Energy-recovery linacs for energy-efficient particle acceleration

Abstract

Energy Recovery Linacs (ERLs) are inherently energy-efficient because the RF power needed for acceleration is recovered during deceleration. Energy recovery enables extremely high-power beams which are not economically or ecologically possible using a simple Linac. The fundamental technology is not new but has taken on an increased importance in recent years. Here in this Review, I describe the positive aspects of the technology, the areas that are under active study to improve the overall efficiency, and areas that still need further R&D. The need for validation of the entire system will be explained and the active proposals described.