Source-to-detector Distance Dependence of Efficiency and Energy Resolution of a 3"x3" NaI(Tl) Detector

Öz

NaI(Tl) scintillation detectors are widely used in measurements of environmental radioactivity, low level radioactive waste, prompt gamma ray neutron activation analysis, some nuclear physics experiments, geology, etc. This paper reports the results of the energy calibration, resolution and full energy peak efficiency and total efficiency calculations for a 3"x3" NaI(Tl) detector (Canberra Inc.) that are essential to specify the quality of the results of gamma spectrometry measurements. To investigate the effects of the gamma ray energy and the distance from source to detector center on detector efficiency, measurements were performed at different six axial distances for four point sources (Am-241, Cs-137, Co-60 and Na-22). Thus, fundamental data for further works with this detector system were obtained.

Anahtar Kelimeler

• Gamma ray,NaI(Tl),Full energy peak efficiency,Total efficiency

Source-to-detector Distance Dependence of Efficiency and Energy Resolution of a 3"x3" NaI(Tl) Detector

Abstract

NaI(Tl) scintillation detectors are widely used in measurements of environmental radioactivity, low level radioactive waste, prompt gamma ray neutron activation analysis, some nuclear physics experiments, geology, etc. This paper reports the results of the energy calibration, resolution and full energy peak efficiency and total efficiency calculations for a 3"x3" NaI(Tl) detector (Canberra Inc.) that are essential to specify the quality of the results of gamma spectrometry measurements. To investigate the effects of the gamma ray energy and the distance from source to detector center on detector efficiency, measurements were performed at different six axial distances for four point sources (Am-241, Cs-137, Co-60 and Na-22). Thus, fundamental data for further works with this detector system were obtained.

Keywords

• Gamma ray,NaI(Tl),Full energy peak efficiency,Total efficiency,Resolution

References

1. Abbas, M. I. (2010). Analytical approach to calculate the efficiency of 4π NaI(Tl) gamma-ray detectors for extended sources. Nuclear Instruments and Methods in Physics Research A, 615, 48–52.
2. Abd-Elzaher, M., Badawi, M. S., El-Khatib, A., Thabet, A. A. (2012). Determination of full energy peak efficiency of NaI(Tl) detector depending on efficiency transfer principle for conversion form experimental values. World Journal of Nuclear Science and Technology, 2, 65–72.
3. Akkurt, I., Gunoglu, K., and Arda, S. S. (2014). Detection efficiency of NaI(Tl) detector in 511–1332 keV energy range. Science and Technology of Nuclear Installations, 2014, 1–5.
4. Alexiev, D., Mo, L., Prokopovich, D. A., Smith, M. L., and Matuchova, M. (2008). Comparison of LaBr3:Ce and LaCl3 :Ce with NaI(Tl) and Cadmium Zinc Telluride (CZT) Detectors. IIE Transactions (Institute of Industrial Engineers) IEEE Transactions on Nuclear Science, 55(3), 1174–1177.
5. Anil Kumar, G., Mazumdar, I., and Gothe, D. A. (2009). Efficiency calibration and coincidence summing correction for large arrays of NaI(Tl) detectors in soccer-ball and castle geometries. Nuclear Instruments and Methods in Physics Research A, 611, 76-83.
6. Ayaz-Maierhafer, B. and DeVol, T. A. (2007). Determination of absolute detection efficiencies for detectors of interest in homeland security. Nuclear Instruments and Methods in Physics Research A, 579, 410-413.
7. Badawi, M. S., Abd-Elzaher, M., Thabet, A. A., El-khatib, A. M. (2013a). An empirical formula to calculate the full energy peak efficiency of scintillation detectors. Applied Radiation and Isotopes, 74, 46–49.
8. Badawi, M. S., Krar, M. E., El-Khatib, A. M., Jovanovic, S. I., Dlabac, A. D., and Mihaljevic, N. N. (2013b). A new mathematical model for determining full-energy peak efficiency of an array of two gamma detectors counting rectangular parallelepiped sources. Nuclear Technology & Radiation Protection, vol. 28(4), 370-380.

9. Casanovas, R., Morant, J. J., and Salvado´, M. (2012). Energy and resolution calibration of NaI(Tl) and LaBr3(Ce) scintillators and validation of an EGS5 Monte Carlo user code for efficiency calculations. Nuclear Instruments and Methods in Physics Research A, 675, 78–83.
10. Demir, D., Un, A., and Sahin, Y. (2008). Efficiency determination for NaI (Tl) detectors in the 23 keV to 1333 keV energy range. Instrumentation Science and Technology, 36, 291–301.
11. Guss, P., Reed, M., Yuan, D., Cutler, M., Contreras, C., and Beller, D. (2010) Comparison of CeBr3 with LaBr3:Ce, LaCl3:Ce, and NaI:Tl Detectors. in Proceedings of SPIE, 7805 78050L-1-78050L. SPIE, pp. 1–16.
12. Hamzawy, A. (2014). New analytical approach to calculate the detector efficiencies of NaI(Tl) using coaxial and off-axis rectangular and parallelepiped sources. Nuclear Instruments and Methods in Physics Research A, 768, 164–169.
13. Hassan Ali, A., Khalaf Mheemeed, A., and Ihsan Hassan H. (2014). Efficiency calibration study of NaI(TL) detector for radioactivity measurements in soils from Ain Zalah Oil Field. World Applied Sciences Journal, 32(3), 359–367.
14. International Atomic Energy Agency Nuclear Data Services https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html (available April 4, 2018)
15. Jehouani, A., Ichaoui, R., and Boulkheir, M. (2000). Study of the NaI(Tl) efficiency by Monte Carlo method. Applied Radiation and Isotopes, 53, 887-891.
16. Karadeniz, Ö. and Vurmaz, S. (2017). Experimental investigation on the photopeak efficiency of a coaxial High Purity Germanium Detector for different geometries. Journal of Basic and Clinical Health Sciences, 1, 18–22.
17. Perez-Andujar, A. and Pibida, L. (2004). Performance of CdTe, HPGe and NaI(Tl) detectors for radioactivity measurements. Applied Radiation and Isotopes, 60, 41–47.
18. Rehman, S. U., Mirza, S. M., and Mirza, N. M. (2009). A fast, primary-interaction Monte Carlo methodology for determination of total efficiency of cylindrical scintillation gamma-ray detectors. Nuclear Technology & Radiation Protection, 3, 195-203.
19. Salgado, C. M., Brandão, L. E. B., Schirru, R., Pereira, C. M. N. A., and Conti, C. C. (2012). Validation of a NaI(Tl) detector’s model developed with MCNP-X code. Progress in Nuclear Energy, 59, 19-25.
20. Selim, Y. S. and Abbas, M. I. (1996). Direct calculation of the total efficiency of cylindrical scintillation detectors for extended circular sources. Radiation Physics and Chemistry, vol. 48(1), pp. 23–27.
21. Selim, Y. S., Abbas, M. I., and Fawzy, M. A. (1998). Analytical calculation of the efficiencies of gamma scintillators. Part I: Total efficiency for coaxial disk sources. Radiation Physics and Chemistry, 53, 589–592.