Performance of the first refurbished CEBAF cryomodule

The Thomas Jefferson national accelerator facility has begun a cryomodule refurbishment project. The goal of this project is robust 6 GeV, 5 pass operation of the continuous electron beam accelerator facility (CEBAF). The scope of the project includes removing, refurbishing and replacing 10 CEBAF cryomodules at a rate of three per year. Refurbishment includes reprocessing of SRF cavities to eliminate field emission and increase the nominal gradient from the original 5 MV/m to 12.5 MV/m. New "dogleg" couplers between the cavity and helium vessel flanges will intercept secondary electrons that produce arcing on the 2 K ceramic window in the fundamental power coupler (FPC). Modification of the Qext of the FPC will allow higher gradient operations. Other changes include new ceramic RF windows for the air to vacuum interface of the FPC and improvements to the mechanical tuners. Any damaged or worn components will be replaced as well. Currently, the first of the refurbished cryomodules has been installed and tested both in the cryomodule test facility and in place in the North Linac of CEBAF. This paper will summarize the results of these tests.