Assessment of the tandem method using OSL dosimeters for ICRU 95 operational quantities

The International Commission on Radiation Units and Measurements (ICRU) in the ICRU report 95 defined a new set of operational quantities for radiation protection. These quantities replace the operational quantities defined in ICRU Report 39/51 used for measuring personal and area monitoring. Since 2022, the impact has been accessed for various types of monitoring systems. For individual monitoring of whole-body doses of photons, the use of the ICRU 95 quantities, theH_P, result in an overestimation of radiation doses of up to 5 times for low energy photons, directly impacting doses measured in medical applications. Currently, it has not been demonstrated that single-element or double-element dosimeters using different filters over the sensitive elements are able to measureH_P. Therefore, this work investigates if it is feasible for a new type of all-optically stimulated luminescence (OSL) dosimetry system, composed of two OSL materials, magnesium tetraborate doped with cerium, lithium and gadolinium (MgB₄O₇:Ce,Li,Gd) and beryllium oxide (BeO), to measure ICRU 95 operational quantities for photons. The results demonstrate that the useful range for energy discrimination from the tandem curves starts at higher energies (83 keV). Therefore, the tandem method applied to doped-MgB₄O₇and BeO is limited to the identification of low/high average energy and cannot be used to correct the low energy dependence observed in the ICRU 95 operational quantities for photons.