BeOSL dosemeters and new ICRU operational quantities: Response of existing dosemeters and modification options

摘要

The energy response for angles of incidence of 0 degrees and 60 degrees of current BeOSL H-p(10)-, H-p(3)-, H-p(0,07)and H*(10) dosemeters for photon radiation has been expressed in terms of the new operational quantities Hp, Dlens, Dlocal skin, and H* proposed by ICRU. Results show the H-p(3)and H-p(0,07) dosemeters can be used for Dlens and Dlocal skin with minor modifications to the system calibration. The whole body H-p(10) and area H*(10) dosemeters, however, show a pronounced over response in terms of the new quantities H-p and H* in the energy range below 40 keV. For the whole body dosemeter, we have investigated, by means of Monte Carlo simulations, how the use of different filter materials with higher Z(eff) and higher density could improve the response of the single element dosemeter in terms of H-p and identified filters that could achieve an IEC 62387 compliant response down to approximately 20 keV photon energy, assuming current IEC limits. In an alternative approach, a two-element algorithm, making use of the reading of the H-p(0,07) element of the dosemeter has been developed, which delivers a H-p-response fulfilling current IEC limits down to 15 keV, albeit with increased measurement uncertainty.