1. Istituto Officina dei Materiali CNR, Laboratorio TASC, S.S. 14 km 163.5,
I-34149 Trieste, Italy
2. Università di Trieste, Dipartimento di Fisica, Via Valerio 2, I-34127
Trieste, Italy
3. St. Petersburg Academic University, Khlopina 8/3, 194021 St. Petersburg, Russia
4. Durham University, Stockton Road, Durham DH1 3L, U.K.
5. Ioffe Physical Technical Institute of the Russian Academy of Sciences, Politekhnicheskaya 26, 194021 St. Petersburg, Russia
6. Sincrotrone Trieste S.C.p.A., Elettra Laboratory, S.S. 14 km 163.5, I-34149 Trieste, Italy