Computer Model Generated Density Correction Factors for Gamma Spectroscopy Counting

1997 ◽  
Vol 72 (2) ◽  
pp. 313-317 ◽  
Author(s):  
Joseph J. Darman ◽  
John P. Aldana
2020 ◽  
Vol 23 (4) ◽  
pp. 374-385
Author(s):  
V. Kalinnikov ◽  
E. Velicheva ◽  
A. Grabtchikov ◽  
I. Khodasevich ◽  
V. Orlovich ◽  
...  

The distribution of the light yield and luminescence intensity along LYSO:Ce crystal length is investigated. These distributions, determined by different defects and emission centers of the dopant in the crystalline structure and its distribution along the length, is measured by two methods: the gamma spectroscopy using radiation sources and the optical spectroscopy using ultraviolet sources. It is shown that crystals have considerable variation of the light yield and luminescence intensity both over the length of an individual crystal (in the growing direction) and for different crystals. It is established that the correction factors for the segmented calorimeter of the COMET experiment can be obtained using optical spectroscopy methods. Consideration of the correction factors will significantly reduce an error of energy measurement in a segmented calorimeter during data handling.


2021 ◽  
Vol 240 ◽  
pp. 03002
Author(s):  
Jawaher Al-Tuweity ◽  
Hassan Kamleh ◽  
M. Said Al-Masri ◽  
A. Wael Doubal ◽  
El Mahjoub Chakir

This study aimed to determine the self-absorption correction factors of lead-210 (210Pb) in various Syrian environment samples. Seven sediments, five soils, and four plant samples were analysed by Gamma Spectroscopy using simple and direct analysis method called Cutshall. The method is based on measuring the penetration of gamma which emitted from a standard source, prepared in the laboratory by deposition of QCYB40 Standard Solution on stainless steel disk. The source was placed on top of the studied sample and the reference air sample during the measurement. The purpose was to study the self-absorption inside each sample by calculation of its self-absorption factors without knowing its chemical composition. The self-absorption correction results for the sediment samples SE3, SE6 and SE8 ranged between 36% and 45%, and 34% to 42% for the soil samples S5 and S1, respectively. Also, for the four plant samples, it recorded variance range from 4% to 18%. This is due to the difference in the density of the G4 sample, which appeared to be very low. However, the self-absorption correction factors CF were set for the different environmental samples, and the results show that the density factor of the sample is not the only influent factor in the CF values for low energies measurement, the sample chemical composition (sample matrix) is also more effective in addition to the samples’ particle sizes.


2021 ◽  
Vol 234 ◽  
pp. 00051 ◽  
Author(s):  
Jawaher Al-Tuweity ◽  
Hassan Kamleh ◽  
M. Said Al-Masri ◽  
A.Wael Doubal ◽  
Azougagh Mohamed ◽  
...  

In environment radiation measurement, calculation the correction factors are critical, especially for low energy measurement because of self-absorption phenomena. In this work the main purpose is to determination the self-absorption correction factors of lead-210 (210Pb) energy (46.5keV) in various environment samples (7 sediments, 5 soil) using an experimental method called Spike Method. The samples were collecting from different places in Syrian. They were prepared according to the laboratory producers starting from collecting, cleaning, drying, grounding, hemogenic and calculating the appearance density. Low-energy gamma spectroscopy HPGe was used for radiation analysis which available at the laboratories of the Protection and Safety Department - Syrian Atomic Energy Commission – Syria. The spike method depends on adding a quantity of a standard solution with a known activity which contains lead isotope 210Pb and added to the studied samples. Self-absorption correction factors (CF) calculated by the ratio of the count rate or activity of spiked and unspiked samples. The CF for sediment samples were between 29% to 54% and for soil samples, the CFs were between 38% to 56% recording correction higher than sediment samples. The results showed a relatively high self-absorption and CFs values because of the chemical composition changeable between the spiked and unspiked samples. For that, it is better to adopt other methods less expensive, give results faster, higher accuracy and do not make change in the chemical composition. The results were also showed the density factor is the most influential factor in self-absorption phenomena.


2004 ◽  
Vol 171 (4S) ◽  
pp. 420-420
Author(s):  
Sijo J. Parekattil ◽  
Paul Shin ◽  
Anthony J. Thomas ◽  
Ashok Agarwal
Keyword(s):  

1997 ◽  
Vol 36 (04/05) ◽  
pp. 237-240
Author(s):  
P. Hammer ◽  
D. Litvack ◽  
J. P. Saul

Abstract:A computer model of cardiovascular control has been developed based on the response characteristics of cardiovascular control components derived from experiments in animals and humans. Results from the model were compared to those obtained experimentally in humans, and the similarities and differences were used to identify both the strengths and inadequacies of the concepts used to form the model. Findings were confirmatory of some concepts but contrary to some which are firmly held in the literature, indicating that understanding the complexity of cardiovascular control probably requires a combination of experiments and computer models which integrate multiple systems and allow for determination of sufficiency and necessity.


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