Measurement of a helical Pfirsch-Schliiter current with reduced magnitude in HSX

摘要

Measurements of the helical rotation and the reduction of the magnitude of the Pfirsch-Schliiter current compared to an equivalent tokamak are reported in a device that has quasihelical symmetry. The Pfirsch-Schliiter current is helical due to the lack of toroidal curvature, and is reduced in magnitude by the high effective transform. A 3D equilibrium reconstruction based on magnetic diagnostics agrees well with the profiles measured with Thomson scattering and diamagnetic flux loop measurements.