AIR KERMA TO DOSE-EQUIVALENT CONVERSION COEFFICIENTS FOR CYLINDRICAL PHANTOMS IRRADIATED BY EXTENDED PLANE-PARALLEL PHOTON BEAMS OF OBLIQUE-INCIDENCE RELATIVE TO THE CYLINDER MAIN AXIS

For the purposes of type testing extremity dosemeters, the conversion coefficients between the receptor-free air collision kerma and the col lision kerma for 4-element ICRU tissue have been calculated at a depth of 0.07 mm in two right-angled circular cylinder phantoms made of 4-e lement ICRU tissue and irradiated by extended plane-parallel photon be ams of oblique incidence relative to the cylinder's main axis. The cyl inders were 30 cm in length and 1.9 cm or 7.3 cm in diameter, represen ting a finger or the lower arm. The calculations were performed by Mon te Carlo simulation of the energy transport of monoenergetic photons t hrough the phantoms as a function of energy and of the angle of incide nce. The angle was varied between 0-degrees and 90-degrees, the energy between 4 keV and 1.25 MeV. The results for monoenergetic photons hav e also been used to derive the corresponding conversion coefficients f or a variety of X ray beam qualities frequently employed in the proced ure for calibrating and type testing personal radiation protection dos emeters.