A New Approach for the Calculation of Neutron Dose Equivalent Conversion Coefficients for PMMA Slab Phantom

PMMA 평판형 팬텀에서의 중성자 선량당량 환산계수의 새로운 계산법

  • Kim, Jong-Kyung (Department of Nuclear Engineering, Hanyang University) ;
  • Kim, Jong-Oh (Department of Nuclear Engineering, Hanyang University)
  • 김종경 (한양대학교 원자력공학과) ;
  • 김종오 (한양대학교 원자력공학과)
  • Published : 1996.12.30

Abstract

ANSI decided PMMA slab phantom as a calibration phantom and introduced a conversion coefficient calculation method for it. For photon, the conversion coefficient can be obtained by using backscatter factor and conversion coefficient of the ICRU tissue cube and backscatter factor of the PMMA slab. For neutron, however, the ANSI has not introduced any conversion coefficient calculation method for the PMMA slab. In this work, the ANSI method for the photon conversion coefficient calculation was applied to the neutron conversion coefficient calculation of the PMMA slab. Quality weighted tissue kerma of neutron was applied to calculate the backscatter factors on the ICRU cube and the PMMA slab. The dose conversion coefficient of the ICRU cube was also calculated by using MCNP code. Then, the dose conversion coefficient of the PMMA slab was calculated from two backscatter factors and the dose conversion coefficient of the ICRU cube. The discrepancies of the dose conversion coefficients of the PMMA slab and the ICRU cube were less than 10% except 1eV(20%), 1keV(17%), and 4 MeV(16%).