Skip to main content
Log in

MCNP5 evaluation of a response matrix of a Bonner Sphere Spectrometer with a high efficiency 6LiI (Eu) detector from 0.01 eV to 20 MeV neutrons

  • Published:
Journal of Radioanalytical and Nuclear Chemistry Aims and scope Submit manuscript

Abstract

A new approach has been suggested to establish reliable response matrix of a CRNA Bonner Sphere Spectrometer equipped with a high efficiency 10 mm diameter × 2 mm thick 6LiI (Eu) scintillation detector from thermal neutron energy up to 20 MeV. It combines the experimental response functions obtained using a continuous neutron spectrum emitted from an 241Am-Be neutron source of known emission, with those obtained by Monte-Carlo (MC) calculations. Sensitivity analysis has been performed to check the influence of pertinent parameters on the MC computed detector response. The parameters of interest are the density of polyethylene moderators, the cross section library used in MCNP5 and two computing models depending on the interactions of the neutrons in the detector. The calculated responses of the spectrometer to the 241Am-Be neutron source showed discrepancies depending on the sphere diameter when compared to our measured responses. However, this difference was smaller compared with the experiments available in the literature. The enhancement achieved in the present study is partly due to improved modeling in the MC calculations. To correct for the differences observed, a fitting factor has been deduced for each sphere diameter and used to adjust the MC responses to the experimental ones. The obtained results were subsequently compared to the experimental data of GSF-G spheres system obtained for a typical 4 mm diameter × 4 mm thick 6LiI scintillator for four ISO-8529 selected neutron energies (144.0 keV, 565 keV, 2.5 and 14.8 MeV). The present responses were similar in shape but higher, in absolute values, by about two and half times for all spheres owing essentially to the increase in active part of the detector. Finally, the CRNA-BSS response matrix containing 48 energy points from 0.01 eV to 20 MeV for 22 sphere diameters with a mean polyethylene density of 0.944 g/cm3 was constructed by applying a spline interpolation method. The released response matrix was then compared to data available in the literature evaluated by Monte-Carlo calculations for a 4 mm × 4 mm 6LiI crystal scintillator. The obtained response matrix is intended for radiation protection applications at CRNA.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

Similar content being viewed by others

References

  1. Brooks FD, Klein H (2000) Neutron spectrometry—historical review and Present Status. In: Proceedings of the international workshop on neutron field spectrometry in science, technology and radiation protection, Pisa, Italy, 4–8 June 2000. Nucl Instrum Methods Phys Res A 476:1–11 (2002)

  2. Thomas DJ, Alevra AV (2000) Bonner Sphere Spectrometers—a critical review. In: Proceedings of the international workshop on neutron field spectrometry in science, technology and radiation protection, Pisa, Italy, 4–8 June 2000. Nucl Instrum Methods Phys Res A 476:12–20 (2002)

  3. Thomas DJ (2004) Neutron spectrometry for radiation protection. Radiat Prot Dosimetry 110(1–4):141–149

    Article  CAS  Google Scholar 

  4. Alevra AV, Thomas DJ (2003) Neutron spectrometry in mixed fields: multisphere spectrometers. Radiat Prot Dosimetry 107(1–3):37–72

    CAS  Google Scholar 

  5. Mares V, Schraube G, Schraube H (1991) Calculated neutron response of a Bonner Sphere Spectrometer with 3He counter. Nucl Instrum Methods Phys Res A 307:398–412

    Article  Google Scholar 

  6. Alevra AV, Cosack M, Hunt JB, Thomas DJ, Schraube H (1992) Experimental determination of the response of four Bonner sphere sets to monoenergetic neutrons (II). Radiat Prot Dosimetry 40(2):91–102

    CAS  Google Scholar 

  7. Siebert BRL, Dietz E, Jetzke S (1992) Comparison of measured and calculated Bonner sphere responses for 24 and 144 keV incident neutron energies. Radiat Prot Dosimetry 44(1–4):89–92

