1 Laboratoire d’Optique Appliquee, Ecole Polytechnique, Palaiseau, 91128, France
2 STFC Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX, United Kingdom
3 University of Strathclyde, Glasgow G1 1XQ, United Kingdom
4 Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ, United Kingdom
5 Graduate School of Engineering, Osaka University, Japan
6 Queens University Belfast, Belfast BT7 1NN, United Kingdom
7 University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
8 University of Cambridge, Cambridge CB2 1TQ, United Kingdom
9 GoLP/Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisbon, Portugal