Note on the SC linear collider TESLA cavity design

The experience we have gained over the last few years from experiments with superconducting cavities for the TESLA test facility, justifies a revision of the design proposed almost five years ago. The proposed new design presented takes advantage of the high quality factor Q/sub 0/>10/sup 10/ and low electron emission at the specified accelerating field of 25 MV/m, as demonstrated by some tested cavities. The main aim of the design is to simplify production and preparation of superconducting cavities and thus to reduce the cost of the linear collider. The new cavity shape has an enlarged iris diameter with the following advantages: significantly lower loss factors, a simplified and less expensive scheme for the HOM damping and the suitability of hydroforming and higher stability of the field profile.