Dispersion studies of surface-wave-produced discharges with view to diagnostics

Dispersion of surface-wave produced plasmas and field behaviour right outside the discharges are studied under the influence of collisions, radial and axial density inhomogeneities, the latter one both in WKB and eigenfunction treatment. The trends of joint influences can be approximated by an extrapolation from WKB treatment, avoiding the large numerical effort of an-accurate-two-dimensional code. Some consequences for radiophysics diagnostics are pointed out. Whereas standard methods of phase measurements are only weakly affected, amplitude measurements are more subjected to various influences. Therefore, potential extensions of methods using test waves of various frequencies can yield additional and improved informations on collision frequency and on the value of the radial inhomogeneity index. A procedure is suggested and exemplified with measurements at a helium discharge. (orig.)SIGLEAvailable from TIB Hannover: RO 9159(76)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman