Development of advanced laserwire accelerator diagnostics and laser controlled particle beams

The proposed research will implement a laserwire at the new FETS accelerator at RAL, to measure the transverse emittance of the high power 3 MeV hydrogen ion beam. The technique will be developed to monitor the longitudinal bunch structure via ultrafast laser pulses. We propose new concepts for laser controlled particle beams, based on the photo-detachment of accelerated ions and the extraction of an adjustable intensity, steerable proton beam, suitable for medical and accelerator applications.

The Front End Test Stand (FETS) under construction at the Rutherford Appleton Laboratory (RAL) is the UK's contribution to research into the next generation of High Power Proton Accelerators (HPPAs). HPPAs are an essential part of any future Spallation Neutron Source, Neutrino Factory, Muon Collider, Accelerator Driven Sub-critical System, Waste Transmuter etc. FETS will demonstrate a high quality, high intensity, chopped H-minus beam and is a collaboration between RAL, Imperial College, Royal Holloway University of London, and the University of Warwick in the UK, as well as the Universidad del Pais Vasco and ESS-Bilbao in Spain.

Beam chopping will be an important feature of the next generation of HPPAs. The requirement to minimise the need for remote handling of accelerator components dictates that beam loss in future machines must be kept to levels comparable to those of current facilities in order to avoid activation. With beam powers an order of magnitude or more than those currently achieved, fractional beam loss must necessarily be reduced by a similar factor. The FETS project will be able to demonstrate the techology required for beam chopping in future HPPAs.

Originally conceived simply as a chopper beam test, the FETS has since expanded its objectives to become a generic test stand for technologies related to the front end of several proposed projects which require a high-power proton driver, as mentioned above. A secondary objective of FETS was to encourage the study of accelerator technology by a new generation of accelerator engineers and physicists in UK universities. The quality of the work being produced by the (mostly) young team working on FETS is testament to the success of this objective. FETS has also resulted in a fruitful collaboration between RAL/ISIS and the ESS-Bilbao project in Spain. The exchange of ideas, experience and hardware is proving extremely beneficial to both sides. The work undertaken has contributed to the UK's continuing international reputation as a centre of excellence and has stimulated collaborations with leading international accelerator institutes such as CERN, FNAL, ESS and CNS.