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Kinase, Sakae; Zankl, M.*; Kuwabara, Jun; Sato, Kaoru; Noguchi, Hiroshi; Funabiki, Jun*; Saito, Kimiaki
Radiation Protection Dosimetry, 105(1-4), p.557 - 563, 2003/09
Times Cited Count:27 Percentile:83.75(Environmental Sciences)There exists a need to calculate specific absorbed fractions (SAFs) in voxel phantoms for internal dosimetry. For this purpose, an EGS4 user code for calculating SAFs using voxel phantoms was developed on the basis of an existing EGS4 user code for external dosimetry (UCPIXEL). In the developed code, the transport of photons, electrons and positrons in voxel phantoms can be simulated, particularly the transport simulations of secondary electrons in voxel phantoms can be made. The evaluated SAFs for the GSF Child voxel phantom using the developed code were found to be in good agreement with the GSF evaluated data. In addition, SAFs in adult voxel phantoms developed at JAERI were evaluated using the developed code and were compared with several published data. It was found that SAFs for organ self-absorption depend on the organ masses and would be affected by differences in the structure of the human body.
Takahashi, Fumiaki; Yamaguchi, Yasuhiro; Saito, Kimiaki; Iwasaki, Midori*; Miyazawa, Chuzo*; Hamada, Tatsuji*; Funabiki, Jun*
Journal of Nuclear Science and Technology, 39(Suppl.2), p.1314 - 1317, 2002/08
An analysis of dose to tooth enamel was carried out to develop a method that can predict the organdose and effective dose by the Electron Spin Resonance (ESR) dosimetry using teeth for external photon exposure. Absorbed dose to tooth enamel were obtained with Monte Carlo calculations using EGS4 code with a mathematical human model, which has a newly defined teeth-part. Experiments were also carried out to investigate the dose at the tooth area with a physical head phantom. The calculated doses to tooth enamel were, however, less than the measured doses with the TLDs for the case of photon incidence from the back of a human body. Then, a computational human model, called a "Voxel (Volume-pixel) type" phantom was constructed based upon a computed topography (CT) image of the physical head phantom used in the experiments.The additional Monte Carlo calculations were performed to verify the results in the experiments with the EGS4 in conjunction with user's code UCPIXEL and the Voxel type phantom.