Defects in Dislocations Produced by Focusing Collisions in f.c.c. Lattices

Abstract

It is assumed that a focusing collision of sufficiently high energy encountering a stacking fault area of an extended dislocation produces a Frenkel pair. This effect is thought to be important in radiation damage where primary knock-ons produce long range focusing collisions. The number of Frenkel pairs which are produced this way is calculated. Two effects are discussed in detail for Cu: (1) The enhancement of damage by enhanced production of Frenkel pairs if dislocations are present. It is shown that one can expect an appreciable enhancement of damage for heavily cold-worked material. (2) The pinning of dislocation motion. If one assumes that each Frenkel pair produced in a dislocation acts as a primary point, the theoretical result is in qualitative agreement with the experimental data on dislocation pinning by irradiation.