It as recalled that the rate theory of irradiation effects in crystalline solids rested upon a set of 2 ordinary differential equations which, for each type of point defect (vacancy and self-interstitial), described the balance between the production of defects and their annihilation. The latter occurred either via mutual recombination, a bi-molecular reaction or by elimination at point-defect sinks; a first-order reaction. The elimination rate was proportional to the product of the defect concentration, the defect diffusion coefficient and a geometrical factor (the so-called sink strength). The classical expression for sink strength was obtained by solving the diffusion equation for point defects in a cell which contained the sink, while ensuring that the mean value of the defect concentration in the cell equalled the concentration in rate theory. An alternative criterion was proposed hereSince the amplitude of the irradiation effects of practical relevance was governed by the partitioning of defect annihilation between mutual recombination and elimination at sinks, it was proposed that the value of the sink strength should give the correct value for the latter partitioning. These sink strengths, when scaled to their classical value, were evaluated for sink geometries of practical interest and were expressed as a function of a single dimensionless parameter which was a function of the irradiation flux and the temperature. Depending upon the irradiation conditions, the correcting factors for individual sink strengths could be large (several orders of magnitude). When several types of sinks competed, it was further supposed that the partitioning of elimination among the various types of sink had the correct value. These sink strengths were additive; unlike classical ones. According to the present scheme, the dislocation bias (which measured the relative difference between the sink strengths of dislocations for interstitials and vacancies) was shown to increase with the strength of neutral sinks around the dislocation. It ranged from zero, when dislocations were the only sinks, to several tenths when the neutral sinks had a strength which was much larger than that of dislocations. The estimation of the correcting factor was performed in a way such that it could be easily incorporated into the rate theory of irradiation effects.

Elimination of Irradiation Point Defects in Crystalline Solids - Sink Strengths. N.V.Doan, G.Martin: Physical Review B, 2003, 67[13], 134107 (11pp)