The Confinement of Plasma by the Heliotron Magnetic Field

Abstract

A magnetic field named the Heliotron field is produced by the electric current in a series of pair coils wound around the discharge tube with 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 these near the tube wall cross the wall. Thus the high temperature plasma can be produced by ohmic heating in the central region of this field being prevented from touching the wall. This field is found to satisfy the necessary condition for the 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.