Formation and Sustainment of Field-reversed Configuration by Rotating Magnetic Field with Spatial High-harmonic Components

Abstract. Field-reversed configurations (FRCs) sustained by rotating magnetic fields (RMFs) with spatial highharmonic components have been studied in the metal flux conserver of the FRC injection experiment (FIX) apparatus. The high-harmonic RMF method has some unique features; (1) field lines of the RMF do not penetrate or cross the vessel wall, (2) selective penetration/exclusion of the fundamental/high harmonic RMF component will result in a generation of effective magnetic pressure near the separatrix, which helps to keep the separatrix away from the vessel wall, (3) strong azimuthal non-uniformity of the RMF will bring about the n = 4 deformation of the core FRC plasma, which will suppress the destructive modes caused by the rotation of the plasma column. The RMF with spatial high-harmonic components will provide quasi-steady current drive of high-beta FRC plasmas without destructive n = 2 rotational mode and will be helpful in reducing the particle loss and thermal load when applied to the fusion core plasma.