1. Rensselaer Polytechnic Institute, Department of Nuclear Engineering and Engineering Physics Troy, New York 12180
2. Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545
3. National Institute for Standards and Technology, Gaithersburg, Maryland 20899
4. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
5. EG&G Energy Measurements, Los Alamos, New Mexico 87544