The Drive Beam Decelerator of CLIC

In the Compact Linear Collider (CLIC) a high-current, low-energy beam will be decelerated in a chain of power extraction structures to produce the RF-power necessary to accelerate a low-current, high-energy beam in the main linac. The transverse dynamics of the decelerated beam is discussed, based on results of the programs WAKE [1] and PLACET [2]. The very large energy spread and strong transverse wakefields as well as the high group velocity of these fields and the considerable length of the bunch train are important factors. Static and dynamic imperfections are considered including ground motion. The choice of parameters for the structures is investigated. A promising beam-based alignment technique is presented that makes use of a low emittance beam.