STATISTICAL DATA ANALYSIS OF GAMMA-RAY BACKGROUND SPECTRA FOR QUALITY ASSURANCE PURPOSES (original) (raw)
Related papers
Gamma-Ray Spectrometry and the Investigation of Environmental and Food Samples
2017
Gamma radiation consists of high‐energy photons and penetrates matter. This is an advantage for the detection of gamma rays, as gamma spectrometry does not need the elimination of the matrix. The disadvantage is the need of shielding to protect against this radiation. Gamma rays are everywhere: in the atmosphere; gamma nuclides are produced by radiation of the sun; in the Earth, the primordial radioactive nuclides thorium and uranium are sources for gamma and other radiation. The technical enrichment and use of radioisotopes led to the unscrupulously use of radioactive material and to the Cold War, with over 900 bomb tests from 1945 to 1990, combined with global fallout over the northern hemisphere. The friendly use of radiation in medicine and for the production of energy at nuclear power plants (NPPs) has caused further expositions with ionising radiation. This chapter describes in a practical manner the instrumentation for the detection of gamma radiation and some results of the ...
Physics Access, 2021
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 ...
In situ gamma-ray spectrometry: A tutorial for environmental radiation scientists
1993
"This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosedl, or represents that its use would not infringe privately owned rights. Reference herein to any specific commeJ:cial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof."
Low-level gamma-ray spectrometry for environmental samples
Journal of Radioanalytical and Nuclear Chemistry, 2008
Low-level gamma-ray spectrometry with large volume HPGe detectors has been widely used in analysis of environmental radionuclides. The reasons are excellent energy resolution and high efficiency that permits selective and non-destructive analyses of several radionuclides in composite samples. Although the most effective way of increasing the sensitivity of a gamma-ray spectrometer is to increase counting efficiency and the amount of the sample, very often the only possible way is to decrease the detector's background. The typical background components of a low-level HPGe detector, not situated deep underground, are cosmic radiation (cosmic muons, neutrons and activation products), radioactivity of construction materials, radon and its progenies. A review of Monte Carlo simulations of background components of HPGe detectors, and their characteristics in coincidence and anti-Compton mode of operation are presented and discussed.
Applied Radiation and Isotopes, 2010
A computing code based on the CERN's GEANT4 has been used to compute cosmic-ray background components of low-level Ge-spectrometers, optionally equipped with an anticosmic shield made of a plastic scintillation detector. The results show that the background of the Ge detector placed at 100 m w.e. (water equivalent) has decreased by a factor of 30 and 100 without and with anticosmic shielding, respectively, when compared with a surface laboratory without anticosmic shielding.
Nucleus, 2009
The capabilities of the LowBackground Gamma Spectrometer (LBGS) at InSTEC were studied for environmental purposes. Fifty three glines were identified in the LBGS background spectrum. The Minimum Detectable Activity for 210 Pb, 238 U, 226 Ra, 137 Cs, 232 Th and 40 K were calculated using the detector's volumetric efficiency simulated by Monte Carlo method. Validation was performed by absolute and relative analysis of radionuclide activities present in a marine sediment certified material. CARACTERIZACIÓN DEL ESPECTRÓMETRO GAMMA DE BAJO FONDO DEL INSTEC PARA ESTUDIOS DE RADIOACTIVIDAD AMBIENTAL Resumen Se determinan las potencialidades del Espectrómetro Gamma de Bajo Fondo del InSTEC con fines ambientales. Se identificaron 53 líneas gamma en el espectro de fondo natural del espectrómetro. Se calculan las actividades mínimas detectables para los radionucleidos 210 Pb, 238 U, 226 Ra, 137 Cs, 232 Th and 40 K empleando la eficiencia volumétrica del detector simulada por Monte Carlo. Como validación se determinan, por vía absoluta y relativa, las actividades de los radionucleidos presentes en un estándar de sedimento marino.
International Journal of Computer Applications
The paper introduces smoothing method for gamma ray spectra. Motive of this method is to reduce the influence of statistical fluctuations and the random noise. Because of fluctuation, data prohibit for accurate estimation of composition of sample. In this work we have used the laboratory based data obtained from the Gamma Ray Spectrometer (GRS) developed in our laboratory using different scintillation detector like LaBr 3 :Ce/CeBr 3. The digitized data from the developed GRS instrument are readout to computer through a NI DIO (National Instruments Digital Input/Output) card. Data acquisition system has been developed in LabVIEW to generate the gamma spectrum.
Calibration of the High Purity Germanium Gamma-Ray Spectrometer in Cert, Abu Zaria, Nigeria
Modern Instrumentation, 2015
Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. The gamma-ray spectrometer laboratory in Centre for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria is accredited to perform measurements of radioactive content of samples collected from the environment, food chain or industrial products with the aid of a high resolution HPGe detector. For accurate gamma-ray spectrometry, certain measurements were considered; the efficiency of the detector was performed experimentally against energies within the range of 59.50 keV ( 241 Am) to 2204.50 keV ( 226 Ra) for the respective geometries of 1 -6 cm. The sustained solid angle relations with respect to the inverse square of sample geometries from 1 -6 cm were evaluated. Another main point of this work was focused on the efficiency at geometry of 5 cm with respect to the three selected energies: 661.60 keV ( 137 Cs), 1173.2 keV ( 60 Co) and 1332 keV ( 60 Co) for the main axis, ten degree off main axis, forty five degree off main axis and ninety degree off the detector main axis. In order to verify optimum geometries in our laboratory for both short lived and long lived radionuclides analyses, the evaluation of efficiencies for the respective energies: 1173.2 keV ( 60 Co), 1332.5 keV ( 60 Co), 1764 keV ( 226 Ra) and 2294 keV ( 226 Ra) were plotted against geometries of 1 to 6 cm from the detector end cap along the main axis.
Assessment of calibration parameters for gamma-ray spectrometry systems
Journal of Radioanalytical and Nuclear Chemistry, 2011
The Gamma-ray spectrometers are complex instruments and the quality of the data they provide depends strongly on their proper calibration. This paper describes the energy and efficacy calibration of two gamma-ray spectrometers in order to validate the method for measuring the activity of gamma-ray emitting radionuclides. The punctiform standard sources 60 Co, 133 Ba, 137 Cs and 241 Am were used in this study. Minimum Detectable Activity, Peak to Compton Ratio and the peak shape parameters were determinate. An inter-comparison of the results obtained with both systems was done. The results demonstrated that the activity values are comparable with low errors respecting with those for conventionally true activities.