EFFECT OF SAMPLE POSITION ON EFFICIENCY IN GAMMA-RAY SPECTROSCOPY

Year 2023, Volume: 36 Issue: 2, 14 - 20, 30.12.2023

Esra Uyar , Mine Özgür , Hasan Dikmen

Abstract

The full energy peak efficiency for the energies of interest must be known to determine the concentration of activity in gamma-ray spectrometry. This work is focused on examining the effect of sample position on full energy peak efficiency. For this purpose, efficiency values were determined by experimental and Monte Carlo simulation method using three different HPGe detectors and standard charcoal cartridges. The cartridges were first counted in the centers of the detectors and then replaced on the X-axis at 5 mm intervals. At maximum distances from the center of 25 mm for Ge-1, 15 mm for Ge-2, and 10 mm for Ge-3, experimental full energy peak values are 11.8-16.4% in Ge-1, 8.2-13.8% in Ge-2, and decrease between 4.9-11.0% in Ge-3. The results show that the sample position significantly affects the full energy peak efficiency, using a sample locator if possible, if not counting as carefully in the center as possible.

Keywords

Gamma-ray spectroscopy, full energy peak efficiency, sample position, charcoal cartridge filter.

References

• References
• Ağuş, Y. (2019). Gamma Spectrometric Efficiency Measurement Uncertainty of 137Cs in the Vegetation Sample. Celal Bayar Üniversitesi Fen Bilimleri Dergisi, 15(1), 51–55. https://doi.org/10.18466/cbayarfbe.455494
• Chuong, H. D., Thanh, T. T., Ngoc Trang, L. T., Nguyen, V. H., & Tao, C. Van. (2016). Estimating thickness of the inner dead-layer of n-type HPGe detector. Applied Radiation and Isotopes, 116, 174–177. https://doi.org/10.1016/j.apradiso.2016.08.010
• Gilmore, G. (2008). Practical Gamma-ray spectrometry (2nd ed.). New York: John Wiley and Sons.
• Guerra, J. G., Rubiano, J. G., Winter, G., Guerra, A. G., Alonso, H., Arnedo, M. A., … Bolivar, J. P. (2017). Computational characterization of HPGe detectors usable for a wide variety of source geometries by using Monte Carlo simulation and a multi-objective evolutionary algorithm. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 858, 113–122. https://doi.org/10.1016/j.nima.2017.02.087
• Gurau, D., Stanga, D., Done, L., Sima, O., & Ilie, G. (2024). 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. https://doi.org/ 10.1016/j.apradiso.2023.111135
• Khan, W., Zhang, Q., He, C., & Saleh, M. (2018). Monte Carlo simulation of the full energy peak efficiency of an HPGe detector. Applied Radiation and Isotopes, 131(November 2017), 67–70. https://doi.org/10.1016/j.apradiso.2017.11.018
• Lépy, M. C., Thiam, C., Anagnostakis, M., Galea, R., Gurau, D., Hurtado, S., … Zhang, M. (2019). A benchmark for Monte Carlo simulation in gamma-ray spectrometry. Applied Radiation and Isotopes, 154, 108850. https://doi.org/10.1016/j.apradiso.2019.108850
• Lin, M., Wang, Y., & Qin, Z. (2023). Determination of detection efficiency on HPGe detector for point-like and volumetric samples based on Geant4 simulations. Applied Radiation and Isotopes, 200, 110989. https://doi.org/ 10.1016/j.apradiso.2023.110989
• Montalván Olivares, D. M., Guevara, M. V. M., & Velasco, F. G. (2017). Determination of the HPGe detector efficiency in measurements of radioactivity in extended environmental samples. Applied Radiation and Isotopes, 130, 34–42. https://doi.org/10.1016/j.apradiso.2017.09.017
• Park, S. Y., Hahn, K. I., Kang, W. G., Kazalov, V., Kim, G. W., Kim, Y. D., ... & Yoon, S. C. (2023). Detection efficiency calibration for an array of fourteen HPGe detectors. Applied Radiation and Isotopes, 193, 110654. https://doi.org/ 10.1016/j.apradiso.2023.110654
• Prozorova, I. V., Ghal-Eh, N., Bedenko, S. V., Popov, Y. A., Prozorov, A. A., & Vega-Carrillo, H. R. (2021). Characterizing the coaxial HPGe detector using Monte Carlo simulations and evolutionary algorithms. Applied Radiation and Isotopes, 174, 109748. https://doi.org/10.1016/j.apradiso.2021.109748
• Sato, T., Iwamoto, Y., Hashimoto, S., Ogawa, T., Furuta, T., Abe, S. ichiro, Niita, K. (2018). Features of Particle and Heavy Ion Transport code System (PHITS) version 3.02. Journal of Nuclear Science and Technology, 55(6), 684–690. https://doi.org/10.1080/00223131.2017.1419890
• Yücel, H., Köse, E., Esen, A. N., & Bor, D. (2011). Correction methodology for the spectral interfering γ-rays overlapping to the analytical peaks used in the analysis of 232Th. Applied Radiation and Isotopes, 69(6), 890–897. https://doi.org/10.1016/j.apradiso.2011.02.027
• Huynh, D. C., Nguyen, H. D. K., Le, T. N. T., Nguyen, T. T. L., Truong, T. S., Nguyen, T. D., & Hoang, D. T. (2023). A comparative study on full-energy peak efficiency calibration methods for HPGe detector: Virtual point detector, curve fitting, and machine learning models. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 168941. https://doi.org/ 10.1016/j.nima.2023.168941