[1] Univ Roma La Sapienza, Dept Phys, Rome, Italy
[2] Fdn Policlin Univ Campus Bio Med, Dept Operat Res, Unit Radiat Oncol, Rome, Italy
[3] Univ Roma La Sapienza, Dept Sci Base & Applicate Ingn, Rome, Italy
[4] INFN Ist Nazl Fis Nucl, Sect Roma 1, Rome, Italy
[5] Museo Storico Fis, Rome, Italy
[6] Ctr Studi Ric Fermi, Rome, Italy
[7] Univ Roma La Sapienza, Dept Dipartimento Sci & Biotecnol Med Chirurg, Rome, Italy