Beam Dynamics of Energy Recovery Linacs

Abstract

Energy recovery linacs (ERLs) combine the advantages of the two major accelerator types used at present: the high currents and low energy consumption of storage rings and the rapidly accelerated, high-brilliance beams of linear ccelerators (linacs). As concepts from both accelerator types are adopted, similar beam physics challenges need to be overcome in the design of an ERL. In the first part of this article we describe the main requirements and layout options for an ERL’s beam optics, pointing out the individual demands of the various subparts of the ERL: injector, merger and splitter, linac section, and recirculator. In the second part, collective high-current effects are introduced with a focus on space charge, coherent synchrotron radiation, the microbunching instability, and beam break-up. A comprehensive list of references is given for readers interested in further details of the topics introduced.