Minimum-average-B wells in linked magnetic mirror fields

Abstract

Minimum-average-B wells are examined for use in hydromagnetically stable linked mirror traps. A multipole expansion to fourth order in radius is used. The magnetic field shapes are chosen by a combination of heuristic and variational techniques to optimize the well radius. Numerical results show that the optimized wells are more practical than was previously realized, and that the required field shapes can be achieved with a simple coil configuration.