Charge exchange recombination spectroscopy on the upgraded Lithium Tokamak eXperiment-$\beta $*

The Lithium Tokamak eXperiment-Beta (LTX-$\beta )$ has recently begun its initial campaign. LTX-$\beta $ has been operated with typical plasma currents \textgreater 85 kA and line averaged densities above 10$^{\mathrm{18}}$ m$^{\mathrm{-3}}$. A major part of the upgrade was the addition of neutral beam injection (NBI); NBI during the plasma has been achieved with extracted power of \textgreater 500 kW, more than 3x the average ohmic heating power. To capitalize on the NBI we have installed a new optical system for active charge exchange recombination spectroscopy (CHERS). The new CHERS system, intended to focus on lithium, will measure local impurity concentration, ion temperature, and toroidal velocity. The system has 52 total views, split into 4 groups of 13. The multi-view setup allows for major radii between 26 cm and 59 cm to be sampled with a \textasciitilde 2 cm spatial resolution. The plasma major radius has been 34-38 cm with a minor radius of \textasciitilde 20 cm. Half of the views face away from the beam so that the background can be simultaneously subtracted. The cameras used for CHERS have a typical sampling rate of 2.0-2.5 ms while the NBI duration is 5 ms and the plasma duration is \textgreater 40 ms. Beam optimization, initial charge exchange emission, and comparisons between the different spectrometers and emission lines will be highlighted.