Validation of new thermal scattering libraries for the moderation of epithermal neutrons in phantom materials

The investigation of neutron transport inside the human body is fundamental in the field of Neutron Capture Therapy. The moderation of neutrons inside soft tissue is usually modeled using specific phantom materials, that approximate the human body. We propose a series of neutron irradiation experiments (on NILE and VESUVIO) on three materials: the well-characterized polymethyl methacrylate (pMMA) and Polyethylene (PE), and poly hydroxyl methacrylate (pHEMA) with 40wt% absorbed water, an alternative material to be used as phantom for neutron dose calculation. To assess the number of moderated neutrons by each material, we will measure the induced activity of foils of materials that present high neutron absorption cross section, that will be placed on the side of the sample. Experimental results will benchmark our new models for thermal neutron transport in organic systems, based on the Average Functional Group Approximation.