Fluctuation-induced dynamo effect in a magnetic confinement plasma

Abstract

The electron temperature fluctuation-induced dynamo electric field has been measured in the core of high-temperature EAST tokamak plasmas by Faraday-effect polarimetry and electron cyclotron emission. It is found that a dynamo electric field primarily arises from the coherent interaction between radial magnetic-field fluctuations and electron temperature fluctuations associated with the internal kink instability, acting to self-regulate the current profile to prevent sawtooth magnetic reconnection.