Investigation of Poloidal Phase Velocity of Floating Potential Fluctuations in the IR-T1 Tokamak Edge Plasma

Tow pairs of poloidally spaced and radially movable Langmuir probes were used for measuring ion saturation current and floating potential in the edge plasma of IR-T1 Tokamak. Radial profile of the floating potential, it’s gradient, that is proportional to radial electric field Er ,and phase velocity of plasma fluctuations are determined. Results show that there is a naturally occurred velocity shear layer in the proximity of the last closed flux surface.