Status And Test Results Of High Current 5-CELL SRF Cavities Developed At Jlab

The development of a new compact CW cryomodule for use in future Energy Recovery Linacs (ERLs) and Free Electron Lasers (FELs) is underway at JLab with the objective of transporting beam current up to Ampere-levels. Design goals include broadband cavity Higher Order Mode (HOM) damping, HOMs tuned to safe frequencies to minimize the power extracted from the beam, good real-estate gradient and cryogenic efficiency and consideration of cost and maintainability. Two 1497 MHz high current niobium five-cell cavities with waveguide end groups have been manufactured recently. We report on the latest results including high field tests in a vertical Dewar at 2K and a detailed assessment of the impedance budget for beam breakup (BBU) instability. The general cryomodule and cavity concept is described as well.