Dąbrowska, JoannaOlko, PawełSowa, UrszulaSwakoń, Jan2018-01-122018-01-122007http://rifj.ifj.edu.pl/handle/item/153The work is aimed at optimizing the proton beam spreading system at the IFJ PAN radiotherapy of ocular melanoma facility. Single scattering foil and double scattering foil systems have been investigated by Monte Carlo simulations. In the case of single scattering foil system dose distributions were uniform to within ± 1 % over a 4-cm-diameter region, whereas in the case of double scattering foil system the same uniformity was achieved in a region up to 3.6 cm in diameter, but its efficiency of dose rates was 5.7 times better. Since the total thickness of foils in the single and the double foil systems was equivalent, in both cases the energy loss was the same.polReport