Reverse energy pooling in a K-Na mixture
- Niels Bohr Institute, O/rsted Laboratory, Universitetsparken 5, DK-2100 Copenhagen O/ (Denmark)
- Istituto Nazionale per la Fisica della Materia, Dipartimento di Fisica, Universita di Pisa, Piazza Torricelli 2, I-56126, Pisa (Italy)
We report experimental rate coefficients for the reverse heteronuclear energy-pooling collisions K(5D)+Na(3S){r_arrow}K(4P)+Na(3P) and K(7S)+Na(3S){r_arrow}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{sub 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. {copyright} {ital 1998} {ital The American Physical Society}
- OSTI ID:
- 565838
- Journal Information:
- Physical Review A, Vol. 57, Issue 1; Other Information: PBD: Jan 1998
- Country of Publication:
- United States
- Language:
- English
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