ABSORBED DOSE MEASUREMENTS AND CALCULATIONS IN PHANTOMS FOR 1.5-KEV TO 50-KEV PHOTONS

Monte Carlo code EGS4 expanded for low energy photon transport was val idated by measuring absorbed doses in a phantom for 30 and 10 keV mono energetic photons from synchrotron radiation. Using the EGS4 code, dep th doses at 0.07 mm, 0.02 to 0.1 mm, and 10 mm in the ICRU slab phanto ms were calculated for 1.5 to 50 keV photons using the updated photon cross section data PHOTX. The results show that the doses at 0.02 to 0 .1 mm below 10 keV are practical indices of effective dose as calculat ed by others, based on the 1990 ICRP recommendations (1991).