EXCITATION OF VACUUM UV TRANSITIONS OF ALKALI-METAL ATOMS BY CHARGE-EXCHANGE REACTIONS

We investigate the vacuum UV radiation spectra of atoms and ions of Rb, Cs, He, Ne, and Ar in a discharge plasma of their mixtures at different concentration of metal vapors in rare gases. The reactions leading to population and deactivation of resonant states of rare-gas atoms were studied. The observation of lines 109.1, 119.6, and 124.7 nm, corresponding to the radiation transitions from the 5p(5)5d6s(4)P(5/2) quasi-metastable autoionizing level of cesium, allowed us to estimate experimentally the cross section sigma = (9 +/- 3). 10(-15)cm(2) of the charge-exchange reaction of the metastable cesium ion on the cesium atom, giving as a result the above-mentioned quasi-metastable state of cesium.