Physics Results from the LTX-$\beta$ Magnetics Upgrade

Lithium Tokamak eXperiment--Beta (LTX-$\beta$) has begun operating with increased magnetic fields, lithiated walls, and neutral beam core-fueling, allowing a new series of experiments into the low-recycling, high-performance regime previously observed in LTX [D.P. Boyle \textit{et al. PRL} July 2017]. Using the upgraded magnetic diagnostic suite [P.E. Hughes \textit{et al. RSI} Oct. 2018], we investigate the effect of the neutral beam on stored energy, plasma $\beta$, and MHD instability drive, and compare against previously observed LTX performance. Analysis techniques are explored to identify $n\leq5$ and $m\leq10$ MHD activity on the TA and REPA, and the SESA is studied for comparison to the eigenmode modeling of predicted shell eddy currents. Reconstructions in the PSI-Tri equilibrium code [C. Hansen \textit{et al. PoP} Apr. 2017], employing the full upgraded magnetic diagnostics suite now including a newly compensated diamagnetic loop, are compared against fast camera data and prior LTX reconstructions.