One-dimensional simulations of reversed field pinch discharges

A simple one-dimensional time-dependent model for simulating the magnetic field profiles in a reversed field pinch (RFP) plasma is presented. The model, which is derived from basic MHD equations with the addition of a phenomenological dynamo electric field, is able, through the tuning of a few free parameters, to simulate the time evolution of RFP discharges in a large range of operating conditions, successfully reproducing quantities such as the average toroidal field, the loop voltage and the on-axis safety factor. The application to several experimental conditions obtained on the RFX-mod machine [ P. Sonato et al., Fusion Eng. Des. 66, 161 (2003) ], including oscillating poloidal current drive (OPCD) is shown and the simulation outcome is discussed.