Semi-empirical calibration of full-energy peak efficiency for Marinelli beaker geometry based on density-dependent attenuation modeling
Radiation Measurements, cilt.197, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 197
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.radmeas.2026.107760
- Dergi Adı: Radiation Measurements
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Detector efficiency, Gamma-ray detection, Gamma-ray detector, Marinelli geometry, Radiation measurement
- Marmara Üniversitesi Adresli: Hayır
Özet
Gamma-ray spectrometry requires accurate calibration of full-energy peak (FEP) efficiency, particularly when complex sample geometries such as Marinelli beakers are employed. This work develops and validates an analytic calibration framework tailored to a 3″ × 3″ NaI(Tl) detector operating with mixed γ-emitting standards across 60–1837 keV. Measurements are performed at three matrix densities (0.7, 1.0, and 1.3 g cm−3), enabling systematic evaluation of density-dependent self-attenuation. Experimental efficiencies are first represented by log-polynomial fits and then generalized into a factorized model that separates intrinsic detector response from matrix attenuation. The attenuation component is physically motivated by the energy dependence of mass attenuation coefficients reported in the NIST XCOM database, while the attenuation behavior is calibrated empirically. The analytic formulation reproduces experimental data with mean absolute percentage errors near 1% and RMSE values between 0.10 and 0.17 efficiency units. Residual analysis shows that discrepancies are most evident at low energies, consistent with strong self-attenuation, while agreement improves at higher energies. The effective path length decreases with energy, reflecting reduced density sensitivity in the MeV range. Overall, the study demonstrates that a physically motivated factorization combined with empirical calibration provides a compact, accurate, and interpretable framework for Marinelli-specific efficiency modeling, bridging empirical fitting and Monte Carlo simulation for routine γ-ray spectrometry applications.