Improvement of radial confinement of plasma via applying rotating magnetic fields

Abstract

Abstract We report a novel method to control the plasma radial transport, namely, applying a rotating magnetic field (RMF) to create azimuthal shear flow, which is found to change the transport from Bohm to classical diffusion if the ratio of magnetization parameter γ to penetration parameter λ is greater than 1.5. Upon application of the RMF, the peak density is observed to increase by 33% above the normal value. Specifically, the ratio increases from 4 × 1018 m−3 to 6 × 1018 m−3, and the corresponding density gradient length changes from 11 cm to 6 cm, or the steepness increases by about a factor of 2. Further increasing the RMF strength cannot steepen the density further. The results suggest the RMF can be a non-intrusive method to control the radial transport and hence the plasma density profile.