Analytical formulae for borehole scintillation detectors efficiency calibration

Abbas, Mahmoud I.

doi:10.1016/j.nima.2010.06.241

Cited by 17 publications

(14 citation statements)

References 21 publications

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“…In this case, the total and the full-energy peak efficiencies of the well-type detectors must be known as a function of the photon energy and as a function of space vector inside the source volume as well. In order to calculate the both efficiencies for using volumetric sources measured inside the cavity of the well-type NaI(Tl) detectors, equations (11) and (12) are used based on the direct mathematical method [20][21][22][24][25][26] and the efficiency transfer method (ET). [29][30][31] In order to use the efficiency transfer technique (ET), the fitting curve for the measured reference efficiency ε ref must be as essentially done, [29][30][31] which represents 152 Eu radioactive point source and was kept fixed at 50 cm in the measurement geometry from the detector outer end cap as shown in Figure. 5 for both detectors.…”

Section: Resultsmentioning

confidence: 99%

“…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.…”

Section: A Total and Full-energy Peak Efficienciesmentioning

confidence: 99%

“…[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.…”

Section: A Total and Full-energy Peak Efficienciesmentioning

confidence: 99%

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

et al. 2017

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The 4π NaI(Tl) γ-ray detectors are consisted of the well cavity with cylindrical cross section, and the enclosing geometry of measurements with large detection angle. This leads to exceptionally high efficiency level and a significant coincidence summing effect, much more than a single cylindrical or coaxial detector especially in very low activity measurements. In the present work, the detection effective solid angle in addition to both full-energy peak and total efficiencies of well-type detectors, were mainly calculated by the new numerical simulation method (NSM) and ANGLE4 software. To obtain the coincidence summing correction factors through the previously mentioned methods, the simulation of the coincident emission of photons was modeled mathematically, based on the analytical equations and complex integrations over the radioactive volumetric sources including the self-attenuation factor. The measured full-energy peak efficiencies and correction factors were done by using 152Eu, where an exact adjustment is required for the detector efficiency curve, because neglecting the coincidence summing effect can make the results inconsistent with the whole. These phenomena, in general due to the efficiency calibration process and the coincidence summing corrections, appear jointly. The full-energy peak and the total efficiencies from the two methods typically agree with discrepancy 10%. The discrepancy between the simulation, ANGLE4 and measured full-energy peak after corrections for the coincidence summing effect was on the average, while not exceeding 14%. Therefore, this technique can be easily applied in establishing the efficiency calibration curves of well-type detectors.

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Section: Resultsmentioning

confidence: 99%

Section: A Total and Full-energy Peak Efficienciesmentioning

confidence: 99%

Section: A Total and Full-energy Peak Efficienciesmentioning

confidence: 99%

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

et al. 2017

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“…Direct mathematical method to calculate the efficiency of radioactive systems was first proposed by Selim and Abbas and then it was used by several authors [1][2][3][4][5][6][7][8][9][10][11][12]. The comparison between the calculated values of efficiencies and experimental ones provided in these papers shows that the error is very small.…”

Section: Introductionmentioning

confidence: 99%

New Analytical Formulae to Calibrate Well-type Scintillation Detectors Efficiency

Mi¹,

Oa²,

Ibrahim³

et al. 2016

J Phys Math

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Direct Mathematical calculations for the absolute efficiency of well-type gamma ray scintillation crystals are described. Calculated detection efficiencies are drawn for two commonly used well crystals. Comparisons are made between present works and published Monte Carlo values. The present approach proved quite success in predicting the efficiency of well type detectors providing only the geometry and materials of the system formed of source, detector and shielding as well as the energy of the emitted photons.

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“…Most of the authors report agreement with experimentally obtained efficiency values within 10%. One useful way to stun these complications is the use of the straightforward direct mathematical method [4][5][6][7][8][9][10][11][12][13][14][15][16][17] and the experimental measurements. For the polar ( ) and azimuthal ( ) angles, the azimuthal angle, , earns the values from 0 to 2 , while the polar angle, ( ), earns four different values built on the source-to-detector configuration.…”

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confidence: 99%

Calibration of the Absolute Efficiency of Well-Type NaI(Tl) Scintillation Detector in 0.121–1.408 MeV Energy Range

Oraini

2018

Science and Technology of Nuclear Installations

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Well-type NaI(Tl) detectors are beneficial for low-level photon activity measurements because of the near 4 solid angle that can be gained with them. The detection efficiency can differ with the source-to-detector system geometries, the absorption of the photon in the detector material, and attenuation layers in front of the detector face. For these purposes, the absolute efficiency and the coincidence corrections of the well-type sodium iodide detector have been measured at 0.121-1.408 MeV energy range (obtained from 152 Eu, 137 Cs, and 60 Co radioactive isotopes). The covenant between the experimental (present work) and the published theoretical values is good, with the high discrepancies being less than 1%. Theoretical ViewpointIn the case where an isotropic radiating axial point source is in the detector well-cavity at a distance, ℎ, from cavity bottom (see Figure 1), the path of the photon is well defined by the geometrical solid angle, Ω, subtended by the source-to-detector system at the point of entry. The solid angle is given asThe usage of well-type gamma spectrometry systems is useful for low-level gamma activity measurements. To measure the sample's activity, the photopeak efficiency (FEPE) of the detector for each photon energy is needed. This is usually obtained by the efficiency calibration by the use of standard radioactive sources of identical geometrical shape and dimensions with the samples under study [1]. However, the MC simulations consider the detailed characteristics of the source-to-detector system in calculating the photopeak efficiency. This approach (MC) is inadequate in its accuracy because of the inaccuracy in the parameters accompanying the detector's geometrical dimensions and the structure of the sample [2]. The accuracy is also affected by the uncertainty in nuclear data and the calculation uncertainties of the MC code [3], but these are likely to be as important as the parameters linked with the detector's geometrical dimensions and the material composition of the sample. The physical dimensions provided by suppliers are usually unsatisfactory for accurate efficiency calculations because any slight change in some of these geometrical parameters can cause significant deviations from experimental values. Several studies of the response of -ray spectrometers using MC simulations have been published. Most of the authors report agreement with experimentally obtained efficiency values within 10%. One useful way to stun these complications is the use of the straightforward direct mathematical method [4][5][6][7][8][9][10][11][12][13][14][15][16][17] and the experimental measurements. For the polar ( ) and azimuthal ( ) angles, the azimuthal angle, , earns the values from 0 to 2 , while the polar angle, ( ), earns four different values built on the source-to-detector configuration.

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Analytical formulae for borehole scintillation detectors efficiency calibration

Cited by 17 publications

References 21 publications

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

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

New Analytical Formulae to Calibrate Well-type Scintillation Detectors Efficiency

Calibration of the Absolute Efficiency of Well-Type NaI(Tl) Scintillation Detector in 0.121–1.408 MeV Energy Range

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