Secondary flow due to Alfven waves

The paper discusses secondary motions that could disrupt primary Alfven waves. Large (gigajoule) amounts of energy can in principle be stored as kinetic energy in liquid metal circulating round a torus and can be extracted at the gigawatt level by Alfven waves propagating along an imposed axial field. However a major limitation on this energy is the disruption of these primary Alfven waves by secondary flows in meridional planes, associated with out-of-balance centrifugal forces ahead of and behind the waves and nonuniform magnetic pressures at the wave fronts. Vorticity, created at the wave, itself propagates in secondary Alfven waves. A linearized treatment of these secondary motions and the associated perturbations of the imposed axial field is given comparing the resulting disruption of the primary wave mode with crude estimates made earlier. The problem may be of interest in MHD.