1. Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom
2. School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, United Kingdom
3. Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
4. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
5. Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom