MHD-driven internal coils for tokamak divertor operation

In this paper a system evaluation of MHD coils for divertor coil and as passive stabilizer against plasma vertical displacements is presented. The advantages of placing the poloidal field coils are quantified. Large decreases in the conventional divertor coil current and associated torques in the toroidal field system are obtained when the current in the MHD coil is as little as 1 MA. To generate this current, flows of /spl sim/1 m/s are needed. The sensitivity of the separatrix to changing plasma or external coil currents is evaluated. Finally, the use of low activation metals in in the coil segments is evaluated.