The status of the Daresbury Energy Recovery Linac Prototype

As part of the UK's R&D programme to develop an advanced energy recovery linac-based light source (4GLS) a 35 MeV technology demonstrator called the energy recovery linac prototype (ERLP) has been constructed. It is based on a combination of a DC photocathode electron gun, a superconducting injector linac and main linac operating in energy recovery mode, driving an IR-FEL. The priorities for this machine are to gain experience of operating a photoinjector gun and superconducting linacs; to produce and maintain high- brightness electron beams; to achieve energy recovery from an FEL-disrupted beam and to study challenging synchronisation issues. The current status of this project is presented, including construction and commissioning progress and plans for the future exploitation of this scientific and technical R&D facility.