Direct Comparison of Simulated Sawtooth Evolution to the Madison Symmetric Torus RFP

It has long been believed that the reversed field pinch has stochastic magnetic field lines and exhibits Rechester-Rosenbluth thermal transport under standard operating conditions. In this poster, results from a set of first principles simulations using the resistive MHD code DEBS will be presented. The simulations are designed to match experimental data as closely as possible. To that end, both a Spitzer and a neoclassical resistivity model were tried for the cases of a fixed, experimentally measured resistivity. A freely evolving resistivity based on an evolving pressure profile was also examined. The fixed resistivity calculations were done at a Lundquist number of $10^6$ and the evolving pressure calculations had an average Lundquist number of approximately $4\times10^6$. The expected Rechester-Rosenbluth electron thermal diffusion, $\chi_{_{RR}} = v_{_{T_e}} \pi L_{_{eff}} \tilde{b}^2/B^2$, is compared to the measured thermal diffusion obtained through power balance. Furthermore, in the evolving pressure case, the temperature profile information is extracted and compared directly to Thomson scattering measurements.