A practical method for determining γ-ray full-energy peak efficiency considering coincidence-summing and self-absorption corrections for the measurement of environmental samples after the Fukushima reactor accident

Author(s):  
Kiyoshi Shizuma ◽  
Yurika Oba ◽  
Momo Takada
1965 ◽  
Vol 43 (7) ◽  
pp. 1173-1181 ◽  
Author(s):  
H. L. Malm ◽  
A. J. Tavendale ◽  
I. L. Fowler

A high-resolution, germanium p-i-n diode gamma-ray spectrometer has been made using the coaxial method of lithium drift. The detector described is ~ 16 cm3 in sensitive volume, three to four times that of the largest "planar" drifted diodes of this type described to date. Its performance as a spectrometer is comparable with that of smaller diodes; resolutions (fwhm) of 3.3 and 4.8 keV were obtained at γ-ray energies of 122 and 1 333 keV respectively with a detector bias of 1 000 to 1 500 V. Typical γ-ray spectra obtained with sources of 57Co, 60Co, 137Cs, and Th(B + C + C″) are shown. Also shown are curves of intrinsic full-energy peak efficiency over a range of energies. This efficiency is 2.5% at 1 300-keV γ-ray energy—comparable to that of a NaI scintillation spectrometer 1 in. in diameter by 1 in. long.


2019 ◽  
Vol 54 (2) ◽  
pp. 133-140
Author(s):  
W. Khan ◽  
C. He ◽  
Y. Cao

A detailed study of the full energy peak efficiency of a high purity germanium (HPGe) detector including the effect of source self-absorption and coincidence summing was performed using Monte Carlo simulation, as it is difficult and time-consuming to measure the full energy peak efficiency experimentally. Cylindrical water composition source was simulated with different characteristics, covering the energy range from 60 to 1836 keV. Self-absorption correction factors (SAFcal) were calculated for two source volumes and obtained good agreement with the experimental results except for (60Co and 88Y) nuclides. The simulation was performed for various samples with different densities and observed their effects on the full energy peak efficiency value of the detector. In the case of extended volumetric source, the coincidence summing correction factors (CSFcal) for two nuclides (60Co and 88Y) were estimated with the GEANT4 simulation toolkit. The effect of correction factors on different cylindrical source volumes was also investigated. With the self-absorption and coincidence summing effect, the best agreement was achieved between simulated and experimental results with discrepancy less than 2% for all of the radionuclides included in two source volumes.


2017 ◽  
Vol 55 (2) ◽  
pp. 478-489 ◽  
Author(s):  
Ahmed M. El-Khatib ◽  
Bohaysa A. Salem ◽  
Mohamed S. Badawi ◽  
Mona M. Gouda ◽  
Abouzeid A. Thabet ◽  
...  

2019 ◽  
Vol 21 ◽  
pp. 29
Author(s):  
E. G. Androulakaki ◽  
C. Tsabaris ◽  
M. Kokkoris ◽  
G. Eleftheriou ◽  
D. L. Patiris ◽  
...  

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.


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