Journal of Radiation Protection and Research

The Korean Association for Radiation Protection (대한방사선방어학회)
권호 표지
DOI QR코드

DOI QR Code

In Situ Gamma-ray Spectrometry Using an LaBr3(Ce) Scintillation Detector

  • Received : 2018.06.15
  • Accepted : 2018.08.27
  • Published : 2018.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

Background: A variety of inorganic scintillators have been developed and improved for use in radiation detection and measurement, and in situ gamma-ray spectrometry in the environment remains an important area in nuclear safety. In order to verify the feasibility of promising scintillators in an actual environment, a performance test is necessary to identify gamma-ray peaks and calculate the radioactivity from their net count rates in peaks. Materials and Methods: Among commercially available scintillators, $LaBr_3(Ce)$ scintillators have so far shown the highest energy resolution when detecting and identifying gamma-rays. However, the intrinsic background of this scintillator type affects efficient application to the environment with a relatively low count rate. An algorithm to subtract the intrinsic background was consequently developed, and the in situ calibration factor at 1 m above ground level was calculated from Monte Carlo simulation in order to determine the radioactivity from the measured net count rate. Results and Discussion: The radioactivity of six natural radionuclides in the environment was evaluated from in situ gamma-ray spectrometry using an $LaBr_3(Ce)$ detector. The results were then compared with those of a portable high purity Ge (HPGe) detector with in situ object counting system (ISOCS) software at the same sites. In addition, the radioactive cesium in the ground of Jeju Island, South Korea, was determined with the same assumption of the source distribution between measurements using two detectors. Conclusion: Good agreement between both detectors was achieved in the in situ gamma-ray spectrometry of natural as well as artificial radionuclides in the ground. This means that an $LaBr_3(Ce)$ detector can produce reliable and stable results of radioactivity in the ground from the measured energy spectrum of incident gamma-rays at 1 m above the ground.

Keywords

References

  1. Mikami S, Sato S, Hoshide Y, Sakamoto R, Okuda N, Saito K. In situ gamma spectrometry intercomparison in Fukushima, Japan. Japanese Journal of Health Physics. 2015;50(3):182-188. https://doi.org/10.5453/jhps.50.182
  2. Ji YY, Kim CJ, Chung KH, Choi HY, Lee W, Park ST, Kang MJ. Simultaneous determination of the depth an embedded source and its radioactivity in the medium. Health. Phys. 2016;111(5): S183-S192. https://doi.org/10.1097/HP.0000000000000560
  3. Ji YY, Kim CJ, Chung KH, Choi HY, Lee W, Kang MJ, Park ST. In situ gamma-ray spectrometry in the environment using dose rate spectroscopy. Radiat. Phys. Chem. 2016;119:90-102. https://doi.org/10.1016/j.radphyschem.2015.10.001
  4. Ji YY, Kim CJ, Lim KS, Lee W, Chang HS, Chung KH. A new approach for the determination of dose rate and radioactivity for detected gamma nuclides using an environmental radiation monitor based on an NaI(Tl) detector. Health. Phys. 2017;113(4): 304-314. https://doi.org/10.1097/HP.0000000000000706
  5. Shuichi T, Kimiaki S. Spectrum-dose conversion operator of NaI (Tl) and CsI(Tl) scintillation detectors for air dose measurement in contaminated environment. J. Environ. Radioact. 2017;166: 419-426. https://doi.org/10.1016/j.jenvrad.2016.02.008
  6. Cherepy NJ, et al. Scintillators with potential to supersede lanthanum bromide. IEEE Trans. Nucl. Sci. 2009;56(3):873-880. https://doi.org/10.1109/TNS.2009.2020165
  7. Quarati FGA, Dorenbos P, Biezen JVD, Owens A, Selle M, Parthier L, Schotanus P. Scintillation and detection characteristics of high-sensitivity CeBr3 gamma-ray spectrometers. Nucl. Instrum. Methods Phys. Res., Sect. A. 2013;729:596-604. https://doi.org/10.1016/j.nima.2013.08.005
  8. Takabe M, Kishimoto A, Kataoka J, Sakuragi S, Yamasaki Y. Performance evaluation of newly developed SrI2(Eu) scintillator. Nucl. Instrum. Methods Phys. Res., Sect. A. 2016;831:260-264. https://doi.org/10.1016/j.nima.2016.04.043
  9. Gonzalez R, Perez JM, Vela O, Burgos ED. Performance comparison of a large volume CZT semiconductor detector and a $LaBr_3$ (Ce) scintillator detector. IEEE Trans. Nucl. Sci. 2006;53(4):2409-2415. https://doi.org/10.1109/TNS.2006.877853
  10. Alzimami K, Abuelhia E, Podolyak Z, Ioannou A, Spyrou N. Characterization of $LaBr_3$:Ce and $LaCl_3$:Ce scintillators for gamma-ray spectroscopy. J. Radioanal. Nucl. Chem. 2008;278(3):755-759. https://doi.org/10.1007/s10967-008-1606-6
  11. International Commission on Radiation Units and Measurements. Gamma-Ray spectrometry in the environment. ICRU Report 53. 1994;15-27.
  12. Korea Atomic Energy Research Institute. Determination of the detector response function for aerial radiological survey. KAERI/ CR-530/2013. 2013;11-30.
  13. Korea Atomic Energy Research Institute. Development of correction factors and their evaluations in the aerial radiological survey. KAERI/CR-573/2014. 2014;9-30.
  14. Health and Safety Laboratory. In situ Ge(Li) and NaI(Tl) gammaray spectrometry. HASL-258. 1972;6-18.
  15. Helfer IK, Miller KM. Calibration factors for Ge detectors used for field spectrometry. Health. Phys. 1988;55(1):15-29. https://doi.org/10.1097/00004032-198807000-00002
  16. International Atomic Energy Agency. ALMERA proficiency test: Determination of natural and artificial radionuclides in soil and water. IAEA analytical quality in nuclear applications series, No. 32. IAEA/AQ/32. 2011;13-14.
  17. Ji YY, Kim CJ, Lim JM, Kim H, Chung KH. Validation of the quantification of natural radionuclides in raw materials and by-products using gamma-ray spectrometry. Accredit. Qual. Assur. 2016; 21(6):403-408. https://doi.org/10.1007/s00769-016-1238-4

Cited by

  1. IN-SITU GAMMA-RAY SPECTROMETRY FOR RADIOACTIVITY ANALYSIS OF SOIL USING NaI(Tl) AND LaBr3(Ce) DETECTORS vol.187, pp.3, 2018, https://doi.org/10.1093/rpd/ncz165
  2. Development of background simulation model for commercial radiation portal monitor using Monte Carlo code vol.79, pp.6, 2018, https://doi.org/10.1007/s40042-021-00272-2
  3. Gamma-ray Spectroscopy Using Inorganic Scintillator Coated with Reduced Graphene Oxide in Fiber-Optic Radiation Sensor vol.8, pp.12, 2021, https://doi.org/10.3390/photonics8120543