Study of turbulence spectra in a spherical tokamak plasma

Abstract

A turbulence study was carried out on the Globus-M tokamak. The main method of turbulence studying was Doppler backscattering. Studies have been performed at different radii (in areas with different plasma parameters). It was found that during the transition from H-mode with edge localized modes (ELMs) to the improved confinement mode without ELMs, both turbulent fluctuations of the plasma density and velocity fluctuations are suppressed, which apparently leads to a decrease in anomalous transport.