Inductive sustainment of spheromaks

Inductive formation and sustainment of spheromaks are examined. The S-1 device utilizes a flux core to form a spheromak inductively. Plasmas are observed to relax during formation toward a minimum energy state, independent of initial conditions. Inductive sustainment of spheromaks is considered possible by utilizing this relaxation process. One method uses a poloidal flux transformer along the major axis, similar to the ohmic heating transformer in a tokamak. Alternatively, spheromaks can be established with the outermost poloidal field lines linked around the flux core to provide coupling between the plasma and external circuits. The spheromak configuration then can be sustained by oscillating the currents in the poloidal and toroidal field coils within the flux core. These proposed current drive schemes are investigated using the concept of magnetic helicity injection