When the particles beam interact with the nuclei of the target material, a nuclear reaction may occur. In this reaction, the two nuclei can fuse, forming a new element, which has a lot of energy, which decays by emitting particles and/or gamma radiation. The gamma radiation is characteristic of the formed nucleus, which allows the identification between the isotopes of one same element. From the identification of the formed core, it is possible to determine the original element belonging to the sample with which the incident beam has a nuclear ration.