The contribution of high-density electronic excitations to defect production in Fe was studied. The irradiation of thin films with several types of particle having wide ranges of energy and mass was systematically studied at about 77K, and the electrical resistivity change was measured in situ as a function of particle fluence. For each type of irradiation, the defect-production cross-section was deduced from the resistivity change rate. From the experimental data, the contribution of electronic excitation to the defect production cross-section was obtained. It was found that the primary ionization rate described well the defect production behaviour in Fe, as induced by high-density electronic excitation.

Defect Production Induced by Electronic Excitation in Iron. Y.Chimi, A.Iwase, N.Ishikawa, T.Kambara: Nuclear Instruments and Methods in Physics Research B, 2002, 193[1-4], 248-52