1. Catalysis Center and LANSCE, MS H805, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
2. Reactor Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
3. ICI Films, Drungans, P.O. Box 7, Dumfries, Scotland DG2 8NE, U.K.
4. IPNS, Argonne National Laboratory, Argonne, Illinois 60439