Depleted zone formation and recovery during neutron irradiation

Abstract

Seeger zones or depleted zones are believed to be responsible for increased hardening in neutron irradiated materials. This investigation is an attempt to calculate the density of the Seeger zones as a function of temperature, neutron flux, fluence and dislocation density. The calculations assume an initial zone size at creation and then follow the annealing behavior of the zone. The zone anneals by absorbing vacancies and interstitials and by emitting vacancies. The annealing rates are controlled by the concentrstion of vacancies and interstitials. These concentrations are in turn dependent upon the Seeger zone density. The point defect concentrations are determined from chemical reaction rate equations.