Energy-angle correlation of neutron emission from 235U induced ?ssion

Year
2013
Author(s)
Karen Henderson - U.S. Nuclear Regulatory Commission
R.C. Haight - Los Alamos National Laboratory
A Enqvist - Department of Nuclear Engineering and Radiological Sciences, University of Michigan
S. D. Clarke - Department of Nuclear Engineering & Radiological Sciences, University of Michigan
S. A. Pozzi - Department of Nuclear Engineering & Radiological Sciences, University of Michigan
B. Wieger - University of Michigan
Hye Young Lee - Los Alamos National Laboratory
Ching-Yen Wu - Lawrence Livermore National Laboratory
Abstract
Correlated neutrons from induced 235U ?ssions were measured using a purposely built measurement system based on EJ-309 organic liquid scintillation detectors. The ?ssion chamber built at Lawrence Livermore National Laboratory used at the Los Alamos Neutron Science Center enabled highly resolved measurements of individual ?ssion events. Multiple neutrons from such events were detected and analysed with respect to their energy-angle and numberangle correlations. The results show a high correlation with angle, both the number of neutrons and their energy are highly correlated as a function of their relative angle. This leads to large differences in the number of detected neutrons and their energies when detecting (prompt) ?ssion neutrons. The measurements ?nd similar trends for 235U as have been found for spontaneous ?ssion in 252Cf.