Molecular dynamics studies of defect production and clustering in energetic displacement cascades in copper

Conference · Mon Mar 09 04:00:00 EST 1992

OSTI ID:10131034

Phythian, W J ^[1]

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1. AEA Technology, Harwell (United Kingdom)

We review recent molecular dynamics studies of displacement cascades in copper at energies from near threshold to 25 keV where nascent subcascades develop. We discuss the structure of the cascade region and present results on the dynamical evolution and lifetime of the cascades. We show that the defect and production efficiency in cascades follows a downward trend with energy, in good quantitative agreement with experiments. The cluster size distributions from the simulations show a strong recoil energy dependence. At low energy, loosely correlated vacancy distributions are generally observed. However, as the energy and hence the lifetime of the cascade increases, large vacancy clusters appear. Evidence is presented for the athermal collapse of a 25 keV cascade to a vacancy dislocation loop. Interstitial production mechanisms are identified. At all energies studied replacement collision sequences are observed. Moreover, vacancy-interstitial separation mechanisms based on ballistic clustering and dislocation loop punching from cascades are presented.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10131034
• Report Number(s): UCRL-JC--109396; CONF-911111--38; ON: DE92009683
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700480
CASCADE THEORY
COMPONENT DEVELOPMENT
COMPUTERIZED SIMULATION
COPPER
CRYSTAL DEFECTS
DISLOCATIONS
DYNAMICS
M CODES
MATERIALS STUDIES
NEUTRONS
PHYSICAL RADIATION EFFECTS
STRUCTURE AND PHASE STUDIES
THERMONUCLEAR REACTOR MATERIALS
VACANCIES