1. Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
2. ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
3. European Spallation Source, 22100 Lund, Sweden
4. Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, United Kingdom
5. Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
6. Department of Physics, University of York, York YO10 5DD, United Kingdom