Tanks-Dattner resonances and their application in plasma diagnostic

Tonks-Dattner resonances in a plasma column were studied for neutral gas densities and frequencies from about 1013 to 1015 cm-3 and 3.9 to 4.4 GHz respectively. The dipole resonance appeared at electron densities predicted by cold plasma theory. A parabolic model for the electron density profile yielded consistent results over the entire neutral density range. Going from the lowest to the highest neutral gas densities the electron thermal energy varied from about 12 to 3 eV. The electro-acoustic standing waves occupied an increasingly larger distance between wall and profile as the electron thermal velocity increased. (Auth.)