[1] Karlsruhe Inst Technol, Inst Nucl Waste Disposal INE, D-76021 Karlsruhe, Germany
[2] European Synchrotron Radiat Facil, F-38043 Grenoble 9, France
[3] CEA Grenoble, SCIB CEA UJF, Lab Reconnaissance Ion & Chim Coordinat, INAC,UMR E 3, F-38054 Grenoble 09, France
[4] So Fed Univ, Fac Phys, Rostov Na Donu 344090, Russia
[5] Uppsala Univ, Dept Phys, SE-75121 Uppsala, Sweden
[6] Commiss European Communities, Joint Res Ctr, ITU, D-76125 Karlsruhe, Germany
[7] Univ Utrecht, Fac Geosci, NL-3508 Utrecht, Netherlands