Radial distribution of dose within heavy charged particle tracks – Models and experimental verification using LiF:Mg,Cu,P TL detectors

• Innovative method of experimental verification of RDD models has been proposed.
• The method was tested for 9.3 MeV/n 131Xe ions and three different RDD models.
• Up to 104 Gy the analyzed models present good agreement with experimental data.
• Probability of occurrence of doses >104 Gy within particle track is relatively low.
• Newly proposed method gives results consistent with experimental data within 15%.

A new method of experimental verification of radial dose distribution models using solid state thermoluminescent (TL) detectors LiF:Mg,Cu,P has been recently proposed. In this work the method was applied to verify the spatial distribution of energy deposition within a single 131Xe ion track. Detectors were irradiated at the Department of Physics of the University of Jyväskylä, Finland. The obtained results have been compared with theoretical data, calculated according to the Zhang et al., Cucinotta et al. and Geiss et al. radial dose distribution (RDD) models. At the lowest dose range the Zhang et al. RDD model exhibited the best agreement as compared to experimental data. In the intermediate dose range, up to 104 Gy, the best agreement was found for the RDD model of Cucinotta et al. The probability of occurrence of doses higher than 104 Gy within a single 131Xe ion track was found to be lower than predicted by all the studied RDD models. This may be a result of diffusion of the charge, which is then captured by TL-related trapping sites, at the distances up to dozens of nanometers from the ionization site.