JLAB, Newport News, Virginia
We present the status and recent results from the development of new SRF cavities for the CEBAF 12 GeV upgrade and for future light source applications. The JLab 12 GeV upgrade requires ten new high-performance CW cryomodules. These will each contain eight 7-cell cavities of a "low-loss" design with HOM damping sufficient for ~1mA of continuous current. Jlab has fabricated and tested a number of such cavities and demonstrated compliance with all 12 GeV project requirements with conventional BCP cavity processing. Recently we have also electro-polished several cavities of this type and shown significantly better performance than the standard BCP. This processing method could provide improved operational margin and lower cryogenic loads at the CEBAF working point. For future light source applications such as FELs or ERLs, cavities with higher beam current capability are desirable. Jlab has developed a high-current cavity for such applications with a cell shape optimized to minimize HOM power extraction and maximize the BBU threshold. We report on latest tests of this design and on plans to assemble a 2-cavity cryomodule for testing with beam in the recirculation loop of the JLab FEL.
