Determination of Full Energy Peak Efficiency of NaI(Tl) Detector Depending on Efficiency Transfer Principle for Conversion Form Experimental Values

Abd-Elzaher, Mohamed; Badawi, Mohamed S.; El‐Khatib, Ahmed M.; Thabet, Abouzeid Ahmed

doi:10.4236/wjnst.2012.23011

Cited by 25 publications

(11 citation statements)

References 9 publications

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“…The signals from the detector were amplified and analyzed with an 8K multichannel analyzer. The efficiency of the NaI (Tl) detector is higher at low source energy (26). The Low-Z samples such as sodium thiosulfate (Na 2 S 2 O 3 ), benzoic acid (C 7 H 6 O 2 ), sodium hydroxide (NaOH), poly vinyl alcohol (PVA) (C 2 H 4 O), potassium nitrate(KNO3), naphthalene (C 10 H 8 ) using KBr press machine pellets were prepared having the same thickness.…”

Section: Methodsmentioning

confidence: 99%

Effects of gamma irradiation on some chemicals using an NaI (Tl) detector

Bhosale

Gaikwad

Pawar

et al. 2016

Radiation Effects and Defects in Solids

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The present work was carried out to find out the gamma ray shielding properties and to study the effects using an NaI (Tl) detector using radioactive sources 57 Co, 133 Ba, 137 Cs, 54 Mn, 60 Co and 22 Na at energies 122, 356, 511, 662, 840, 1170, 1275 and 1330 keV, for some chemicals, namely, sodium thiosulfate (Na 2 S 2 O 3 ), benzoic acid (C 7 H 6 O 2 ), sodium hydroxide (NaOH), poly vinyl alcohol (PVA) (C 2 H 4 O), potassium nitrate (KNO3), naphthalene (C 10 H 8 ). Mass attenuation coefficient (µ m ) values obtained from the experiment were used to determine the effective atomic numbers (Z eff ) and effective electron densities (N eff ), atomic cross-sections (σ t ) and electronic cross-sections (σ e ); it will be observed from the present work that the variation in the obtained values is only due to the increase or decrease in the gamma ray energy and the chemical composition of the sample. It was seen that the calculated and obtained values showed good agreement. The investigated data are useful in the electronic industry, plastic industry, building materials and agriculture fields. From the present work it was found that the PVA could be used as a better gamma shielding material. ARTICLE HISTORY

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Section: Methodsmentioning

confidence: 99%

Effects of gamma irradiation on some chemicals using an NaI (Tl) detector

Bhosale

Gaikwad

Pawar

et al. 2016

Radiation Effects and Defects in Solids

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show abstract

“…To reduce the background radiation, the inner parts of the detector were surrounded by Pb shielding, as shown in Figure 1(b). This geometry was adapted from Abd-Elzaher, et al [25].…”

Section: Methodsmentioning

confidence: 99%

Simulation of Void Detection System using Gamma-Ray Compton Scattering Technique

Sari

Wirawan

Waris

et al. 2019

J. Eng. Technol. Sci.

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A simple void detection system for concrete was successfully developed using high-penetration gamma rays with Compton scattering. This research attempted to identify a void in the subsurface of a concrete volume that could not be accessed from any of the sides. Monte Carlo simulation using GEANT4 toolkit was performed to investigate the gamma-ray backscattering events. An NaI(Tl) detector was used with 60 Co and 137 Cs as gamma-ray sources. The void's location was successfully detected during material target scanning. Density discrepancies conduce variance of the backscattering peak produced due to the presence of a void. Compared to 60 Co as the gamma-ray source, 137 Cs is a better choice for application in NDT systems using Compton scattering.

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“…This is likely because the NaI-efficiency decreases smoothly with energy for energies greater than 120 keV. 30 If additional data points were measured at energies below 120 keV, a function with more than two parameters might be necessary to accurately describe the efficiency of the thyroid-probe.…”

Section: A1 Thyroid-probe Efficiency Curvementioning

confidence: 99%

Accuracy, reproducibility, and uncertainty analysis of thyroid‐probe‐based activity measurements for determination of dose calibrator settings

et al. 2016

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Purpose: In the nuclear medicine department, the activity of radiopharmaceuticals is measured using dose calibrators (DCs) prior to patient injection. The DC consists of an ionization chamber that measures current generated by ionizing radiation (emitted from the radiotracer). In order to obtain an activity reading, the current is converted into units of activity by applying an appropriate calibration factor (also referred to as DC dial setting). Accurate determination of DC dial settings is crucial to ensure that patients receive the appropriate dose in diagnostic scans or radionuclide therapies. The goals of this study were (1) to describe a practical method to experimentally determine dose calibrator settings using a thyroid-probe (TP) and (2) to investigate the accuracy, reproducibility, and uncertainties of the method. As an illustration, the TP method was applied to determine 188 Re dial settings for two dose calibrator models: Atomlab 100plus and Capintec CRC-55tR. Methods: Using the TP to determine dose calibrator settings involved three measurements. First, the energy-dependent efficiency of the TP was determined from energy spectra measurements of two calibration sources ( 152 Eu and 22 Na). Second, the gamma emissions from the investigated isotope ( 188 Re) were measured using the TP and its activity was determined using γ-ray spectroscopy methods. Ambient background, scatter, and source-geometry corrections were applied during the efficiency and activity determination steps. Third, the TP-based 188 Re activity was used to determine the dose calibrator settings following the calibration curve method [B. E. Zimmerman et al., J. Nucl. Med. 40, 1508Med. 40, -1516Med. 40, (1999]. The interobserver reproducibility of TP measurements was determined by the coefficient of variation (COV) and uncertainties associated to each step of the measuring process were estimated. The accuracy of activity measurements using the proposed method was evaluated by comparing the TP activity estimates of 99m Tc, 188 Re, 131 I, and 57 Co samples to high purity Ge (HPGe) γ-ray spectroscopy measurements. Results: The experimental 188 Re dial settings determined with the TP were 76.5 ± 4.8 and 646 ± 43 for Atomlab 100plus and Capintec CRC-55tR, respectively. In the case of Atomlab 100plus, the TP-based dial settings improved the accuracy of 188 Re activity measurements (confirmed by HPGe measurements) as compared to manufacturer-recommended settings. For Capintec CRC-55tR, the TP-based settings were in agreement with previous results [B. E. Zimmerman et al., J. Nucl. Med. 40, 1508Med. 40, -1516Med. 40, (1999] which demonstrated that manufacturer-recommended settings overestimate 188 Re activity by more than 20%. The largest source of uncertainty in the experimentally determined dial settings was due to the application of a geometry correction factor, followed by the uncertainty of the scatter-corrected photopeak counts and the uncertainty of the TP efficiency calibration experiment. When using the most intense pho...

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Determination of Full Energy Peak Efficiency of NaI(Tl) Detector Depending on Efficiency Transfer Principle for Conversion Form Experimental Values

Cited by 25 publications

References 9 publications

Effects of gamma irradiation on some chemicals using an NaI (Tl) detector

Effects of gamma irradiation on some chemicals using an NaI (Tl) detector

Simulation of Void Detection System using Gamma-Ray Compton Scattering Technique

Accuracy, reproducibility, and uncertainty analysis of thyroid‐probe‐based activity measurements for determination of dose calibrator settings

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