Journal of the Korean Society of Radiology (한국방사선학회논문지)

The Korean Society of Radiology (한국방사선학회)
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Determination of the Equivalent Energy of a 6 MV X-ray Beam

6 MV X-선 빔의 등가에너지 결정

  • Kim, Jong-Eon (Department of Radiological Science, Kaya University) ;
  • Park, Byung-Do (Department of Radiation Oncology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine)
  • 김종언 (가야대학교 방사선학과) ;
  • 박병도 (성균관대학교 의과대학 삼성창원병원 방사선종양학과)
  • Received : 2016.11.09
  • Accepted : 2016.12.31
  • Published : 2016.12.31
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Abstract

The purpose of this study is to determine the equivalent energy of a 6MV X-ray beam in the experiment. The half-value layer (HVL) of lead for the 6 MV X-ray beam was measured using an ionization chamber. The linear attenuation coefficients were calculated with HVL. And, the mass attenuation coefficient was obtained by dividing the linear attenuation coefficient by the density of lead. The equivalent energy of mass attenuation coefficient was determined using the photon energy versus mass attenuation coefficient data of lead given by National Institute of Standards and Technology (NIST). In conclusion, the equivalent energy of the 6 MV X-ray beam was determined to be 1.61 MeV. This equivalent energy was determined to be about 30% lower than reported by Reft. The reason is presumed to be due to the presence of an air cavity between the lead attenuators.

본 연구의 목적은 실험으로 6 MV X-선 빔의 등가에너지를 결정하는 데 있다. 6 MV X-선 빔에 대한 납의 반가층은 전리함을 사용하여 측정하였다. 선감쇠계수는 측정된 반가층을 사용하여 계산하였다. 그리고 질량감쇠계수는 납의 밀도로 선감쇠계수를 나누어 얻었다. 얻어진 질량감쇠계수의 등가에너지는 미국표준기술연구소에서 주어진 납의 광자에너지 대 질량감쇠계수 자료를 사용하여 결정하였다. 그 결과로서, 6 MV X-선 빔에 대한 등가에너지는 1.61 MeV로 결정되었다. 이 등가에너지는 Reft가 보고한 것 보다 약 30% 낮게 결정되었다. 그 원인은 납 감쇠기 사이의 공기공동의 존재에 기인한 것으로 추정된다.

Keywords

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