Response of LiF-TLD micro-rods around 125I radioactive seed.

摘要: The EGSnrc Monte Carlo system has been used to calculate the energy response of LiF-TLDs different sizes around 125I permanent brachytherapy sources. source model includes effects an encapsulation, self-absorption within and in welded ends encapsulation. LiF-TLD material cylindrical geometry (micro-rod) with diameters ranging from 1 mm 5 a length 6 mm. factor (relative 60Co γ-rays) for calibrated γ-rays then irradiated by varies between 1.32 ± 0.2% (1 SD) 1.406 diameter micro-rods, respectively. depends on radius polar angle (r, θ) measurement point. For at cm transverse axis (r = 1.0 cm, θ 90°) water, decreases maximum 3.5% × calculation region. LiF-TLD, 5% same An examination photon spectra showed that spectrum does not change significantly water 3D region (6 cm). mass absorption coefficient ratio vary more than 0.5% this grid. results, however, show there is distance LiF-TLDs. This difference gives rise LiF (calculated taking into account fluence LiF) calculated assuming identical.