Overview of High Field Side Lower Hybrid Current Drive Experiment at DIII-D

High field side lower hybrid current drive (HFS LHCD) is a potential tool for efficient, off axis current drive. From simulations, efficient off-axis current at r/a~0.6-0.8 with peak current density up to 0.4 MA/m² and 0.4 MA/MW coupled is achievable for target DIII-D discharges. From the HFS, LH waves are expected to have improved accessibility and single pass absorption due to favorable wavenumber upshift. A compact coupler utilizes a traveling wave, 4-way splitter and a multi-junction to distribute power poloidally and toroidally, respectively, and imbedded matching structures to maximize performance. Laser Powder Bed Fusion (LPBF) GRCop-84, a high strength, thermal and electrical conductivity copper alloy, is used for the coupler and in-vessel waveguides allowing for embedded RF elements and waveguides with precise twists and bends. Klystron commissioning has begun and the klystrons have been conditioned up to 20 kW into dummy load for short pulse. The in-vessel waveguides and coupler have been assembled on the DIII-D vessel mock-up and are expected to be installed in 2023 vent. Initial HFS edge density measurements suggest the coupling is quiescent and within range the coupler was optimized. The latest results and system status will be presented.