PKU/IHIP, Beijing, People's Republic of China
DC-SRF photocathode injector developed by Peking University is a good candidate for obtaining high average current, low emittance, short electron beam pulse. Much progress has been made on the 3.5-cell cavity DC-SRF injector since SRF2009. The assembling of the cryomodule was completed with the 3.5-cell SRF cavity which has an accelerating gradient of 23.5MV/m in the vertical test. The preliminary RF experiment has been carried out soon after the installation and commissioning of 2K cryogenic system was finished. The accelerating gradient of the cavity is 11.5MV/m in a horizontal cold test and the Qext is 6×106 . The limitation of the gradient is mainly from our present low RF power source. Higher gradient is expected with a new 20kW solid state RF power source which will be delivered to Peking University soon.
SLAC, Menlo Park, California, USA
Fermilab, Batavia, USA
The TTF3-style coupler is typically used to power 1.3 GHz TESLA-type superconducting cavities. For the US ILC program, parts purchased in industry for such couplers are received at SLAC where they are inspected, cleaned, assembled as pairs in a Class 10 cleanroom, pumped down, baked at 150 degC and rf processed. The pairs are then shipped to FNAL and installed in cavities that are then tested at input power levels up to 300 kW. This paper describes the coupler results to date including improvements to the procedures and efforts to mitigate problems that have been encountered. Also progress on building a cold coupler section without e-beam wielding is presented.
