1. School of Physics and Astronomy and the Photon Science Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
2. The Cockcroft Institute, Sci-Tech Daresbury, Keckwick Lane, Daresbury, Warrington WA4 4AD, United Kingdom
3. Accelerator Science and Technology Centre, Science and Technology Facilities Council, Darebsury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD, United Kingdom