Low recycling core and edge plasmas in LTX-β

LTX-β is currently vented for repair and modifications, with pumpdown scheduled for midsummer 2024. Modifications made during the vent include new porting for the neutral beam to increase the tangency radius by 50%, to significantly reduce the first orbit fast ion loss fraction, and increase beam coupling at higher power and injection energy. A new neutral particle analyzer will diagnose fast ion losses. Improvements have been made to the Thomson scattering system to increase signal to noise, especially for the separate APD-based high field side view. An additional Thomson scattering view of the scrape-off layer plasma will be installed during the upcoming campaign. A new high-field side limiter will be imaged by a two-color IR camera to diagnose the scrape-off layer (SOL) power deposition width. In a collaboration with Penn State University, a new remotely actuated liquid-filled lithium deposition system, which can be operated between shots, will be installed. LTX-β is fueled by a combination of high and low field side gas puffing, and a supersonic gas injector, as well as the neutral beam. An additional high field side gas nozzle surrounded by a small gas box is being added during this vent. A new diagnostic, Doppler Free Saturation Spectroscopy (DFSS), is being installed to diagnose the electric field which is expected to develop in the low collisionality SOL. First results from the reconfigured device will be discussed. Finally, prospects for full beam fueling with low recycling walls will be discussed, with emphasis on the very low collisionality SOL expected to result.