The work presented in this report is focused on the characterization and refinement of the HEVA approach, which combines the traditional 186-keV 235U signature with high-energy prompt gamma rays from neutron capture in the detector and surrounding collimator material, to determine the relative enrichment and 235U mass of the cylinder. The design of the HEVA modules (hardware and software) deployed in the current field trial builds on over seven years of study and evolution by PNNL and consists of a ø3×3 NaI(Tl) scintillator coupled to an Osprey digital multi-channel analyzer tube base from Canberra. In comparison to previous versions, the new design boosts the high energy prompt gamma-ray signature, provides more flexible and effective collimation, and improves count-rate management via commercially available pulse-processing electronics with a special modification prompted by PNNL.
Revised: January 25, 2017 |
Published: March 15, 2016