[1] UNIV LUND,DEPT PHYS,S-22101 LUND,SWEDEN
[2] GUSTAF WERNER INST,UPPSALA,SWEDEN
[3] CEN,F-38041 GRENOBLE,FRANCE
[4] INST SEDIMENTARY & PETR GEOL,CALGARY T2L 2A7,ALBERTA,CANADA
[5] UNIV BERGEN,DEPT PHYS,N-5014 BERGEN,NORWAY
[6] NIELS BOHR INST,COPENHAGEN,DENMARK
[7] IST NAZL FIS NUCL,CATANIA,ITALY