The 1995 IAEA intercomparison of γ-ray spectrum analysis software (original) (raw)
Related papers
An intercomparison of software for processing Ge γ-ray spectra
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1998
An intercomparison of software for the analysis of -ray spectra from Ge detectors was carried out by testing the quality of calculated areas and associated uncertainties of well-isolated single peaks from IAEA test spectra. The results of the intercomparison show that the quality of results from -spectrometric analyses of radionuclides providing well-isolated single peaks (e.g. Cs) vary significantly between software packages. The results furthermore indicate significant effects on the quality from the user of the software. The intercomparison comprised tests of precision and accuracy, and permitted a ranking of the results according to accuracy. Fifteen sets of data were submitted for the intercomparison involving ten software packages. Only four of the 15 data sets showed both acceptable precision and accuracy, and the accuracies of the other data sets were tested against the results of one of these sets to provide a ranking between the data sets. Seven data sets show high accuracy, five data sets show average accuracy and three data sets show low accuracy. Generally, the data sets based on sophisticated methods for calculating peak areas (e.g. peak fitting) do not show higher accuracy than those based on more simple methods.
As a first step after installation of new software and hardware in the Neutron Activation Analysis (NAA) laboratories of Nigeria Research Reactor-1 (NIRR-1) the calibration of the spectrometer was carried out before any spectral analysis could be done. Both electronic spreadsheet and dedicated spectral analysis software (k0-IAEA) were employed and the results obtained from both methods were compared in this study. The efficiency curves were established from measurement and interpretation of several spectra from nine standard gamma-ray calibration sources (Na-22, Mn-54, Co-57, Co-60, Y-88, Cs-137, Eu-152, Ra-226, Am-241) whose activities are known to better than ±3%. The sets of values obtained for the full-energy peak detection efficiency from the two approaches are close at higher geometries with less than 10% variation.
Dechaos — A program for automatic or interactive analysis of gamma-ray spectra
Journal of Radioanalytical and Nuclear Chemistry Articles, 1995
DECHAOS is a gamma-ray spectral analysis program for personal computers. The program offers two modes of operation, automatic or interactive. The spectra to be analyzed can be acquired using any pulse height analyzer. The program includes routines for energy calibration, peak shape and efficiency calibration. Complex mulfiplets can be resolved automatically with the peak areas being determined using lesst-squares fitting techniques. Output tables include all data used in the calculation and peak information. The program is public domain software.
Review Article : Applicable methods of evaluating peak area of gamma ray spectra
Maǧallaẗ ǧāmiʻaẗ al-anbār li-l-ʻulūm al-ṣirfaẗ, 2022
Gamma ray spectra have interesting information about energy and intensity of gamma photons. Normally, this information is available in the peak area and background region. A full energy peak sits on a background continuum and produced by full energy absorption of high energy photons, while background region is produced by Compton scattering of the photons. The most essential concern of errors is in the method of determining the events in both peak and background areas. The uncertainty is low when the background counts are small relative to the peak counts. However, it becomes high when the counts of the peak area are low with respect to that of background. The detection threshold for the peak is ultimately determined by the uncertainty in the background counts. This depends on the technique used and the form of the produced spectra. This paper reviews different methods of determining peak area and their associated uncertainties in terms of the principle and application of the techniques used. .
Applied Radiation and Isotopes, 2011
In the gray spectrometric analysis of the radionuclides, a correction factor is generally required for the spectral interfering grays in determining the net areas of the analytical peaks because some interfering grays often might contribute to the analytical peaks of interest. In present study, a correction methodology for the spectral interfering grays (CSI) is described. In particular, in the analysis of 232 Th contained in samples, the interfering grays due to 226 Ra, 235 U, 238 U and their decay products often overlap to the peaks of interest from 232 Th decay products, and vise versa. For the validation of the proposed CSI method, several certified reference materials (CRM) containing U and Th were measured by using a 76.5% efficient n-type Ge detector. The required correction factors were quantified for spectral interference, self-absorption and true coincidence summing (TCS) effects for the relevant grays. The measured results indicate that if one ignores the contributions of the interfering grays to the analytical peaks at 583.2 keV of 208 Tl and 727.3 keV of 212 Bi, this leads to a significantly systematic influence on the resulted activities of 232 Th.
Gamma-ray calibration energies: a review of the 192Ir data
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1993
In order to perform evaluations by the least-squares method, the complete covariance matrix for the gamma-ray energy standards is needed . Some errors due to excluding the covariances from the statistical analysis are pointed out. The gamma-ray energies of 1921r and 198Au, measured with curved-crystal spectrometers, were reanalyzed and the covariances between results determined . The gamma-ray energies were updated by including the latest values of the fundamental constants. The covariance matrix between gamma-ray energy data and the fundamental constants is deduced, so that the energy values can be updated correctly if new measurements are performed or if the fundamental constants are reevaluated .
Applied Radiation and Isotopes, 2019
The probabilities of locatingdetecting peaks with a high relative peak-area uncertainty were determined empirically with nine types of peak-location software used in laboratories engaged in gamma-ray spectrometry measurements. It was found that it is not possible to locate the peaks with a probability of 0.95, for those peaks that have a relative peak-area uncertainty in excess of 50%. LocatingIdentifying peaks at these relative peak-area uncertainties with a probability greater than 0.95 is only possible in the librarydriven mode, where the peak positions are supposed a-priori. The deficiencies of the library-driven mode and the possibilities to improve the probabilities of locating peaks are briefly discussed.
A method for calculating the decision thresholds for gamma-ray emitters, identified in gamma-ray spectrometric analyses, is described. In the calculation, the number of counts and the uncertainty in the number of counts for the peaks associated with the emitter are used. The uncertainty in the number of counts used in the calculation was computed using Canberra's Standard Peak Search Program (Canberra, 1986. Peak Search Algorithm Manual 07-0064). For isolated peaks, the decision threshold exceeds the value calculated from the channel contents in an energy region that is 2.5 FWHM wide, covering the background in the immediate vicinity of the peak. The decision thresholds vary by approximately 20% over a dynamic range of peak areas of about 1000. In the case of overlapping peaks, the decision threshold increases considerably. For multi-gamma-ray emitters, a common decision threshold is calculated from the decision thresholds obtained from individual gamma-ray emissions. The common decision threshold is smaller than the smallest of the individual decision thresholds.
STATISTICAL DATA ANALYSIS OF GAMMA-RAY BACKGROUND SPECTRA FOR QUALITY ASSURANCE PURPOSES
2010
Twenty five gamma-ray spectra were accumulated in the gamma-ray spectrometry laboratory located at the Chemistry Division, PINSTECH, Islamabad over a period of three years. Different background components along with their variation with time have been discussed in this paper. It was found that natural component of the background radiations can be reduced with a better design of shielding around the detector. However, the component from the fission products cannot be reduced by increased shielding but with a better shielding material containing less or no fission products.