DIFFUSION OF VACANCIES IN IRON-SILICON UNDER IRRADIATION WITH FAST NEUTRONS

The magnetic secondary effects of iron with 3% silicon permits a study of the production and diffusion of vacancies. Without irradiation, these investigations must be carried out over a long period of time. In addition to the thermal vacancies, other vacancies are produced by irradiation in a reactor. Over 400 deg C the thermal vacancies predominate, and the self-diffusion constant shows the usual increase with temperature. Under 400 deg C, the vacancies produced by the radiation effects predominate. An equilibrium exists between production and annihilation of the vacancies which leads to a temperature independent self-diffusion constart. Under 280'C the self-diffusion constant decreases since here the equilibrium between production and recovery is still not established. (tr-auth)