1. School of Environment and Life Sciences, Peel Building, University of Salford, Salford, UK
2. School of Environment and Life Sciences, Peel Building, University of Salford, Salford M5 4WT, UK
3. Lasers for Science Facility, Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, UK
4. MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
5. Department of Physics, SUPA, University of Strathclyde, Glasgow, UK