OUTGASSING RATE OF HIGHLY PURE COPPER ELECTROPLATING APPLIED TO RF CAVITIES

We are planning to apply a new copper electroplating with a high purity and a high electric conductivity to normal-conducting rf cavities for electron or positron storage ringswith highbeamcurrents. As reportedin 2005Particle Accelerator Conference, our first test cavity, made of steel, with the electroplated copper surface finished up by electropolishing showed an excellent electric performance compared with the case of cavities made of oxygen free copper. Our next step is to examine the vacuum performance. This paper reports results of the outgassing-rate measurement on our second test cavity together with its fabrication process.