The stress-driven migration of point defects to a crack

The elastic interaction energy between a crack tip and nearby point defects is derived and used to estimate the kinetics of migration of these defects in the stress field of a loaded crack. Explicit results are obtained for both the transient depletion of solute atoms from an initial constant concentration and the steady state loss of point defects to a crack during irradiation. In the latter situation the migrating defects can be either self-interstitials or vacancies, and attention is drawn to the fact that interstitials should be lost at the tip of the crack whereas vacancies should enter the crack across the surfaces behind the actual tip. (author)