Defect production induced by electronic excitation in iron

The contribution of high-density electronic excitation to defect production in iron has been studied. Irradiations of iron thin films with several kinds of particles in the wide energy and mass ranges are performed at ∼77 K systematically, and the electrical resistivity change is measured in situ as a function of particle fluence. For each irradiation, defect production cross-section is derived from the resistivity change rate. From the experimental data, we extract a contribution of electronic excitation to the defect production cross-section. The primary ionization rate well describes the defect production in iron induced by high-density electronic excitation