Accurate calculation of well-type detector geometrical efficiency using sources with different shapes and geometries

Abstract

The well-type detectors are widely used to determine the low level activity in small samples, thus the absolute detector efficiency is required. The calculation of the absolute efficiency of well-type HPGe or NaI(Tl) detectors depends mainly on the value of the geometrical efficiency. The geometrical efficiency depends on the solid angle subtended by various sources situated at different locations from the detector surface. The present work is essentially concerned to introduce a numerical simulation method (NSM) to calculate the geometrical efficiency and give the ability to use it in the theoretical calibration process of γ-ray well-type detectors for using isotropic radiating γ-ray (point, disk or volumetric) sources. The results are compared with some published data to show the approach validity and shows how much this work is important in the efficiency calibration process for the complicated γ-ray detection system. KEYWORDS: Models and simulations; Gamma detectors (scintillators, CZT, HPG, HgI etc); Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators); Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc)

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

“…In this section, a new numerical simulation method (NSM) based on the direct method [20][21][22][23][24][25][26][27][28][29][30][31] will be functional to obtain the total and the full-energy peak efficiency of the well-type detector. The well-type detector of outer radius R 2 , cavity radius R 1 , outer height L and cavity depth S will be considered as shown in Figure. 1.…”

“…[29][30][31] The full-energy peak efficiency ε p(Cylinder) of the well-type detectors can be given based on the following equation: [29][30][31] The double integrals in the both methods, the direct mathematical method and the numerical simulation method (NSM) [20][21][22][23][24][25][26][27][28][29][30][31] for the total and the full-energy peak efficiency of the well-type detector can be evaluated numerically using the trapezoidal rule. A computer program has been written in BASIC programming language to evaluate the efficiency of a well-type detector with respect to the source-to-detector separation.…”

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 .…”

“…When chemical composition of the samples is known, this coef icient can be calculated by using the photon cross sections data base [5]. There is one method for determining the linear attenuation coef icient under the assumption that the density of the sample in which a collimated narrow beam is used [6][7][8][9][10] is uniform. However, this method is dif icult to be carried out in a typical laboratory because of high radioactivity of sources prices and the requirement of a large space for the devices.…”

Study Attenuation Parameters and Physical Properties of Silicone Rubber Reinforced with Nano- and Micro-Sized Aluminum Oxide Composites

“…The use of radiation in numerous parts of daily life is no longer something that people can deny [1]. This is due to the widespread usage of radioactive gamma sources in healthcare, agriculture, industry, scientific research, and many other practical sectors [2]. Living organisms that depend on gamma energy face significant risks when exposed to gamma beams [3].…”