Mechanical design and operational improvement for Phase 2 of HAYSTAC*

The HAYSTAC experiment seeks to detect dark matter axions through their resonant conversion to radiofrequency electromagnetic waves in the presence of a magnetic field. HAYSTAC’s sensitivity is enabled by a tunable, resonant microwave cavity embedded in a 9 T magnetic field. Phase 1 of HAYSTAC achieved the first exploration of the QCD axion model band above 20 $\mu$eV. I will describe the mechanical and experimental upgrades made to HAYSTAC in preparation for Phase 2, including improvements to the cryogenics and mechanical control systems.