[1] IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011
[2] ST PATRICKS COLL,DEPT PHYS,MAYNOOTH,KILDARE,IRELAND
[3] HARVARD SMITHSONIAN CTR ASTROPHYS,WHIPPLE OBSERV,CAMBRIDGE,MA 02138
[4] NATL UNIV IRELAND UNIV COLL DUBLIN,DEPT PHYS,DUBLIN 4,IRELAND
[5] UNIV LEEDS,DEPT PHYS,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND