Using standard calibrated geometries to characterize a coaxial high purity germanium gamma detector for Monte Carlo simulations

2014 ◽  
Vol 85 (6) ◽  
pp. 065110
Author(s):  
E. R. van der Graaf ◽  
P. Dendooven ◽  
S. Brandenburg
2020 ◽  
Vol 17 (1) ◽  
pp. 15
Author(s):  
Sedigheh Sina ◽  
Zahra Molaeimanesh ◽  
Mehrnoosh Karimipoorfard ◽  
Zeinab Shafahi ◽  
Maryam Papie ◽  
...  

The virtual point detector concept is useful in gamma-ray spectroscopy. In this study, the virtual point detector, h0, was obtained for High Purity Germanium (HPGe) detectors of different sizes using MCNP5 Monte Carlo simulations. The HPGe detectors with different radii (rd), and height (hd), having aluminum, or Carbon windows, were simulated. A point photon source emitting several gammas with specific energies was defined at a distance x of the detectors. The pulse height distribution was scored using F8 tally. Finally, the artificial neural network was used for predicting the h0 values for every value of hd, rd, and x. Because of the high simulation duration of MCNP code, a trained ANN is used to predict the value of h0 for each detector size. The results indicate that the Artificial Neural Network (ANN) can predict the virtual point detector good accuracy. 


2019 ◽  
Vol 21 ◽  
pp. 129
Author(s):  
N. Patronis ◽  
V. Tsamis ◽  
K. Stamoulis ◽  
K. G. Ioannides

The Canberra BE3825 Broad Energy High Purity Germanium Detector facilitates the detection of -rays from a few keV up to the MeV energy region. Phenomena like self-attenuation and/or coincidence summing e↵ects are hindering the detection of low energy gamma-rays in those cases where extended sources, particu- larly high volume sources are considered. In order to make corrections accordingly, the full characterisation of the HPGe detector is needed. In the present work the Geant4 modeling of the University of Ioannina BE3825 HPGe -ray measuring station is described. The Monte Carlo simulation results are compared with the experimental eciency curves at two di↵erent source to detector distances. In both cases excellent agreement with the experimental results was obtained.


2016 ◽  
Vol 44 ◽  
pp. 1660225
Author(s):  
Mirela Angela Saizu

The developments of high-purity germanium detectors match very well the requirements of the in-vivo human body measurements regarding the gamma energy ranges of the radionuclides intended to be measured, the shape of the extended radioactive sources, and the measurement geometries. The Whole Body Counter (WBC) from IFIN-HH is based on an “over-square” high-purity germanium detector (HPGe) to perform accurate measurements of the incorporated radionuclides emitting X and gamma rays in the energy range of 10 keV–1500 keV, under conditions of good shielding, suitable collimation, and calibration. As an alternative to the experimental efficiency calibration method consisting of using reference calibration sources with gamma energy lines that cover all the considered energy range, it is proposed to use the Monte Carlo method for the efficiency calibration of the WBC using the radiation transport code MCNP5. The HPGe detector was modelled and the gamma energy lines of [Formula: see text]Am, [Formula: see text]Co, [Formula: see text]Ba, [Formula: see text]Cs, [Formula: see text]Co, and [Formula: see text]Eu were simulated in order to obtain the virtual efficiency calibration curve of the WBC. The Monte Carlo method was validated by comparing the simulated results with the experimental measurements using point-like sources. For their optimum matching, the impact of the variation of the front dead layer thickness and of the detector photon absorbing layers materials on the HPGe detector efficiency was studied, and the detector’s model was refined. In order to perform the WBC efficiency calibration for realistic people monitoring, more numerical calculations were generated simulating extended sources of specific shape according to the standard man characteristics.


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