Stress-induced diffusion of point defects to lenticular bubbles: Self-consistent calculations of the sink strengths

Abstract

The lenticular bubbles produced by neutron irradiation in boron carbide are secondary defects which induce very high local stresses presenting the same dipolar character as those induced by dislocation loops.

We have solved the problem of diffusion of point defects to lenticular bubbles by using an analytical calculation based on the effective-medium theory. The use of oblate spheroidal coordinates allowed us to replace the angular dependence of the elastic interaction energy which produces the drift of point defects to the bubble, by a step function. Then a self-consistent calculation of the sink efficiency can be carried to the end and the respective effects of the stresses and of the randomness of the defect distribution can be separated.