Small aspect ratio tokamak configurations are produced by adding a toroidal magnetic field to the rotamak. Configurations with toroidal fields ranging up to ∼ 200 G at the magnetic axis are studied. Typical parameters are Itor ∼ 2 kA, Bpoi ∼ 50 G, q0 ∼ 1-3, ne (peak) ∼ 1019 m−3, Te ∼ 12 eV, τp ∼ 15 μs and τe ∼ 5μs for an RF input power of ∼ 40 kW. Most features of these configurations can be modelled by an MHD equilibrium code. The presence of the toroidal field is observed to have a significant influence on the rotating magnetic field current drive mechanism.
Predictions of toroidal rotation and torque sources arising in non-axisymmetric perturbed magnetic fields in tokamaks