scholarly journals Detection Efficiency of a NaI (Tl) Gamma Spectrometry System for Measurement of Low Level Radioactivity

2021 ◽  
pp. 61-65
Author(s):  
Biere Ebibuloami ◽  
Ogunremi Ayorinde ◽  
Aina Oluwagbenga ◽  
Emumejaye Kugbere ◽  
Olaoye Adeola ◽  
...  
Keyword(s):  
Gamma Spectrometry ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Detection System ◽  
Counting Efficiency ◽  
Energy Agency ◽  
Detector Resolution ◽  
Gamma Ray Spectrometer ◽  
Energy Peak

Qualitative analysis of radionuclides requires the use of reliable gamma-ray detection system. The NaI(Tl) detector has been widely used and still one of the most used detectors today. It is therefore imperative to validate the reliability of the 5x5 cm2 NaI(Tl) gamma spectrometry system used in carrying out gamma-ray analysis of soil samples in the Radiation and Health Laboratory, Federal University of Agriculture Abeokuta, Nigeria. The gamma ray spectrometer is housed in a 5 cm thick cylindrical lead shield. Calibration was executed using standard materials produced under the auspices of the International Atomic Energy Agency (IAEA). Resolution and detection limit (LD) of the detector were determined using full width at half the maximum of the energy peak of 137Cs and background signal level of the reference materials respectively. Counting efficiencies of the detector was calculated using energies of 1460 keV, 1764keV and 2615 keV for 40K, 226Ra and 232Th respectively. Secondary samples, RGMIX1 and RGMIX2 were formulated and counted to calculate activity concentrations using the NaI(Tl) detector. Resolution of the detector was calculated to be 7.8% of 137Cs, which is good for a NaI(Tl) detector. The counting efficiency of the detector is seen to depend on the gamma ray energy. The results from this work shows that the detector system is suitable gamma spectrometry, and will give quality measurements when used for quantitative determination of radionuclides in environmental samples. The efficiency and resolution of the NaI(Tl) detector should also be determined using photon energies obtained from other radioactive sources.

scholarly journals Progress in radionuclide characterisation in marine sediments using an underwater gamma-ray spectrometer in 2π geometry

2019 ◽  
Vol 21 ◽  
pp. 29
Author(s):  
E. G. Androulakaki ◽  
C. Tsabaris ◽  
M. Kokkoris ◽  
G. Eleftheriou ◽  
D. L. Patiris ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detection System ◽  
Full Energy Peak ◽  
Gamma Ray Spectrometry ◽  
Peak Efficiency ◽  
Full Energy ◽  
Effective Manner ◽  
Energy Peak ◽  
Full Energy Peak Efficiency

The in-situ gamma-ray spectrometry is a well suited method for seabed mapping applications, since it provides rapid results in a cost effective manner. Moreover, the in-situ method is preferable to the commonly applied laboratory measurements, due to its beneficial characteristics. Therefore, the development of in-situ systems for seabed measurements continuously grows. However, an efficiency calibration of the detection system is necessary for obtaining quantitative results in the full spectral range. In the present work, an approach for calculating the full-energy peak efficiency of an underwater insitu spectrometer for measure- ments on the seabed is presented. The experimental work was performed at the coastal site of Vasilikos (Cyprus). The experimental full-energy peak efficiency of the in-situ was determined in the energy range 1400–2600 keV, by combining the in-situ and laboratory reference measurements. The experimental effi- ciency results were theoretically reproduced by means of Monte Carlo (MC) simulations, using the MCNP5 code.

