"Development of a Portable Neutron Coincidence Counter for Field Measurements of Nuclear Materials using the Advanced Multiplicity Capabilities of MCNPX 2.5.F and the Neutron Coincidence Point Model,"
M.S. Thesis, Texas A & M University, December 2007.
Neutron coincidence counting is an important passive
Nondestructive Assay (NDA) technique widely used for qualitative
and quantitative analysis of nuclear material in bulk samples.
During the fission process, multiple neutrons are simultaneously
emitted from the splitting nucleus. These neutron groups are often
referred to as coincident neutrons. Because different isotopes
possess different coincident neutron characteristics, the
coincident neutron signature can be used to identify and quantify a
given material. In an effort to identify unknown nuclear samples in
field inspections, the Portable Neutron Coincidence Counter (PNCC)
has been developed. This detector makes use of the coincident
neutrons being emitted from a bulk sample. An in-depth analysis has
been performed to establish whether the nuclear material in an
unknown sample could be quantified with the accuracy and precision
needed for safeguards measurements. The analysis was performed by
comparing experimental measurements of PuO2 samples to the
calculated output produced using MCNPX and the Neutron Coincidence
Point Model. Based on the analysis, it is evident that this new
portable system can play a useful role in identifying nuclear
material for verification purposes. See Document
Associated Project(s):Safeguards Instrumentation Development for Measuring Pu via Coincident Neutron-Gamma Signals