• Title/Summary/Keyword: 방사선가중인자

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Definition and Difference between Dose Equivalent and Equivalent Dose in Radiation Dose Measurement and Evaluation (방사선량의 측정, 평가에서 선량당량(dose equivalent)과 등가선량(equivalent dose)의 정의 및 차이)

  • Chang, Si-Young
    • Journal of Radiation Protection and Research
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    • v.18 no.1
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    • pp.1-7
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    • 1993
  • In its recent recommendation No. 60(1990), ICRP has newly introduced several terminology which had not existed in its prior recommendation No. 26(1977). Of these, a newly defined quantity 'Equivalent Dose' replacing the 'Dose Equivalent' of the ICRU concept has been recommended to be adopted in the radiation protection programme. However, since the committee still uses the 'Dose Equivalent' and 'Equivalent Dose' in its several publications, it is likely to provoke unnecessary confusions and misuses in applying these two quantities. In this paper were described the definition and difference between these two quantities to help in understanding of these two quantitites among the person involved in the radiation protection activities.

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Characterization of Physical Processes and Secondary Particle Generation in Radiation Dose Enhancement for Megavoltage X-rays (MV X선의 방사선 선량 증강 현상에서 물리적 특성과 이차입자의 발생)

  • Hwang, Chulhwan;Kim, JungHoon
    • Journal of the Korean Society of Radiology
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    • v.13 no.5
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    • pp.791-799
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    • 2019
  • We evaluated the physical properties that occur to dose enhancement and changes from secondary particle production resulting from the interaction between enhancement material. Geant4 was used to perform a Monte Carlo simulation, and the medical internal radiation dose (MIRD) head phantom were employed. X-rays of 4, 6, 10, 15, 18, and 25 MV were used. Aurum (Au) and gadolinium (Gd) were applied within the tumor volume at 10, 20, and 30 mg/g, and an experiment using soft tissue exclusively was concomitantly performed for comparison. Also, particle fluence and initial kinetic energy of secondary particle of interaction were measured to calculate equivalent doses using the radiation weight factor. The properties of physical interaction by the radiation enhancement material showed the great increased in photoelectric effect as compared to the compton scattering and pair production, occurred with the highest, in aurum and gadolinium it is shown in common. The photonuclear effect frequency increased as the energy increased, thereby increasing secondary particle production, including alpha particles, protons, and neutrons. During dose enhancement using aurum, a maximum 424.25-fold increase in the equivalent dose due to neutrons was observed. This study was Monte Carlo simulation corresponds to the physical process of energy transmission in dose enhancement. Its results may be used as a basis for future in vivo and in vitro experiments aiming to improve effects of dose enhancement.

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;Kim, Jong-Oh
    • Journal of Radiation Protection and Research
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    • v.21 no.4
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    • pp.297-311
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    • 1996
  • 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%).

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