Compression of an Electron-bunch by Means of Velocity Bunching at ARES

ARES is a planned linear accelerator for research and development in the field of production of ultra-short electron bunches. The goal of ARES is to produce low charge (0.2 50 pC), ultra-short (from few fs to sub-fs) bunches, with improved arrival time stability (less than 10 fs) for various applications, such as external injection for Laser Plasma Wake-Field acceleration. The ARES layout will allow to perform and compare different kind of conventional e-bunch compression techniques, such as pure velocity bunching, hybrid velocity bunching (i.e. velocity bunching plus magnetic compression) and pure magnetic compression with the slit insertion. This flexibility will allow to directly compare the different methods in terms of arrival time stability and local peak current. In this paper we present simulation results for the compression of an electron bunch with 0.5 pC charge. We compare the case of pure velocity bunching compression to the one of a hybrid compression using velocity bunching plus a magnetic compressor.