Drifts and plasma losses in Q devices with curved magnetic fields: Calculations

The conditions of toroidal equilibrium prevailing in a Q device with curved magnetic lines have been analyzed from the two-fluid equations. The density profiles are calculated to second order in an expansion in reciprocal powers of the radius of curvature. The main features of the equilibrium are toroidal and E × B drifts that, to first order, give rise to shifts of the plasma column and, to second order, to plasma losses. These calculations can account for the experimental observations without invoking low-frequency "drift" waves on confinement.