First test of a 1.5 GHz single cell accelerating cavity obtained by magnet sputtering of niobium

The first results of RF tests on a single cell copper niobium cavity operating at 1.5 GHz are presented. The cavity was obtained by spinning an oxygen-free/high-conductivity (OFHC) copper sheet in half cups and tubes. The cavity´s components are welded together under vacuum; the cavity thus obtained was niobium-coated by using a scaled version of the magnetron sputtering system developed at CERN for superconducting cavities operating at 350 and 500 MHz. The results of the first tests on two cavities together with ancillary measurements performed on several niobium samples are presented. The first attempt to produce a good 1.5-GHz cavity by sputtering niobium on a copper matrix was frustrated by some drawbacks in the film deposition process on the copper cavity.<>