The effect of defect clusters formed in cascades on the sink strength in irradiated materials

Conference · Sat Sep 01 04:00:00 EDT 1990

DOI:https://doi.org/10.1016/0168-583X(91)95173-B· OSTI ID:6598569

Wiedersich, H

Defects produced by irradiation with energetic particles are most often spatially strongly correlated. Energetic primary recoil atoms produce generally more or less dense cascades in which vacant lattice sites predominate in the central regions, and interstitial atoms are deposited at the periphery. In fact, in many cases a fraction of the defects produced in the cascades form clusters during the cascade event. In this paper we examine the role of these clusters as defect sinks during high dose irradiations at moderate temperatures. It is shown that a steady state population of vacancy and interstitial clusters evolves during irradiation which significantly contributes to the overall sink density in the material. At sufficiently low temperature, i.e., at which thermal evaporation from vacancy clusters can be neglected, the steady state cluster density is characteristic of the primary recoil spectrum, but does not depend on temperature or dose rate. Consequently, contributions by migrating defects to irradiation-enhanced diffusion or to ion-beam mixing should also be temperature and dose-rate independent. When thermal evaporation of vacancies from small defect clusters becomes competitive with absorption of excess interstitials, the cluster population becomes temperature and rate dependent.

• Research Organization: Argonne National Lab., IL (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6598569
• Report Number(s): CONF-900936-3; ON: DE90017815
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360106* -- Metals & Alloys-- Radiation Effects
360206 -- Ceramics
Cermets
& Refractories-- Radiation Effects
360605 -- Materials-- Radiation Effects
CASCADE THEORY
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
INTERSTITIALS
IRRADIATION
MATERIALS
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
RADIATION EFFECTS
VACANCIES