Measurements of the Radial Distributions of the Geodesic Acoustic Mode and Quasi-Coherent Mode Using a Heavy Ion Beam Probe in the T-10 Tokamak Ohmic Plasma

Radial distributions of the electric potential and plasma density oscillations have been measured in the T-10 tokamak ohmic plasma. Radial distributions of the amplitude and frequency of the geodesic acoustic mode are plotted according to the data on the fluctuations of the electric potential of the plasma, and radial distributions of the amplitude and frequency of the quasi-coherent mode are plotted according to the data on the fluctuations of the plasma density. The quasi-coherent mode corresponds to the major part of the turbulent particle flow, the geodesic acoustic mode as a high-frequency branch of zonal flows is involved in the turbulence regulation, which makes these objects very important for plasma physics. The paper presents the results obtained in different operating modes of the T-10 tokamak.