Applied Chemical Engineering

Energy Resolution Stability of a NaI(Tl) Detector Using 137Cs Source

Ali Hadi Mizal

Department of Physics, College of Education for Pure Sciences, University of Babylon, Iraq

Inaam Hani Kadhim

Department of Physics, College of Education for Pure Sciences, University of Babylon, Iraq

DOI: https://doi.org/10.59429/ace.v9i2.5904

Keywords: NaI(Tl) detector; 137Cs source; energy resolution; gamma rays; R environment; Q–Q plot

---

Abstract

The energy resolution is one of the most important performance parameters of scintillation detectors, and it characterizes their ability to accurately measure gamma-ray energies. In this study, the statistical stability of the energy resolution of a NaI(Tl) scintillation detector was investigated using gamma spectra from a 137Cs source under fixed operational conditions. The energy resolution was determined from the full width at half maximum (FWHM) of the photopeak and analyzed using statistical methods.

Approximately 100 spectra were acquired and analyzed in the R environment using descriptive statistics, normality tests, correlation, and regression analyses. The results show a mean energy resolution of 16.94±0.81, indicating low dispersion and stable detector performance. Although a statistically significant relationship with the measurement sequence was observed, the low coefficient of determination (R2 = 0.24) suggests that the variations are mainly due inherent statistical fluctuations.

Overall, the findings confirm that the NaI(Tl) detector exhibits stable performance under controlled laboratory conditions and demonstrate the effectiveness of statistical time-series analysis for evaluating detector stability.   

---

References

[1]. Debertin, K., & Helmer, R. G. (1988). Gamma- and X-ray spectrometry with semiconductor detectors. North-Holland.

[2]. Akkurt, İ., Waheed, F., Akyildirim, H., & Gunoglu, K. (2020). Monte Carlo simulation of a NaI(Tl) detector efficiency. Radiation Physics and Chemistry, 176, 109081.

[3]. Hofstadter, R. (1949). The detection of gamma-rays with thallium-activated sodium iodide crystals. Physical Review, 75(5), 796.

[4]. Golovko, V. V. (2024). Simplified efficiency calibration methods for scintillation detectors used in nuclear remediation. Journal of Cleaner Production, 478, 143910.

[5]. Arectout, A., Boukhal, H., Chakir, E., Jarmouni, M., Assalmi, M., El Ghalbzouri, T., ... & El Yaakoubi, H. (2024). A comparative analysis of the NaI detector response function using GAMOS and FLUKA Monte Carlo simulations. Nuclear Analysis, 3(4), 100138.

[6]. Zhou, H., Liu, F., Yuan, X., Wu, J., & Li, G. (2024). Effect of photomultiplier tube voltage on the performance of sealed NaI(Tl) scintillator detectors. Science and Technology of Nuclear Installations, 2024(1), 5206668.

[7]. Maeng, S., Lee, S. H., Park, S. J., & Choi, W. C. (2022). Detection efficiency evaluation for low energy of a NaI(Tl) scintillation detector. Radiation Physics and Chemistry, 199, 110325.

[8]. Tarım, U. A., & Gürler, O. (2018). Source-to-detector distance dependence of efficiency and energy resolution of a 3" × 3" NaI(Tl) detector. Avrupa Bilim ve Teknoloji Dergisi, (13), 103–107.

[9]. Pommé, S. (2022). Radionuclide metrology: confidence in radioactivity measurements. Journal of Radioanalytical and Nuclear Chemistry, 331(12), 4771–4798.

[10]. Bu, M., Murray, A. S., Kook, M., Buylaert, J. P., & Thomsen, K. J. (2021). The application of full spectrum analysis to NaI(Tl) gamma-ray spectrometry for the determination of burial dose rates. Geochronometria, 48(1), 161–170.

[11]. Cengiz, G. B., & Çağlar, İ. (2019). A study on calculation of full energy peak efficiency of NaI(Tl) detectors using point source. Caucasian Journal of Science, 6(1), 28–36.