CEBAF energy recovery experiment

A successful GeV scale energy recovery demonstration with high ratio of accelerated-to-recovered energies (50:1) was recently carried out on the CEBAF recirculating linear accelerator. Future high energy (multi-GeV), high current (hundreds of milli-Amperes) beams would require gigaWatt-class RF systems in conventional linacs - a prohibitively expensive proposition. However, invoking energy recovery [1] alleviates extreme RF power demands; required RF power becomes nearly independent of beam current, which improves linac efficiency and increases cost effectiveness. Furthermore, energy recovering linacs promise efficiencies of storage rings, while maintaining beam quality of linacs: superior emittance and energy spread and short bunches (sub-pico sec.). Finally, energy recovery alleviates shielding, if the beam is dumped below the neutron production threshold. Jefferson Lab has demonstrated its expertise in the field of Energy Recovery Linacs (ERLs) with the successful operation of the Infrared FEL, where 5 mA of average beam current have been accelerated up to 50 MeV and the energy stored in the beam was recovered via deceleration and given back to the RF power source. To date this has been the largest scale demonstration of energy recovery.