SEDL / STP / STP1405-EB / STP10573S

Molecular Dynamics Simulation of Radiation Damage Production in Cubic Silicon Carbide

Malerba, L
professor and student, Instituto de Fusión Nuclear, ETSI Industriales, Universidad Politécnica de Madrid, Madrid,

Perlado, JM
professor and student, Instituto de Fusión Nuclear, ETSI Industriales, Universidad Politécnica de Madrid, Madrid,

Pastor, I
professor and student, Instituto de Fusión Nuclear, ETSI Industriales, Universidad Politécnica de Madrid, Madrid,

Diaz de la Rubia, T
Manager scientist, Lawrence Livermore National Laboratory, Livermore, CA

Pages: 13    Published: Jan 2001

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Abstract

Silicon carbide (SiC) is a candidate material for nuclear fusion reactor blankets; hence the importance of investigating its response to irradiation. Molecular dynamics (MD) simulations are a powerful tool to study radiation-damage production from the microscopic standpoint. Results of displacement-cascade MD simulations, conducted using the Tersoff potential to describe the interatomic forces, are presented herein. The number of point-defects produced in the material by silicon- (Si) and carbon- (C) primary knock-on atoms (PKAs) of increasing energy (between 0.25 and, respectively, 8 and 4 keV) is studied systematically. By comparison with standard theoretical models, threshold-displacement-energy (TDE) values of practical usefulness for SiC are derived. The effect of irradiation temperature is also allowed for. Qualitatively, the C sublattice turns out to be more heavily damaged than the Sisublattice. The effect of the irradiation temperature becomes visible only above ≈2000 K.