Target theory applied to swift heavy ions track grafting experiments

Part of the damage induced in polymers by heavy ion irradiations consists in chain scission, free radicals formation and many excited molecules. The active sites along the polymer chains so produced can be used to initiate grafting reactions. Betz, obtained results in swift heavy ion (SHI) track grafting of styrene monomers onto poly vinylidene fluoride (PVDF) films, comparing the grafting yield as a function of the fluence for different ions while Butts and Katz developed a target theory that allows to predict the response of different substrates to heavy ions irradiations (i.e. dry enzymes and viruses, nuclear emulsions, scintillation counters, the ferrous sulphate dosimeters and solid state nuclear track detectors). In our work we postulate a non-active zone for grafting around the ion incidence axis. This non-grafting zone allows the experimental results obtained by Betz to be approximated by the target theory. A good agreement is obtained between experimental and theoretical values using the characteristic γ-ray dose D γ and the non-grafting dose, D 0 as parameters.