Dipole moment of the Pfirsch-Schluter current in a finite beta stellarator plasma in heliotron E

A magnetic determination of the dipole moment of the Pfirsch-Schluter current in a finite beta stellarator/heliotron plasma is described. The rotating cosine saddle diagnostic coils and the poloidal flux loops are used to identify the dipole current in a finite beta toroidal plasma. A typical dipole moment of the toroidal current in the standard Heliotron E configuration is 0.6 kA.m, when the volume averaged beta is 0.50% at a magnetic field of 0.94 T. The measured equilibrium dipole current is practically proportional to the diamagnetic volume average beta available up to 0.95%. The observed dipole moment of the Pfirsch-Schluter current is compared with a magnetohydrodynamic (MHD) calculation for a finite beta stellarator plasma.