Determination of Dose Correction Factor for Energy and Directional Dependence of the MOSFET Dosimeter in an Anthropomorphic Phantom

인형 모의피폭체내 MOSFET 선량계의 에너지 및 방향 의존도를 고려하기 위한 선량보정인자 결정

  • 조성구 (한양대학교 원자력공학과) ;
  • 최상현 (한양대학교 원자력공학과) ;
  • 나성호 (한국원자력안전기술원) ;
  • 김찬형 (한양대학교 원자력공학과)
  • Published : 2006.06.30

Abstract

In recent years, the MOSFET dosimeter has been widely used in various medical applications such as dose verification in radiation therapeutic and diagnostic applications. The MOSFET dosimeter is, however, mainly made of silicon and shows some energy dependence for low energy Photons. Therefore, the MOSFET dosimeter tends to overestimate the dose for low energy scattered photons in a phantom. This study determines the correction factors to compensate these dependences of the MOSFET dosimeter in ATOM phantom. For this, we first constructed a computational model of the ATOM phantom based on the 3D CT image data of the phantom. The voxel phantom was then implemented in a Monte Carlo simulation code and used to calculate the energy spectrum of the photon field at each of the MOSFET dosimeter locations in the phantom. Finally, the correction factors were calculated based on the energy spectrum of the photon field at the dosimeter locations and the pre-determined energy and directional dependence of the MOSFET dosimeter. Our result for $^{60}Co$ and $^{137}Cs$ photon fields shows that the correction factors are distributed within the range of 0.89 and 0.97 considering all the MOSFET dosimeter locations in the phantom.

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