The radiative decay of metastable 1s22s22p41S0atomic oxygen atoms has been shown to proceed at a rate depending linearly on the concentration of argon or xenon present in the gas mixture. With increasing pressure, the1D2sngbnd;1S0atomic line at 5577 Aring; becomes accompanied by a broad emission region identified as a band system of a weakly bound rarehyphen;gas oxide molecule. Changes in the transition probability as a function of pressure were measured by using the spinhyphen;forbidden3P1sngbnd;1S0transition at 2972 Aring; as a pressurehyphen;independent monitor of the O(1S) concentration. The observed pressure dependence of the emission probability may be described by rate constants for induced emission in argon and xenon atmospheres: (1) for emission in a bandwidth of plusmn;1.6 Aring; centered on the atomic line at 5577 Aring;,k(Ar)equals;(7plusmn;3)times;10minus;20cm3secminus;1,k(Xe)equals;(3plusmn;2)times;10minus;19cm3secminus;1; and (2) for emission into the entire green band system,k(Ar)equals;(3.0plusmn;.2)times;10minus;18cm3secminus;1,k(Xe)equals;(1.7plusmn;.2)times;10minus;15cm3secminus;1. Comparison is made with rate constants for deactivation of these metastable atoms by the same rare gases. It appears that substantially all of the collisionhyphen;induced emission comes from bound rarehyphen;gas oxide molecules whose dissociation equilibria provide the observed pressure dependence.
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