The use of the Monte Carlo simulation technique for the design of an H*(10) dosemeter based on TLD-100

The thermoluminescence (TL) detector material LiF:Mg,Ti (TLD-100) and appropriate filter materials were combined in order to design a passive dosemeter measuring the operational quantity ambient dose equivalent, H*(10), for monitoring low-dose external photon radiation fields. Using the Monte Carlo simulation technique optimisations of energy dependent conversion coefficients from air kerma free-in-air compared to ICRU and ISO proposed values, h*k(10), were performed by varying dosemeter detector positioning, geometrical arrangements, and filter materials. Deviations smaller than 5% compared to h*k(10) between 30 keV and 2.5 MeV of primary photon energies were achieved by a dosemeter design consisting of a 15 μm Sn metal layer and a 5 mm PMMA layer surrounding the LiF detector. Subsequently performed free-air verification experiments carried out in well defined standard photon radiation fields showed an obviously TL-specific effect. An underestimation up to -15% of the modelled data at low photon energies was observed. (author)