Molecular dynamics simulation of primary radiation damage in vanadium and alloy V-4Ti

In the framework of the molecular dynamics method, simulation of the primary radiation damage in crystallites of bcc both V and alloy V-4Ti was carried out. The initial temperature of the crystallites was 700 K, which corresponds to the operating temperature of the alloy when used as the material of the first wall of a thermonuclear reactor. The interatomic interaction in V and alloy V-4Ti was described on the base of modern potentials of interatomic interactions which took into account the interaction of screened ions at small interatomic distances and allowed to simulate correctly radiation damage. The impact of the decay particle on the atoms of the simulated crystallites, as a result of which a cascade of atomic displacements was generated, was simulated by assigning a pulse to one of the lattice atoms, the primary knocked out atom. The main characteristics of atomic displacement cascades in simulated crystallites were calculated: the number of defects at different stages of cascade development, the size of the radiation-damaged regions, and an analysis of the estimation of the number, types and sizes of the surviving radiation defects in crystallites. The results obtained are compared for vanadium and alloy V-4Ti.