1. Université Grenoble Alpes, CNRS, LiPhy, Grenoble, France
2. Institut Laue-Langevin, Grenoble, France. E-mails: jpeters@ill.eu, deme@ill.eu, gonthier@ill.eu, maurice@ill.eu, payre@ill.eu, lelievre@ill.eu
3. Institute of Physics, University of Tartu, Tartu, Estonia. E-mail: maksym.golub@ut.ee
4. Institute for Nuclear Research, Moscow, Russia
5. Institute of High Pressure Physics, Troitsk, Russia. E-mail: rsadykov@inr.ru