Validation of diamagnetic flux loop measurement with kinetic equilibrium reconstruction on LTX-β

During discharges in the Lithium Tokamak eXperiment -- β (LTX-β) significant eddy currents are driven in the first wall or shell, which is constructed of 1.6 mm stainless steel backed with a 10 mm copper layer, as well as the stainless steel vacuum vessel. These eddy currents, whose distributions are strongly 3D, complicate the use and interpretation of magnetic diagnostics in LTX-β. In particular, the diamagnetic flux loop, which is a valuable diagnostic of the stored energy and its evolution, exhibits pickup due to axisymmetric and 3D eddy currents that limit its accuracy. Experiments on LTX-β are intended to demonstrate improved confinement with lithium coatings on the plasma-facing shell surfaces, and experimental estimation of the stored energy and its evolution is crucial for that. Work to predict and compensate for eddy current pickup on these diagnostics will be presented. Eddy currents will be modeled using reconstructions, PSI-Tri, and time-dependent simulations, PSI-Tet. Studies of MHD activity and its effect on high performance discharges will also be presented.