Appl Radiat Isot. 2025 Sep 4;226:112161. doi: 10.1016/j.apradiso.2025.112161. Online ahead of print.
ABSTRACT
Accurate determination of the parameters of each high purity germanium, HPGe detectors ensure the precision of quantitative results obtained from spectrum analysis. This study presents a comprehensive performance evaluation and long-term quality control assessment of a high-purity germanium (HPGe) gamma spectrometry system that has been operational for over 15 years. Key spectrometric measures were recorded, including energy resolution, peak shape ratios, asymmetry, peak-to-Compton ratio, relative efficiency, electronic noise, minimum detectable activity (MDA), and repeatability and reproducibility of the system. With the assistance of a calibrated source Co-60, the detector exhibited a commendable energy resolution of 2.01 keV (FWHM), along with good peak shape ratios (FWTM/FWHM = 1.73, FWFM/FWHM = 2.48) and a peak-to-Compton ratio of 52.2, indicating high resolution and zero spectral distortion. Relative detector efficiency was 33.88 % at 1332.5 keV, and electronic noise was negligible at 0.178 %. MDA for certain radionuclides was found to be in the range 0.048-0.605 Bq/kg, which showed good sensitivity even for low-activity peaks. Repeatability tests gave a coefficient of variation (%CV) less than 1 % for all peaks measured, while reproducibility was confirmed with t-test and F-test statistical tests. A Shewhart X‾-control chart revealed that at all times in all cases, measurements were within control limits, though a slight downward trend in the last few years suggests potential need for recalibration or maintenance. The findings corroborate the sustained conformity of the system to ISO/IEC 17025 quality standards and its sufficiency for precise and trustworthy gamma-ray analysis in radionuclide quantification and environmental monitoring.
PMID:40929755 | DOI:10.1016/j.apradiso.2025.112161
