Synthetic gamma-ray spectra for Homeland Security radionuclides analysis

Homeland Security applications use radiation detectors to identify radionuclides by gamma spectroscopy techniques. In order to check compliance of such systems to performance requirements, a computer code which predicts the gamma-ray spectra for various radiation detectors, as NaI(TI) and Ge was employed. The spectrum of a chosen radio-nuclide is generated according to its activity, its photo peak energy and yield (taken from data libraries). The detector efficiency, resolution and peak to Compton dependence are used to generate a pulse height spectrum for a specific detector. The developed program works with two main libraries of radioisotopes. One is a general library containing all practically encountered radioisotopes, and second library contains the fission products radioisotopes with half life higher than 1 min. The synthetic pulse height spectra can be used as input to evaluate the analysis ability of different systems and to investigate the efficiency of different shielding configurations.