Evaluation of all dose components in the LVR-15 reactor epithermal neutron beam using Fricke gel dosimeter layers

Dosimetric evaluation in BNCT neutron beams are very challenging because of the presence of distinct radiation components having different biological effectiveness. Fricke gel dosimeters in form of layers are chemical dosimeters based on Fricke solution that are suitable to reconstruct bidimensional distributions of the absorbed dose; in accordance with their chemical composition and applying suitably developed algorithms, they can provide dose images due to the different radiation components. These dosimeters, based on tissue equivalent porcine skin gelatine, are shaped in form of layers (3 mm thick) and inserted in water equivalent phantoms. After the description of the applied method, this work presents the results obtained at the epithermal column of the BNCT facility at the Nuclear Research Institute of Rež (Czech Republic). The measured dose distributions are shown in comparison with data taken by means of other dosimeters (TLDs) and with calculations carried out with the Monte Carlo code MCNP5. Despite the not negligible uncertainties in parameters utilised for the analysis of the acquired images, the agreement with the results obtained by means of different techniques is satisfying.