Method to reduce microphonics in superconducting resonators

The control of superconducting resonators requires a large amount of rf power due to their narrow bandwidth and the presence of microphonics in the ambience, although only a small part is dissipated inside the resonator to generate the accelerating field. A simple and innovative method has been devised to reduce the effect of microphonics on the quarter-wave resonators. Experiments have been conducted successfully at room temperature and at 4.2 K to demonstrate the effect of the new damping mechanism. A detailed report of the experiments with the superconducting resonators in a test cryostat and an on-line linac cryostat is presented in this paper.