STUDY OF NONRESONANT CHARGE-EXCHANGE PROCESSES IN NE-CS AND HE-RB MIXTURES

The population decay of resonantly excited levels of Rb+ ions (5s[1/2] (1) and 4a(3)P(1)), Cs+ ions (5d[1/2](1), 6s[3/2](1), and 6s[1/2](1)), and of He(2(1)P(1)) and Ne(3s(1)P(1)) atoms is studied by their VUV e mission spectra in decaying plasmas of Ne-Cs and He-Rb mixtures. The r ates of conversion of neon and helium atomic ions into molecular ions via three-body collisions in the Ne-Cs and He-Rb mixtures are obtained : k(Ne) = (0.62 +/- 0.2) x 10(-31) cm(6)/s and k(He) = (3.18 +/- 0.8) x 10(-31) cm(6)/s. The role of the nonresonant charge exchange in thes e mixtures is analyzed. The overall rate constant of the charge exchan ge in the He-Rb mixture, delta = (3.88 +/- 0.9) x 10(-10) cm(3)/s, is obtained, as well as the overall rate constant of the excitation trans fer from the near-lying metastable states to the resonantly excited le vels of cesium ions in the Ne-Cs mixture, involving low-velocity elect rons: alpha(e) = (4.9 +/- 1.6) x 10(-7) cm(3)/s, and the rate constant of radiative recombination of Cs2+ ion: alpha(e)(++) = (1.45 +/- 0.3) x 10(-8) cm(3)/s.