Plasma Processing R&D for the SNS Superconducting Linac RF Cavities

The Spallation Neutron Source routinely operates with a proton beam power of 1 MW on its production target. A plan to reach the design 1.4 MW within a few years is in place [1] and relies on increasing the ion beam current, pulse length and beam energy in the linac. The increase in beam energy from the present 930 MeV to 1 GeV will require an increase of approximately 15% in the accelerating gradient of the superconducting linac highbeta cryomodules. In-situ plasma processing was identified as a promising technique to reduce electron activity in the SNS superconducting cavities and increase their accelerating gradient [2]. R&D on plasma processing aims at deploying the new in-situ technique in the linac tunnel by 2016. Overall plan and current status of the plasma processing R&D will be presented.