Drift-Wave Turbulence Effects on Magnetic Structure and Plasma Transport in Tokamaks

Abstract

The small magnetic perturbations accompanying drift waves are shown to produce microscopic, fluctuating magnetic island structures and to enhance radial electron heat transport in tokamaks. The "magnetic-flutter"-induced electron heat-conduction coefficient is found to be ${{\ensuremath{\chi}}_{e}}^{\ensuremath{\delta}}\ensuremath{\simeq}\frac{3}{16} (\ensuremath{\nu}+\ensuremath{\gamma}){\ensuremath{\delta}}^{2}$, where $\ensuremath{\delta}$ is the magnetic island width, $\ensuremath{\nu}$ is the electron-ion collision frequency, and $\ensuremath{\gamma}$ is the drift-wave growth rate, or inverse island correlation time.