Start-up of HF plasma discharge in the Uragan-3 torsatron

Wave processes at the initial stage of plasma creation by HF method in torsatron ''Uragan-3'', are experimentally studied. Amplitude and frequency characteristics of excited HF fields in plasma at the stage of plasma creation and the yield of its density at the stationary level, are determined. The optimum conditions for HF charge formation in the value of operating gas pressure and voltage applied to antenna HF device are determined. It is shown that the spectrum in the longitudinal lengths of λparallel waves of electromagnetic oscillations excited in plasma is determined by spectral characteristics of the external antenna device. Electrostatic HF oscillations conditioned by the development of parametric instabilities of low-density plasma at the electrostatic branch of Alfven waves are found at the initial stage of plasma formation