1. Laboratoire National
des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
2. Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
3. University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom