Plasma response to externally applied resonant magnetic perturbations

Abstract

Based on recent finding that applied resonant magnetic perturbation (RMP) can either increase or decrease the local electron density gradient around the resonant surface (Yu and Günter 2009 Nucl. Fusion 49 062001 ), the plasma response to the RMP of a single helicity is studied numerically by further taking into account the electron energy transport. It is found that the changes in the local electron density and temperature by RMPs are coupled. If the local parallel heat diffusivity and/or the island width are sufficiently large, the local electron temperature profile flattens, which enhances the change in the local electron density gradient. Depending on the plasma parameters, either the plasma rotation frequency or the electron diamagnetic frequency (electron pressure gradient) can be significantly changed by RMPs, and these two changes affect each other. With a reduced set of equations that does not include the electron energy transport equation, the particle transport in stochastic magnetic fields is found to be similar to that across a single magnetic island.