Sensitivity of metallic materials under irradiation with swift heavy ions

We report on experimental results on metallic materials (Ag,Sn) after irradiation with swift heavy ions. These results, in addition to previous ones, show that the behaviour of that kind of materials could be well described in the framework of the thermal spike model. We find a good correlation between theoretical results and experimental ones provided that the only free parameter of the model should be known: the number z of electrons involved in the thermal spike mechanism via the electron phonon coupling constant. It is shown that the values of z must lie in the range of 1 and 2 electrons per atom. A simple criterion is deduced and used to know whether a given material could be sensitive or not to the electronic slowing down of swift heavy ions. (orig.)