  The US will be contributing to the HL-LHC upgrade at CERN with the
fabrication and qualification of RFD crabbing cavities in the framework of the
HL-LHC Accelerator Upgrade Project (AUP) managed by Fermilab. AUP received
Critical Decision 3 (CD-3) approval by DOE in December 2020 launching the
project into the production phase. The electro-magnetic design of the cavity
was inherited from the LHC Accelerator Research Program (LARP) but needed to be
revised to meet new project requirements and to prevent issues encountered
during beam tests performed at CERN in the R&D phase. Two prototype cavities
were manufactured in industry and cold tested. Challenges specific to the RFD
cavity were the stringent interface tolerances, the pole symmetry, and the
higher-order-mode impedance spectrum. Chemical processing and heat treatments
were performed initially at FNAL/ANL and are now being transferred to industry
for the production phase. HOM dampers are manufactured and validated by JLAB. A
summary of cold test results with and without HOM dampers is presented.
