PLASMA TRANSPORT NEAR THE SEPARATRIX OF A MAGNETIC ISLAND

The simplest nontrivial model of transport across a magnetic island ch ain in the presence of collisionless streaming along the magnetic fiel d is solved by a Wiener-Hopf procedure. The solution found is valid pr ovided the boundary layer about the island separatrix is narrow compar ed to the island width. The result demonstrates that when this assumpt ion is satisfied the flattened profile region is reduced by the bounda ry layer width. The calculation is similar to the recent work by Fitzp atrick [Phys. Plasmas 2, 825 (1995)] but is carried out in the collisi onless, rather than the collisional, limit of parallel transport, and determines the plasma parameters on the separatrix self-consistently. (C) 1997 American Institute of Physics.