MAGNETOHYDRODYNAMIC EQUILIBRIUM OF HELICITY-INJECTED SPHEROMAK BY COMBINATION OF FDM AND BEM

Abstract

The sustainment of the spheromak has been successfully achieved by DC helicity injection in the FACT device at Himeji Institute of Technology. The flux conserver actually used in the experiments has the shielding wall to prevent the plasma from being in contact with the divertor bias coil. Equilibrium configurations of the spheromak in the flux conserver with the shielding wall and the divertor bias coil are numerically determined by using the combination of the finite difference and the boundary element method. Several results for equilibrium configurations and their equilibrium quantities are presented. On the basis of the results, the effects of the divertor bias coil on equilibrium configurations of the helicity-injected spheromak are investigated.