Analysis of Uranium Enrichment with New CZT Detectors

Gamma-ray spectroscopy is a well-established nondestructive method for determiningthe %U-235 enrichment of uranium in containers. The techniques developed for thisinvolve the analysis of various portions of the gamma-ray spectrum. LLNL has developedan analysis code that determines the enrichment from high-resolution gamma-rayspectroscopy using the 100 keV region. In the past, we have adapted this method to theanalysis of spectra from CZT detectors. It was found that the detectors available ~10years ago had marginal energy resolution and complex line shapes that greatly limitedthe effectiveness of the analysis. In the last few years new pixelated CZT detectors withadvanced signal processing have been developed which should dramatically enhancethe enrichment determinations. We are adapting the LLNL code to analyze data fromthese systems. In this paper, we will describe our efforts in modifying the code and willdescribe the results of the analysis of new data acquired with these types of systems.These analyses will help define the performance of CZT systems as a function of therange of enrichments and various experimental conditions.