Status Report of the Superconducting 5-Cell Acceleration Structure at CERN

At CERN a 5 cell 500 MHz superconducting accelerating cavity has been constructed. At present the cavity is installed in the PETRA storage ring at DESY for a test run which will start middle of March. The cavity is equipped with a high power coupler and with 5 higher order mode couplers, two of the loop type and three of the antenna type. Frequency tuning and regulation are achieved by varying the length of the two end-cells. In a test of the complete cavity-cryostat system at CERN, acceleration fields of 2.8 MV/m and Q0-values above 109 have been reached. The cryostat losses remained below 10 W.