Magnetic island deformation due to sheared flow and viscosity

A partial differential equation for a two-dimensional magnetohydrodynamic ( MHD) equilibrium with flow and viscosity is derived. The equation is used t o describe the deformation of the magnetic island caused by the viscous dra g of a sheared flow. The deformation is characterized by the phase gradient of the magnetic perturbation across a magnetic island. This phase gradient has been observed experimentally in electron cyclotron emission data from the DIII-D tokamak [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (19 85)]. (C) 1999 American Institute of Physics. [S1070-664X(99)02904-3].