MHD Activity by HIBD

This seminar talk summarizes the results of an experimental investigation of the plasma potential in toroidal magnetic fusion devices. It presents data obtained with the unique heavy ion beam probing (HIBP) and other diagnostics. Diagnostic systems to probe the T-10 tokamak and the TJ-II stellarator plasmas are described. They allow ones to measure the steady-state plasma potential profiles and the potential’s oscillations, such as quasi-monochromatic and broadband fluctuations. The findings in the turbulent particle transport, plasma density fluctuations, and poloidal magnetic field studies are reported as well. The properties of Geodesic Acoustic Modes and Alfven eigenmodes, driven by fast particles during a neutral beam injection heating of plasma, are discussed. A wide range of plasma scenarios in tokamaks and stellarators with various magnetic configurations and plasma heating systems are reported, and common features in the behavior of the plasma potential and turbulence in magnetized plasmas are shown.