**2.1 Irradiation conditions**

The Ni22at%Si was prepared by solidification in an inert atmosphere furnace, the alloy was templated from melting temperature to room temperature in water. The irradiation targets were obtained by electroerosion with the next geometrical characteristics: alloy circular plates with an area of 1 cm<sup>2</sup> and thickness of 300 μm. Prior to being irradiated the plate's thickness was reduced to 100 μm to a mirror finish by mechanical polishing. The irradiation conditions used to bombard the alloy circular plates were Ni ions beam of 3.66 MeV at 650° C, the incidence angle of the ion beam to the surface was 90°, two different ion fluence of 3.97 × 1016 and 1.99 × 1017 ions/ cm2 were used to evaluate the irradiation time effect. It was used a pyrometer focused on the irradiated area, with a tolerance of ±10°C to perform the temperature control of the irradiated area. The irradiation was performed in a Tandetron-type GIC linear accelerator, designed to provide a large flow of ions 1.9 × 1017 ions/cm2 [11].
