MEASUREMENTS OF THE RADIATIVE LIFETIMES OF THE CL(2) ION-PAIR STATES BY OPTICAL OPTICAL DOUBLE-RESONANCE

The technique of optical-optical double resonance spectroscopy is used to study the radiative lifetimes of the Cl2 ion-pair states from the fluorescence decays. This experiment allows us to classify the six gerade states correlating to the lowest asymptote Cl-(1S) + Cl+(3P) into two groups from the fluorescence lifetimes. One involves the four spin-orbit components of the 3PI(g) state, 0g+(P-3(2)), 0g-(P-3(1)), 1g(P-3(2)), and 2g(P-3(2)), showing short lifetimes of 4-5 ns. The other includes those of 3SIGMA(g)- with lifetimes almost an order of magnitude longer; 44.6 +/- 0.5 ns for 0g+(P-3(0)) and 73.8 +/- 3.0 ns for 1. (P-3(1)).