1. Univ Lyon, ENS de Lyon, Univ Claude Bernard Lyon 1, CNRS, Laboratoire de Physique, F-69342 Lyon, France
2. Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France and CNRS, Institut NEEL, F-38042 Grenoble, France
3. Femto-ST, UMR 6174, F-25030 Besançon, France
4. Institute of Thermodynamics and Fluid Mechanics, Technische Universitaet Ilmenau, P.O. Box 100565, 98684 Ilmenau, Germany
5. CERN, CH-1211 Geneva 23, Switzerland
6. Université Grenoble Alpes, CNRS, Grenoble INP, LEGI, F-38000 Grenoble, France