Experimental verification of gamma-efficiency calculations for scintillation detectors in ANGLE 4 software

Abstract

ANGLE software for semiconductor detector efficiency calculations - long existing and widely accepted tool in quantitative gamma spectrometry - has been recently extended to scintillation NaI detectors. The extension features in the latest edition (ANGLE 4) and it is briefly outlined. Discretization of reference efficiency curve, meaning possibility of using ANGLE 4 for particular gamma energies without constructing the complete reference efficiency curve, is particularly emphasized. This yields both in enhanced practicality and higher accuracy, while reducing the potential for systematic errors. The present work is primarily focussed on experimental verification of ANGLE 4 for NaI detectors. Two detectors (2 ? 2 and 3 x 3 inches) were employed in the experiment. Commercially calibrated gamma sources (in the forms of quasi point and cylinder) and homemade solutions (diluted from calibrated ones) were measured at various distances from the detector(s), ranging 0 cm to 50 cm. Energy range observed was 59 keV to 1408 keV. Versatility of counting conditions, in terms of detectors and sources used, gamma energies observed, source detector separations, etc., was aimed at creating as large experimental evidence as possible for verification purposes. Experimentally obtained efficiencies are compared with those calculated by ANGLE 4. Very good agreement is obtained - well within the experimental uncertainties - thus proving the reliability of the software.

Calibration of 4π NaI(Tl) detectors with coincidence summing correction using new numerical procedure and ANGLE4 software

“…-offering practically unlimited flexibility in application. 19 Angle4 comes with many new options, bringing brand new functionalities which make working with Angle easier. The most important new features are briefly highlighted as follows.…”

“…Angle4 comes with a set of eight predefined demo detectors, one for each supported type. 19 Demo detectors can be used for calculations even in demo mode, that is, even if Angle is not registered. This enables the users to run calculations and evaluate the results, so as to become more familiar with the scope and capabilities of the software without/before being registered.…”

“…It shows both the calculated efficiencies for selected energies and the fitted efficiency curve, together with the reference efficiency curve. 19 It is now also possible to import parameters for detectors, containers, geometries, reference efficiency curves and energies from calculation parameter files and calculation results files. Additionally, now it is possible to export the results to ORTEC GammaVision -both to efficiency calibration (EFT) and geometry correction (GEO) files.…”

“…The report contains both the results and all the input parameter data used in calculations. 19 This makes the results traceable to the input values. Command line parameters.…”

Using Mathematical Procedure to Compute the Attenuation Coefficient in Spectrometry Fields

“…Based on the direct mathematical method [10][11][12][13][14][15][16][17], a new theoretical approach was introduced to determine the detector ef iciency by the use of isotropic radiating axialpoint sources located at different heights from the cylindrical detector upper surface. This method depends on the accurate analytical calculation of the average path length covered by the photon inside the detector active volume and the effective solid angle Ω eff .…”