Computer simulation of primary damage creationin high-energy displacement cascades in copperI. Defect creation and cluster statistics
- University of Liverpool
- ORNL
Atomic-scale computer simulation has been used to investigate the primary damage created by displacement cascades in copper over a wide range of temperature (100 K T 900 K) and primary knock-on atom energy (5 keV EPKA 25 keV). A technique was introduced to improve computational efficiency and at least 20 cascades for each (EPKA,T) pair were simulated in order to ensure statistical reliability of the results. The total of almost 450 simulated cascades is the largest yet reported for this metal. The mean number of surviving point defects per cascade is only 15-20% of the NRT model value. It decreases with increasing T at fixed EPKA and is proportional to (EPKA)1.1 at fixed T. A high proportion (60-80%) of self-interstitial atoms (SIAs) form clusters during the cascade process. The proportion is smaller for vacancies and sensitive to T, falling from 30-60% for T 600 K to less than 20% when T = 900 K. The structure of clusters has been examined in detail. Vacancies cluster predominantly in stackingfault- tetrahedron-type configurations. SIAs tend to form either glissile dislocation loops with Burgers vector b = 1/2<110> or sessile faulted Frank loops with b = 1/3<111>. Despite the fact that cascades at a given EPKA and T exhibit a wide range of defect numbers and clustered fractions, there appears to be a correlation in the formation of vacancy clusters and SIA clusters in the same cascade. The size and spatial aspects of this are analysed in detail in part II [26]. The stability of clusters when another cascade overlaps them is also investigated in part II.
- Research Organization:
- Oak Ridge National Laboratory (ORNL)
- Sponsoring Organization:
- SC USDOE - Office of Science (SC)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 958783
- Journal Information:
- Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: 2 Vol. 377; ISSN 0022-3115; ISSN JNUMAM
- Country of Publication:
- United States
- Language:
- English
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