Effects of radial transport on current drive in tokamaks

Abstract
The influence of radial transport of electrons on radiofrequency and Ohmic current drive in tokamaks is discussed. It is found that such processes can reduce the efficiency of current drive in tokamaks in which the energy confinement time is comparable with or less than the collision time of the heated electrons and that, even if this is not the case, they significantly broaden the driven current profile.