In this work, we use the three-dimensional resistive MHD code NIMROD to investigate the impact of resistivity inhomogeneity on the sawtooth process of a cylindrical reversed field pinch (RFP) plasma. The simulation employs a non-uniform resistivity profile similar to experiments, which monotonically increases from the core to the edge as the temperature decreases. The resistivity inhomogeneity introduces an additional electric field in the plasma, which accelerates the inward diffusion of magnetic flux and changing the self sustained reversal state, hence significantly enhances the dynamo effect and the sawtooth process in the RFP plasma.
This paper investigates how non-uniform resistivity in a reversed field pinch (RFP) plasma can enhance the dynamo effect and sawtooth relaxation process. The simulation shows that a resistivity profile that increases from the core to the edge accelerates magnetic flux diffusion, changing the self-sustained reversal state and significantly enhancing the dynamo and sawtooth behavior.