Calculation of WER values of some dosimetric plastic materials applied at helium ion beam therapy

In this research, water equivalent ratios (WER) at helium ion beam energy ranging 25-250 MeV/u for four potential plastic dosimetric materials: polycarbonate (PC), polypropylene (PP), polymethyl methacrylate (PMMA), and paraffin have been calculated using MCNPX Monte Carlo code. Among studied materials, PC and PP with 0.979 and 1.177 show minimum and maximum differences with water respectively. In mentioned materials by increasing mass density, WER values increase and by decreasing mass density they decrease. Calculated values are in good agreement with the results published in literatures.