Poloidal field system design for the ZT-4OU reversed field pinch experiment

The poloidal field system in a reversed field pinch (RFP) provides two important functions. It induces the toroidal electric field that drives the plasma current over the duration of the discharge, and it provides the magnetic boundary conditions necessary for plasma equilibrium. In ZT-4OU, this functional dichotomy is achieved by using two separate systems of coils. The equilibrium winding, which provides the vertical field and field index necessary for plasma equilibrium, and the magnetizing winding, which provides the flux swing and magnetic energy necessary to set up and maintain the discharge. A cross sectional drawing and flux plot of the poloidal field system is shown