The Effect of Biasing on the Radial Profile of Electrical Fluctuations in IR-T1 Tokamak

Abstract

In this experiment, the biasing effect on the control of turbulence in IR-T1 tokamak was investigated. The radial profile of the average density, the relative level of fluctuations and their power spectrum were obtained in the presence of biasing with two positive and negative polarities by using an array of Langmuir probe (Rake probe). Biasing was more effective in reducing the fluctuations at the edge of the plasma than in the more internal regions, but the spectral power of fluctuations in the inner regions decreased faster. Striking issue is that the positive bias has been more effective than negative bias in increasing of confinement.