Effective Doses in the Radial Gamma Radiation Field near a Point Source: Gender Difference and Deviation from the Personal Dose Equivalent

점선원 감마선장에서 유효선량의 성별차 및 개연선량당량과의 차이

  • Chang, Jai-Kwon (Department of Nuclear Engineering, Hanyang University) ;
  • Lee, Jai-Ki (Department of Nuclear Engineering, Hanyang University)
  • 장재권 (한양대학교 원자력공학과) ;
  • 이재기 (한양대학교 원자력공학과)
  • Published : 1997.12.30


The individual dose equivalent, $H_p$, effective dose, E, and gender specific effective dose, $E^m$ and E$^f$, were evaluated using the male and female phantoms of MIRD type located in the radial gamma radiation field near a point source. The point sources were placed at the distances of 15, 40 and 100 cm in front of the body at different heights. Two radionuclides, $^{137}Cs$ and $^{131}I$, were selected for the illustrative examples. In terms of the gender specific effective doses, $E^f$ is higher than $E^m$ with a few exceptions, e.g. the case where the point source is at the height of reproductive organs, but the differences from the sex- averaged values are not significant enough to justify use of gender specific dose conversion factors for the radial gamma field. The ratios $H_p$/E were in the range of 1 to 3 depending on the source and dosimeter positions when the dosimeter is worn on the front surface of the torso covering from chest to lower abdomen, but varied from 0.34 to 6.5 in extreme cases. When it is assumed that the typical handling procedure of radioactive source material and the typical dosimeter position(on the chest) be respected, the dosimeters calibrated against the broad parallel field appear to provide estimates with acceptable errors for the effective dose of workers exposed to radial broad gamma field around a point source.