ARES: Accelerator Research Experiment at SINBAD

ARES is a planned linear accelerator for R&D for production of ultra-short electron bunches. It will be hosted at the SINBAD facility, at DESY in Hamburg [1]. The goal of ARES is to produce low charge (0.2 - 50 pC), ultra-short (from few fs to sub-fs) bunches, with high arrival time stability (less than 10fs) for various applications, such as external injection for Laser Plasma Wake-Field acceleration [2]. The baseline layout of the accelerator foresees an S-band photoinjector which compresses low charge electron bunches via velocity bunching and accelerates them to 100 MeV energy. In the second stage, it is planned to install a third S-band accelerating cavity to reach 200 MeV as well as two X-band cavities: one for the linearization of the longitudinal phase space (subsequently allowing an improved bunch compression) and another one as a Transverse Deflecting Cavity (TDS) for longitudinal beam diagnostics. Moreover a magnetic bunch compressor is envisaged allowing to cut out the central slice of the beam [3] or hybrid bunch compression