1. Department of Physics and Astronomy, Department of Chemistry, BMC, Uppsala University , Husargatan 3 , 752 37 Uppsala , Sweden
2. Department of Physics, University of Rome Tor Vergata and Istituto di Fisica Nucleare (INFN), Via della Ricerca Scientifica 1 , 00133 Roma , Italy
3. Hystorical Museum for Physics and Enrico Fermi Studies and Research Center, Department of Physics, University of Rome Tor Vergata and Istituto di Fisica Nucleare (INFN), Via della Ricerca Scientifica 1 , 00133 Roma , Italy
4. Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Via Panisperna 89a , 00184 Roma , Italy