Performance comparison of a new approach to nuclear spectral analysis with commercial codes

The performance of a new approach to nuclear spectral analysis was compared with two widely accepted commercial codes. The comparison measured the new approach's ability to determine the presence and activity of multiple nuclides in spectra dominated by natural background. The new approach is implemented in the spectral analysis software, RobWin/sup TM/. Ten calibration sources ranging in activity from 25 to 450 kBq were placed 20.5 meters from a bare, 100% relative-efficient high purity germanium gamma-ray detector, thus assuring dominance of the natural background radiation over the test nuclides. Accumulated spectra were recorded at ever-doubling time intervals from 225 seconds to 128 hours. All spectra were analyzed by each code according to a defined procedure designed to achieve the best results from the comparator codes. The results from all codes were in general agreement for most nuclides where acquisition times were long, but RobWin's performance was significantly superior for short counting times.