  Background: Spontaneous fission events emit prompt neutrons correlated with
one another in emission angle and energy. Purpose: We explore the relationship
in energy and angle between correlated prompt neutrons emitted from 252Cf
spontaneous fission. Methods: Measurements with the Chi-Nu array provide
experimental data for coincident neutrons tagged with a fission chamber signal
with 10 degree angular resolution and 1 ns timing resolution for time-of-flight
energy calculations. The experimental results are compared to simulations
produced by the fission event generators CGMF, FREYA, and MCNPX-POLIMI
IPOL(1)=1. Results: We find that the measurements and the simulations all
exhibit anisotropic neutron emission, though differences exist between fission
event generators. Conclusions: This work shows that the dependence of detected
neutron energy on the energy of a neutron detected in coincidence, although
weak, is non-negligible, indicating that there may be correlations in energy
between two neutrons emitted in the same fission event.
