Verification with gamma-ray and fast neutron detection.

We present the recent results of our development effort with liquid scintillators at Lawrence Livermore National Laboratory. Historically we developed many assay analysis techniques specifically for relatively low efficiency (a few percent) neutron measurement systems using thermal neutron detectors, mainly helium-3, taking advantage of the high thermal neutron interaction cross-sections. Recently, however, we have been investigating fast neutron detection with liquid scintillators and inorganic crystals. We have discovered considerable advantages with fast neutron detection because the inherent nanosecond production time-scales of fission and neutron-induced fission are preserved instead of being lost in neutron thermalization required for thermal neutron detectors. [ABSTRACT FROM AUTHOR]