PLASMA CONVECTION INDUCED BY TOROIDAL ASYMMETRIES OF THE DIVERTOR PLATES AND GAS PUFFING

摘要

In the open field line region of the scrape-off layer (SOL), the plasma potential is to a considerable degree determined by the boundary conditions on the divertor plates. The idea is explored here that, by making the divertor plates slightly 'wavy' in the toroidal direction, toroidally varying potentials can be produced throughout the SOL and thereby convective plasma motion induced. This motion should lead to a broadening of the SOL and to a reduction of the heat load on the divertor plates. An attractive feature of this technique is that it induces strong convection only on the open field lines without causing enhanced transport inside the separatrix.