Novel X-band transverse deflection structure with variable polarization

The growing request for sophisticated electron beam manipulation techniques for the optimization of Free Electron Lasers (FELs) or novel acceleration techniques requires enhanced beam control capabilities  and characterization. One of the most important challenge is the development of new diagnostic techniques able to characterize the longitudinal phase space of the beam, including spatial correlation terms, with a resolution in the range of a few tens of fs to sub-fs. To address this requirement, in the last few years, a collaboration between DESY, PSI and CERN has developed and built an advanced modular X-band transverse deflection structure (TDS) system with the new feature of providing variable polarization of the deflecting force. The possibility of changing the orientation of the streaking field of the TDS to an arbitrary azimuthal angle opens new opportunities for extended 3D beam characterizations. We believe that, similarly to what has happened previously with the development of X-band single-polarized TDS at SLAC, which has enabled relevant novel methods of optimization of FELs, this enhanced version will open new frontiers allowing unprecedented electron beam control and optimization.