The use of rotating magnetic fields (RMF) to drive steady currents in plasmas involves a transfer of energy and angular momentum from the radio frequency source feeding the rotating field coils to the plasma. The. power-torque relationships in RMF systems are discussed and the analogy between RMF current drive and the polyphase induction motor is explained. The general relationship between the energy and angular momentum transfer is utilized to calculate the efficiency of the RMF plasma current drive. It is found that relatively high efficiencies can be achieved in RMF current drive because of the low phase velocity and small slip between the rotating field and the electron fluid.
Magnetic particles confined in microchannels can be actuated to perform translation motion using a rotating magnetic field, but their actuation in such a situation is not yet well understood. Here,...
Rotating magnetic fields (RMF) have been used successfuly to drive steady currents in plasmas in many experiments. Some recent experimental and theoretical results did not seem to agree with the standard model based on assuming that the electrons are 'tied' to the lines of the RMF. A more general model based on the concept of flux preserving motion is developed in this paper. It appears that this model provides a unified approach for predicting the qualitative features of RMF current drive under a variety of conditions.
Power and Momentum Relations in Rotating Magnetic Field Current Drive
