MHD Dynamics in Beam-Injected LTX-$\beta$ Plasmas*

The implementation of a toroidal Mirnov array in the Lithium Tokamak eXperiment--Beta (LTX-$\beta$) has provided the means to study MHD stability and mode dynamics in neutral beam injected LTX-$\beta$ plasmas [D.B. Elliott et al. IEEE TPS April 2020]. PSI-Tri reconstructions enhanced by the addition of Thomson scattering profiles inform stability analysis, as well as providing key transport and profile parameters to model beam-plasma coupling. An array of particle tracking codes is employed to model fast ion confinement for comparison against experimental measurements, including pressure and temperature evolution, fueling as characterized by electron density, and the observed acceleration of MHD mode rotation in the counter-beam, counter-IP direction due to fast ion losses.