The Confinement of High Temperature Plasma by the Heliotron Magnetic Fields

Abstract

A magnetic field named the Heliotron field is produced by electric current in a series of pair coils wound around a discharge tube at regular intervals. The electric current in each coil of the pair differs both in intensity and direction. The lines of force in this field undulate near the tube axis without cutting the wall, while those near the tube wall intersect the wall. Thus a high temperature plasma can be produced by ohmic heating in the central region of this field, and the plasma is prevented from touching the wall. This field is found to satisfy the necessary condition for equilibrium. The interchange instability of the plasma confined in this field is discussed. A general expression is given for the magnetic field, and it is shown that the Heliotron B magnetic field, the cylindrical cusp field, the helical winding field of the Stellarater and the Picket-Fence field are derived as special cases of this general formula.