows }}$ Ca(4s5p ³P_2,1,0)+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.