Calibration and Use of Germanium Spectrometers for the Measurement of Gamma-Ray Emission Rates of Radionuclides
|Publication Date:||12 May 1999|
This standard establishes methods for the calibration and use of germanium (Ge) spectrometers for the measurement of gamma-ray energies and emission rates over the energy range from 59 keV to approximately 3000 keV, and the calculation of source activities from these measurements. This standard establishes minimum requirements for automated peak finding and methods for measuring the full-energy peak efficiency with calibrated sources.
Performance tests are described that ascertain the proper functioning of the Ge spectrometer and evaluate the limitations of the algorithms used for locating and fitting single and multiplet peaks. Methods for the measurement of, and the correction for pulse pileup are suggested. A test to ascertain the approximate magnitude of coincidence summing is described. Techniques are recommended for the inspection of spectral-analysis results for large errors resulting from summing of cascade gamma rays in the detector. Suggestions are provided for the construction of data libraries for radionuclide identification, decay corrections, and the conversion of gamma-ray emission rates to decay rates.
This standard does not address the measurement of X-ray emission rates because X-ray peaks have intrinsically different peak shapes than gamma-ray peaks. Further, X-ray peaks are complex multiplets (e.g., the K X rays of Tl are composed of eight components that form four partially resolved individual peaks). Also, this standard does not address the measurement of emission rates of annihilation-radiati