What is a stellarator?

A stellarator is a toroidal plasma confinement concept that uses effects that arise in the absence of toroidal symmetry to maintain the magnetic configuration without the need for current drive. The largest magnetic fusion machines under construction are stellarators, and the plasma parameters achieved in stellarators are second only to those in tokamaks. Stellarators are poised for rapid progress toward showing the feasibility of fusion power. The physics and mathematical concepts that are required to understand stellarators are reviewed. (C) 1998 American Institute of Physics.