A comparison of NIMROD simulations of RMF current drive with 3-axis probe data from the TCSU experiment

The NIMROD code has been adapted to simulate the formation and sustainment of FRCs using Rotating Magnetic Fields (RMF) [R.D. Milroy, C.C. Kim and C.R. Sovinec, Phys. Plasmas, {\bf17}, 062502 (2010)]. Calculations have been performed with the magnetic boundary conditions adjusted to match those of recent experimental measurements as closely as possible. First the n=0 flux on the radial wall is set to match that measured in the experiment, and secondly the n=1 fields imposed are made to approximate the boundary fields measured by the recently installed 3-axis probe. The experimental measurements were made with a new 3-axis probe that was installed on TCSU shortly before its final shut-down. This probe has 90 windings that can simultaneously measure B$_{r}$, B$_{\theta}$, and B$_{z}$ at 30 radial positions. Calculations and experiments were performed with both even-parity and odd-parity antenna sets. For both cases, a comparison of the steady n=0 component of the calculated field shows a very similar structure to that obtained with experimental measurements.