Fast procedures for coincidence-summing correction in gamma-ray spectrometry

Uncertainties of calculated coincidence-summing correction factors in gamma-ray spectrometry

Uncertainty propagation to the γ-γ coincidence-summing correction factor from the covariances of the nuclear data and detection efficiencies have been formulated. The method was applied in the uncertainty analysis of the coincidence-summing correction factors in the γ-ray spectrometry of the 134Cs point source using a p-type coaxial HPGe detector.

Experimental assessment of the coincidence summing corrections in gamma-ray spectrometry of bulk samples

This work presents an experimental approach for estimation of the true coincidence-summing (TCS) correction for volume sources on the basis of TCS dependence on the source-to-detector distance. Firstly, it is shown that the TCS dependence on the source-to-detector distance can be linearized for point source geometry. If this linear dependence is established then TCS correction for an arbitrary source-to-detector distance can be obtained. In the case of a volume source a representative parameter d(V) can be formulated as the distance at which the point-source summing effect is the same as the one for the volume-source. Then if the TCS dependence on the source-to-detector distance is established for the point-source case and the volume-source d(V)-value is known, the TCS correction corresponding to the volume-source measuring geometry can be estimated. Experimental method and results are presented in the work too.

Intercomparison of methods for coincidence summing corrections in gamma-ray spectrometry--part II (volume sources)

The second part of an intercomparison of the coincidence summing correction methods is presented. This exercise concerned three volume sources, filled with liquid radioactive solution. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing corrective factors for several energies of (152)Eu and (134)Cs, and different source-to-detector distances. They are presented and discussed.

Reliability of two calculation codes for efficiency calibrations of HPGe detectors

This paper reports the reliability of efficiency calibrations for gamma-ray detectors using the calculation codes ANGLE and LabSOCS. For experimental verification, three HPGe detectors under various laboratory geometry configurations were used for this study. An overall comparison between experimental and calculated efficiency calibration curves is presented and comments on the various error sources affecting the final results are given. The deviations are generally below 10%, which could be acceptable for many applications.

A national campaign for coincidence-summing correction in gamma-ray spectrometry

A national campaign was carried out in Italy for the application of coincidence-summing correction in gamma-ray spectrometry. Twelve laboratories, belonging to the National Environmental Radioactivity Surveillance Network, took part in the campaign. They are equipped with gamma-ray spectrometry systems based on p- and n-type HPGe detectors with different relative efficiencies. A simplified procedure was used for coincidence-summing correction. This procedure requires a single-photon, single-nuclide source to measure the peak-to-total efficiency ratio at just one photon energy value. All the laboratories were given a 137Cs standard source for total efficiency determination, and a 134Cs source in the same geometry whose activity they had to determine. The results show the usefulness of the procedure. The average deviation of all the laboratory results from the ENEA-INMRI reference value was reduced from -12% before correction to +1% after correction. The paper gives a description of the different organisational aspects of the campaign, reports the results obtained and draws conclusions in which the gain in measurement accuracy is evaluated in the light of the effort required for each participant to perform the correction.