Gamma ray spectrometry for the identification of nuclear materials is valuable to homeland security. Identifying unknown sources, which may or may not be shielded, during radiation surveys requires full gamma-ray spectrum analysis including peaks and Compton scattering. This type of analysis would be laborious and time-consuming if all possible combinations of source and geometry data were tabulated and compared to an unknown measurement.


LLNL scientists have developed an approach for full spectrum analysis during gamma ray spectrometry using a spectral library signature created from a large amount of spectral data. The signature can be compared to unknown spectral measurements for the identification of previously unknown nuclear material.


  • Nuclide identification without prior knowledge of shielding or nuclear material form
  • Full gamma ray spectrum analysis
  • Automated, real-time analysis
  • Minimal computer processor time and resources required
Potential Applications

Nuclear material identification

Development Status

The Real Time Gamma-Ray Signature Identifier is described in U.S. Patent 8,180,579.

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