engleski

Reverse Energy-Pooling In K-Na Mixture

We report experimental rate coefficients for the reverse heteronuclear energy-pooling collisions K(5D)+Na(3S)-->K(4P)+Na(3P) and K(7S)+Na(3S)-->K(4P)+Na(3P) at thermal energies. Both reactions are exothermic and very high rates were observed showing that reverse exothermic energy-pooling is an order of magnitude more efficient than the corresponding forward endothermic energy-pooling reactions. This is in accordance with the general behavior of the exothermic and endothermic energy-pooling rate coefficients in alkali-metal atoms. In the experiment the potassium atoms were excited in two steps to either the 5D or 7S state via the 4P level using two broadband cw dye lasers. A double-modulation technique has been used to select the fluorescence contributions at the Na(3P(J)) exit channels due only to the above reactions. The ground-state sodium and potassium atom densities were measured by the absorption of Lines from a K-Na hollow-cathode lamp. The measured densities and fluorescence intensities have been used to obtain absolute reverse energy-pooling rate coefficients. The contribution to the rate coefficients from other processes are discussed. [S1050-2947(98)03901-8].

energy pooling; cross section

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