UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-22 2:13
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Conference: Bucharest University Faculty of Physics 2024 Meeting


Section: Nuclear and Elementary Particles Physics


Title:
A Novel Method for Computing the Full-Energy Peak Efficiency of Coaxial High-Purity Germanium Detectors for Cylindrical Sources


Authors:
D. GURAU(1), D. STANGA(1*), L. DONE(1), O. SIMA(1,2), G. ILIE(3)


Affiliation:
1) National Institute of R&D for Physics and Nuclear Engineering-Horia Hulubei (IFIN-HH)-Romania

2) University of Bucharest, Physics Department, Bucharest-Magurele, P. O. Box MG-12

3) Mirion Technologies, 800 Research Parkway, Meriden, CT 06450, USA



E-mail
doru@nipne.ro


Keywords:
gamma spectrometry, full-energy peak efficiency, computational method, Matlab code


Abstract:
Computed values of the full-energy peak (FEP) efficiency are widely used in gamma spectrometry measurements because the relative method of measurement has severe restrictions. Monte Carlo (MC) simulation codes are often used for computing the FEP efficiency but they are rather complicated, time consuming and require skilled people for their use and the calibration of the detector model. The deterministic codes, are usually simpler and faster than MC simulation codes providing sufficiently accurate values of the FEP efficiency. In many cases, it is more convenient the use of deterministic codes, especially when the sample geometry is poorly known. In this work a simple and fast method was developed to compute the FEP efficiency of coaxial HPGe detectors for cylindrical sources measured by gamma spectrometry laboratories. It is based on an integral expression for computing the FEP efficiency via computing the detector responses and the attenuation factors of point sources embedded in the source matrix. The detector response was computed using the grid based linear interpolation and the FEP efficiency response in grid points was computed using a MC simulation code with a properly calibrated detector model. The attenuation factor was computed using MC integration and the FEP efficiency for cylindrical sources was computed according to the integral expression mentioned above using numerical integration. The method was implemented as a Matlab code, which was written for computing the FEP eficiency of a Canberra detector model GC3018. The Matlab code was extensively verified by intercomparisons with GESPECOR code to evaluate the intrinsic errors of the method and LabSOCS code. In both intercomparisons, the Matlab code provided satisfactory results with the average and the maximum absolute values of the relative deviations between its results and the results of the other two codes smaller than 2 % and 9.5 %, respectively.


References:

1. O. Sima and D. Arnold, On the Monte Carlo simulation of HPGe gamma-spectrometry systems, Applied Radiation and Isotopes 67, 701–705 (2009).

2. D. Gurau, D. Stanga, L. Done, O. Sima, G. Ilie, Calibrating GESPECOR model of computing the full-energy peak efficiency of coaxial high-purity germanium detectors by Monte Carlo simulation, Applied Radiation and Isotopes 204, 111135 (2024).

3. D. Gurau, D. Stanga, L. Done, O. Sima, E. Ionescu, Computational Characterization of coaxial HPGe detectors using Monte Carlo simulation and nonlinear least squares optimization, Romanian Reports in Physics 75, 806 (2023).

4. D. Stanga and D.Gurau, Novel integral expressions for computing the full energy peak efficiency of gamma spectrometry systems, Applied. Radiation and Isotopes. 172, 109689 (2021).



Acknowledgement:
This work was supported by CORE/NUCLEU Program within the National Research Development and Innovation Plan 2022-2027, carried out with the support of Management Center of Research, Development and Innovation (CMCDI), project code PN 23-21.