  It is well known that two fission fragments (FF's) are emitted essentially
back to back in the laboratory frame. That can be used widely in many
applications as a unique signature of fissionable materials. However, such
fission fragments are difficult to detect. The energy and angular distributions
of neutrons, on the other hand, are easy to measure, and that distribution will
carry information about the fission fragment's energy and angular spectra, as
well as the neutron spectra in the fission fragment rest frame. We propose to
investigate the two neutron correlation yield resulting from two FF's as a
function of different targets, the angle between the two neutrons and the
neutron energies. The preliminary calculation of the two neutron correlation
shows a huge asymmetry effect: many more neutrons are emitted anti-parallel to
each other than parallel to each other. That asymmetry becomes even more if the
energy cut on each neutron is done. This study will potentially permit a new
technique for actinide detection for homeland security and safeguards
applications as well as improve our knowledge of correlated neutron emission.
