Feasibility study of Nb/Cu clad superconducting RF cavities

For the future large scale application of superconducting (SC) RF cavities like TESLA, one has to fabricate the cavities cheaply to achieve high gradients and high Q values (E/sub acc/>25 MV/m, Q>1/spl times/10/sup 10/). The amount of niobium material has to be decreased and the complex welding structure should be eliminated to reduce the fabrication cost. Here, the authors propose to fabricate seamless clad cavities of niobium and copper material and report the results of a feasibility study.