V-E ENERGY-TRANSFER IN ETHYLENE AND ALKALI GAS-MIXTURES USING INFRARED MULTIPHOTON EXCITATION

V-E energy transfer in C2H4 and alkali gas system C2H4double dagger+M- ->C2H4+M(M=Na, K, Rb, and Cs, double dagger denotes high vibrationall y excited state, denotes electronically excited state) was investiga ted by using IR multiphoton excitation of C2H4 and probing the atomic fluorescence due to the above process. The atomic decay rates were det ermined as a function of alkali or ethylene gas concentration. The rat e constants of V-E energy transfer were originally obtained by compari ng the decay rate under different experimental conditions with the sol ution of the set of equations based on a proposed kinetic model. The k inetic information with respect to the inverse E-V energy transfer and the deexcitation process of the highly vibrationally excited state C2 H4double dagger were also obtained which agreed well with the results obtained from other methods. The large cross sections of the V-E energ y transfer and their weak dependence on temperature obtained were inte rpreted based on a harpooning mechanism.