THE MECHANISM OF THE ARGON EMISSION CONTINUUM IN THE VACUUM ULTRAVIOLET. I

Abstract

The spectral intensity, Iem, of the microwave excited continuous emission in molecular argon has been investigated from 1 060 to 1 450 Å as a function of pressure (pAr) with the result:[Formula: see text]The Ar2 continuum, like Xe2, Kr2, and Ne2 (X2), exhibits a sharp short wavelength limit corresponding energetically to the 3p54s3P0 resonance configuration and two intensity maxima at 1 080 and 1 265 Å. The integrated intensities of the rare-gas continua compare as follows:[Formula: see text]with (Iem)Ne expected to be weaker still. The pressure dependence and the short wavelength limit suggest a two-body collision process involving 3P0 atoms as the controlling step to produce [Formula: see text] molecules responsible for the continuum.Although the lifetimes of the 3P0 atoms do play a kinetic role in the continuum production, it is concluded that the molecular transition probabilities, [Formula: see text] predominate and decrease, as expected in the direction Xe2* to Ne2* in the approach (weaker spin-orbit coupling) to Hund's case b.