Threshold Radioactivity for Bulk Food Samples by Gamma Spectroscopy

1965 ◽  
Vol 48 (1) ◽  
pp. 1-5
Author(s):  
Harry M Yakabe ◽  
Hiram Neilson
Keyword(s):  
Gamma Ray ◽  
Gamma Spectroscopy ◽  
Rapid Determination ◽  
Detection System ◽  
Fission Products ◽  
Food Samples ◽  
Family Of Curves ◽  
Lower Limits ◽  
True Activity

Abstract In the surveillance of bulk food produce by gamma ray spectroscopy for fission products, the activities of the commonly observed radionuclides are frequently in the magnitude of background inherent to the detection system. The problems of determining whether the sample is in fact contaminated, the lower limits of detecting the radionuclides, and the effect of compton smear on the lower limits are discussed. The discussions are based on the modified spectrum stripping method for quantitative analysis of gamma ray spectrum for the following radioisotopes: Cs-137, Zr-95/Nb-95, and K-40. A family of curves are shown for rapid determination of the minimum detectable true activity (AII) of Cs-137.

Uncertainty Analysis of Activity Measurement of New Monitoring System for Free-Release for NPP A-1 Decommissioning, Slovakia

2011 ◽  
Author(s):  
Alojz Slaninka ◽  
Ondrej Sla´vik ◽  
Vladimi´r Necˇas
Keyword(s):  
Uncertainty Analysis ◽  
Monitoring System ◽  
Detection Efficiency ◽  
Activity Measurement ◽  
Counting Geometry ◽  
Rectangular Container ◽  
Energy Peak ◽  
Hpge Detectors ◽  
Detector Characterization

New free release monitoring post with a large volume 600 L container counting geometry was designed and developed. The monitoring system is able to monitor a material also in standard counting geometry of 200 L drum. Using counting geometry of 600 L rectangular container that is equipped with self-discharger is able to increase the total monitoring capacity. The monitoring system is based on a pair of electrically cooled semiconductor HPGe detectors that are placed into a modifiable vertical or horizontal pair of lead collimators. The monitoring system is integrated with an industrial scale for determination of massic activities of measured materials and in addition by a rotating table in the case of 200 L drums monitoring. Monitoring system is integrated into transportable ISO container with constant environmental conditions that are ensured by air-condition unit. Full-energy peak detection efficiency (FPE) polynomial curves for various densities of measured material were in both cases determined by ISOCS calibration code based on designed counting geometry and delivered ISOCS/LabSOCS detector characterization. Uncertainty analysis of massic activity measurement by container and drum monitoring system in designed counting geometry is introduced below in more detail.

Development of a fast characterization setup for radionuclide generators demonstrated by a 227Ac-based generator

2021 ◽  
Vol 109 (3) ◽  
pp. 205-214
Author(s):  
Dominik Krupp ◽  
Christoph E. Düllmann ◽  
Lotte Lens ◽  
Ulrich W. Scherer
Keyword(s):  
Hydrochloric Acid ◽  
Gamma Ray ◽  
Detection System ◽  
Cation Exchange Resin ◽  
Counting Efficiency ◽  
Gamma Ray Spectrometry ◽  
Pressure Oscillations ◽  
Generator Column ◽  
3D Printed

Abstract The development of a setup for a fast online characterization of radionuclide generators is reported. A generator utilizing the mother nuclide 227Ac sorbed on a cation exchange resin is continuously eluted by using a peristaltic pump. To allow continuous and pulse-free elution of a large volume over extended time periods a 3D-printed interface designed to remove pressure-oscillations induced by the pump was placed between pump and generator column to ensure undisturbed generator elution. The eluate of the generator is passed through a 3D printed flow cell placed inside a borehole Na(Tl)-scintillation detector for high counting efficiency. Alternatively, a HPGe detector suitable for nuclide identification was used to demonstrate the validity of the online method. The detection system combines conventional gamma-ray spectrometry with fast list mode data acquisition in the Matlab software package. Elution experiments were performed at different flow rates of hydrochloric acid, separating 211Bi (t 1/2 = 2.14 min) free from its parent nuclides. In addition, to prove the versatility of the setup, experiments at different hydrochloric acid concentrations were performed resulting in the elution of pure 211Pb (t 1/2 = 36.1 min) and 223Ra (t 1/2 = 11.43 d), respectively.

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