Radiofrequency ionization of helium with turbulent flow-measurements versus theory

Summary form only given, as follows. Computations have been made for two sets of conditions of RF discharge tests with helium flow investigated by M.E. Talaat (J. de Physique., Coll.C7, Suppl. No.7, vol.40, p.C7-165, 1979). The computation of the plasma column voltage V/sub p/ versus the current I were simplified by assuming a radial distribution of the electron particle density n. This is because the dominant plasma processes were found to be made up of (a) a two-step ionization process consisting of collisional excitations of the ground state atoms by the tail electrons, followed by collisional ionization of the metastable state atoms by the bulk electrons, (b) a two body radiative and neutral assisted recombination process of the dominant molecular positive ions to atomic or molecular metastables, and (c) a diffusion process which is primarily dependent on the turbulent diffusion coefficient. The measured applied voltage, the computed V/sub p/, and the derived equivalent capacitive reactance voltage drop are plotted versus I for two sets of test conditions.<>