DOI QR코드

DOI QR Code

EXPERIMENTAL VALIDATION OF THE BACKSCATTERING GAMMA-RAY SPECTRA WITH THE MONTE CARLO CODE

  • 투고 : 2010.12.21
  • 발행 : 2011.02.25

초록

In this study, simulations were done of a 661.6 keV line from a point source of $^{137}Cs$ housed in a lead shield. When increasing the scattering angle from 60 to 120 degrees with a 6061 aluminum alloy target placed at angles of 30 and 45 degrees to the incident beam, the spectra showed that the single scattering component increases and that the multiple scattering component decreases. The investigation of the single and multiple scattering components was carried out using a MCNP5 simulation code. The component of the single Compton scattering photons is proportional to the target electron density at the point where the scattering occurs. The single scattering peak increases according to the thickness of the target and saturates at a certain thickness. The signal-to-noise ratio was found to decrease according to the target thickness. The simulation was experimentally validated by measurements. These results will be used to determine the best conditions under which this method can be applied to testing electron densities or to assess the thickness of samples to locate defects in them.

키워드

참고문헌

  1. L.M.N. Tavora, W.B. Gilboy, Study of Compton scattering signals in single-sided imaging applications using Monte Carlo methods, Nuclear Instruments and Methods in Physics Research B213 (2004) 155–161.
  2. Glenn F. Knoll, Radiation Detection and Measurement, John Wiley & Sons, Inc (2000).
  3. Gurvinderjit Singh, Manpreet Singh, B.S. Sandhu, Bhajan Singh, Experimental investigation of multiple scattering of 662 keV gamma rays in zinc at $90^{\circ}$, Radiation Physics and Chemistry 76 (2007) 750–758.
  4. Manpreet Singh, Gurvinderjit Singh, B.S. Sandhu, Bhajan Singh, Effect of detector collimator and sample thickness on 0.662 MeV multiply Compton-scattered gamma rays, Applied Radiation and Isotopes 64 (2006) 373–378. https://doi.org/10.1016/j.apradiso.2005.08.015
  5. X-5 Monte Carlo Team, MCNP - A General Monte Carlo N-Particle Transport Code, Version 5, Volume II: User's Guide. Los Alamos National Laboratory Report LA-CP-03-0245, 2003.
  6. Hassan A. Jama, Esam M.A. Hussein, Design aspects of a gamma-ray energy-spectral Compton-scatter nondestructive testing method, Applied Radiation and Isotopes 50 (1999) 3731–342. https://doi.org/10.1016/S0969-8043(97)10125-7
  7. Esam M.A. Hussein, Handbook on Radiation Probing, Gauging, Imaging and Analysis, Volume II, Kluwer Academic Publishers (2004).
  8. http://www.mcnpvised.com/
  9. Y. Wua, FDS Team, CAD-based interface programs for fusion neutron transport simulation, Fusion Engineering and Design 84 (2009) 1987-1992. https://doi.org/10.1016/j.fusengdes.2008.12.041
  10. http://worm.csirc.net/index.htm
  11. James Laird, Darby S. Kimball, MCNP Variance reduction techniques: what to use when and how, American nuclear society winter meeting (2009).
  12. Richard H. Olsher, A practical look at Monte Carlo variance reduction methods in radiations shielding, Nuclear Engineering and Technology, vol.38, No.3 April 2006.
  13. Jonas Boson, GoranAgren, Lennart Johansson, A detailed investigation of HPGe detector response for improved Monte Carlo efficiency calculations, Nucl. Instr. Meth., A 587 (2008) 304–314. https://doi.org/10.1016/j.nima.2008.01.062
  14. Avneet Sood and Morgan C. White, Doppler Energy Broadening for Incoherent Scattering in MCNP5, Part II, Los Alamos National Laboratory Report LA-UR 04-0488.
  15. J. Rodenas, A. Pascual, I. Zarza, V. Serradell, J. Ortiz, L. Ballesteros, Analysis of the influence of germanium dead layer on detector calibration simulation for environmental radioactive samples using the Monte Carlo method, Nucl. Instr. and Meth, A 496 (2003) 390–399. https://doi.org/10.1016/S0168-9002(02)01748-5
  16. Huy N.Q., Binh D.Q., An V.X. (2007), "Study on the increase of inactive germanium layer in a high purity germanium detector after a long time operation applying MCNP code", Nucl. Instrum. Methods, A 573 384-388. https://doi.org/10.1016/j.nima.2006.12.048
  17. Fernandez, J.E., Compton and Rayleigh double scattering of unpolarized radiation, Phys. Rev. (1991) A44, 4232-4248.