Affiliation: | * Space Science Department of ESA, ESTEC, Keplerlaan, 2200 AG, Noordwijk, The Netherlands ** Central Research Institute for Physics, PO Box 49, H-1525, Budapest 114, Hungary *** Space Research Institute, Profsoyuznaya 84/32, 117810, Moscow GSP-7, USSR † Max-Planck-Institut für Kernphysik, Postfach, 103980, D-6900, Heidelberg, FRG ‡ Unit for Space Sciences, University of Kent at Canterbury, Canterbury CT2 7NR, UK § PTS, Leinerweberstr. 60, D-7800, Freiburg, FRG |