    CAS  Google Scholar 

  8. Thomas DJ, Alevra AV, Hunt JB, Schraube H (1994) Experimental determination of the response of four Bonner sphere sets to thermal neutrons. Radiat Prot Dosimetry 54(1):25–31

    CAS  Google Scholar 

  9. Kralik M, Aroua A, Grecescu M, Mares V, Novotny T, Schraube H, Weigel B (1997) Specification of Bonner sphere systems for neutron spectrometry. Radiat Prot Dosimetry 70(1–4):279–284

    CAS  Google Scholar 

  10. Mares V, Schraube H (1994) Evaluation of the response matrix of a Bonner Sphere Spectrometer with LiI detector from thermal energy to 100 MeV. Nucl Instrum Methods Phys Res A 337:461–473

    Article  CAS  Google Scholar 

  11. Mazrou H, Sidahmed T, Idiri Z, Lounis-Mokrani Z, Bedek S, Allab M (2008) Characterization of the CRNA Bonner Sphere Spectrometer based on 6LiI scintillator exposed to an 241Am-Be neutron source. Radiat Meas 43:1095–1099

    Article  CAS  Google Scholar 

  12. Bedogni R, Esposito A, Gentile A, Angelone M, Gualdrini G (2008) Determination and validation of a response matrix for a passive Bonner Sphere Spectrometer based on gold foils. Radiat Meas 43:1104–1107

    Article  CAS  Google Scholar 

  13. Garny S, Mares V, Ruhm W (2009) Response functions of a Bonner Sphere Spectrometer calculated with GEANT4. Nucl Instrum Methods Phys Res A 604:612–617

    Article  CAS  Google Scholar 

  14. International Organization for Standardization (2001) Reference neutron radiations, part 1: characteristics and methods of production. ISO 8529-1

  15. Berthold (1984) Neutron Rem dose ratemeter LB 140. Berthold technical report LB 49-2-0979 E

  16. MCNP5 2003 (2003) A general Monte-Carlo N-particle transport code, Version 5. X-5 Monte Carlo Team. Report LA-UR-03-1987, Los Alamos National Laboratory, April 24

  17. Wiegel B, Alevra AV, Siebert BRL (1994) Calculations of the response functions of Bonner spheres with a spherical 3He proportional counter using a realistic detector model. PTB-N-21. ISBN 3-89429-563-5

  18. MacFarlane RE (1994) New thermal neutron scattering files for ENDF/B-VI release 2. Los Alamos National Laboratory report LA-12639-MS (also released as ENDF-356 by the National Nuclear Data Center at the Brookhaven National Laboratory), August 1994

  19. Tanner RJ (2004) P4: response of a TLD-albedo personnal dosemeter on an ISO slab phantom. In: Gualdrini G, Ferrari P (eds) Intercomparison of the usage of computational codes in radiation dosimetry, international workshop proceedings, Bologna, Italy. ENEA, pp 169–187

  20. International Organization for Standardization (2000) Reference neutron radiations, part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field, ISO-8529/2

  21. Aroua A, Grecescu M, Lanfranchi M, Lerch P, Pretre S, Valley JF (1992) Evaluation and test of the response matrix of a multisphere neutron spectrometer in a wide energy range. Nucl Instrum Methods Phys Res A 321:305–311

    Article  Google Scholar 

Download references

Acknowledgments

One of the authors (H. Mazrou) would like to express his heartfelt thanks to Dr. N. Zenine from Theoretical Physics Division (DP/CRNA) and Dr. M. Kralik from Czech Metrology Institute (CMI), for their precious suggestions to improve the response matrix of the CRNA-BSS counting system.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hakim Mazrou.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mazrou, H., Idiri, Z., Sidahmed, T. et al. MCNP5 evaluation of a response matrix of a Bonner Sphere Spectrometer with a high efficiency 6LiI (Eu) detector from 0.01 eV to 20 MeV neutrons. J Radioanal Nucl Chem 284, 253–263 (2010). https://doi.org/10.1007/s10967-010-0493-9

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10967-010-0493-9

Keywords

Navigation