J. Jonkers
Department ofPhysics, Eindhoven University ofTechnology P.O. Box 513,5600 MB Eindhoven, The Netherlands
Joost J. A. M. van der Mullen
Department of Applied Physics, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands
D. C. Schram
Dept. of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands