Helical Magnetic Axis Configuration Combined with l=1 and Weak l=−1 Torsatron Fields

Abstract

The superposition of a relatively weak l=−1 torsatron field on a main l=1 torsatron field leads to the improvement of the confinement properties due to the formation of a local magnetic well, which results from the local curvature of the helical magnetic axis with a larger excursion in the major radius direction. This l±1 helical magnetic axis system has a comparatively simple, compact coil structure. Here the vacuum configuration properties of l=±1 system are described.