Performance analysis of the European X-ray Free Electron Laser 3.9 GHz superconducting cavities performance analysis of the European ... M. Bertucci et al.

Abstract

The limits of performance of the European XFEL 3.9 GHz superconducting cavities were investigated. Most cavities exhibited high field Q slope, reaching the breakdown field at approximately 22 MV/m. We hypothesize that this limit is a feature of high frequency cavities and can be explained by a thermal model incorporating field dependent surface resistance. The results obtained from simulations were in good agreement with experimental data obtained at 2 K.