Electronic‐energy exchange cross sections for Ar* (3P) and Kr(1S)

Differential cross sections for Ar* scattered by Kr are obtained at four relative kinetic energies, 60.6–156 meV. Location and shape of rainbow maxima, observed at all the energies, are used to determine parameters for a double‐Lennard‐Jones potential. The parameters, e=9.11±0.25 meV and rm=5.06±0.84 A, are the same as those for K+Kr and are substantially different from those of Ar+Kr. A second set of maxima, visible at all energies and caused by exchange of electronic energy from Ar* to Kr, are analyzed to determine electronic‐energy exchange cross sections. The cross sections together with those obtained from thermal‐energy quenching measurements are consistent with an increase from a threshold of 25 meV. Possible mechanisms for the electronic‐energy exchange are discussed.

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