The effect of front edge on efficiency for point and volume source geometries in p-type HPGe detectors
2
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
Monte Carlo (MC) simulations are increasingly being used as an alternative or supplement to the gamma spectrometric method in determining the full energy peak efficiency (FEPE) necessary for radionuclide identification and quantification. The MC method is more advantageous than the experimental method in terms of both cost and time. Experimental calibration with standard sources is difficult, especially for specimens with unusually shaped geometries. However, with MC, efficiency values can be obtained by modeling the geometry as desired without using any calibration source. Modeling the detector with the correct parameters is critical in the MC method. These parameters given to the user by the manufacturer are especially the dimensions of the crystal and its front edge, the thickness of the dead layer, dimensions, and materials of the detector components. This study aimed to investigate the effect of the front edge geometry of the detector crystal on efficiency, so the effect of rounded and sharp modeled front edges on the FEPE was investigated for <300 keV with three different HPGe detectors in point and volume source geometries using PHITS MC code. All results showed that the crystal should be modeled as a rounded edge, especially for gamma-ray energies below 100 keV.
Abstract
Monte Carlo (MC) simulations are increasingly being used as an alternative or supplement to the gamma spectrometric method in determining the full energy peak efficiency (FEPE) necessary for radionuclide identification and quantification. The MC method is more advantageous than the experimental method in terms of both cost and time. Experimental calibration with standard sources is difficult, especially for specimens with unusually shaped geometries. However, with MC, efficiency values can be obtained by modeling the geometry as desired without using any calibration source. Modeling the detector with the correct parameters is critical in the MC method. These parameters given to the user by the manufacturer are especially the dimensions of the crystal and its front edge, the thickness of the dead layer, dimensions, and materials of the detector components. This study aimed to investigate the effect of the front edge geometry of the detector crystal on efficiency, so the effect of rounded and sharp modeled front edges on the FEPE was investigated for <300 keV with three different HPGe detectors in point and volume source geometries using PHITS MC code. All results showed that the crystal should be modeled as a rounded edge, especially for gamma-ray energies below 100 keV.
참고문헌 (13)
- H. Yücel, "Correction methodology for the spectral interfering g-rays overlapping to the analytical peaks used in the analysis of 232Th", Appl. Radiat. Isot, 69, pp.890~897 (2011)
- O. Sima, "Efficiency Calculation of Gamma Detectors by Monte Carlo Methods", Encyclopedia of Analytical Chemistry (2012)
- S. M. Modarresi, "A method for considering the spatial variations of dead layer thickness in HPGe detectors to improve the FEPE calculation of bulky samples", Radiat. Phys. Chem, 130, pp.291~296 (2017)
- G. Gilmore, "Practical Gamma-Ray Spectrometry" (2008), John Wiley and Sons
- J. Gasparro, "Monte Carlo modelling of germanium crystals that are tilted and have rounded front edges", Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip, 594, pp.196~201 (2008)
- M. Je"skovský, "Experimental and Monte Carlo determination of HPGe detector efficiency", J. Radioanal. Nucl. Chem, 322, pp.1863~1869 (2019)
- A. S. Hoover, "Characterization of the virtual point detector effect for coaxial HPGe detectors using Monte Carlo simulation", Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip, 572, pp.839~843 (2007)
- N. C. Díaz, "Improving the trade-offbetween simulation time and accuracy in efficiency calibrations with the code DETEFF", Appl. Radiat. Isot, 68, pp.1413~1417 (2010)
- M. H. B€olükdemir, "Investigation of shape effects and dead layer thicknesses of a coaxial HPGe crystal on detector efficiency by using PHITS Monte Carlo simulation", Radiat. Phys. Chem, 189, pp.109746~ (2021)
- "Preparation and certification of IAEA gamma-ray spectrometry reference materials RGU-1, RGTh-1 and RGK-1, Iaea-Rl-148" (1987)[URL]
- T. Sato, "Features of particle and Heavy Ion transport code system(PHITS)version 3. 02", J. Nucl. Sci. Technol, 55, pp.684~690 (2018)
- E. Uyar, "Investigation of the effect of copper contact pin on efficiency in HPGe detectors using Monte Carlo method", J. Instrum, 16, pp.T11003~ (2021)
- "COM: Photon Cross Section Database"[URL]