Quasi-helical symmetry in stellarators

Abstract

The quasi-helical stellarator, which was invented by Nuhrenberg and Zille in 1988, is a toroidal fusion concept that has the excellent alpha confinement of the axisymmetric tokamak without the disadvantages of major disruptions and current drive. Quasi-helical stellarators demonstrate the flexibility that exists in the tokamak and related toroidal configurations to circumvent critical problems in obtaining fusion power.