The microstructure evolution of a non-equilibrium system of primary defects was considered, in which mobile point defects, vacancy loops and sessile interstitial clusters were produced continuously by cascade damage irradiation. The stability of a spatially homogeneous microstructure was analyzed. It was found that in fully annealed metals the homogeneity may become unstable when the yield of vacancy clusters in collision cascades was sufficiently low. The bifurcation parameter and the critical wavelength of the developing heterogeneity were determined as a function of the damage rate, temperature, and clustering fractions of vacancies and interstitials. It was also found that the case of only vacancy loop generation does not correspond to the limiting case of low interstitial cluster production when vacancy loops and interstitial clusters were produced simultaneously.

Spatial Instability of a System of Primary Defects under Cascade Damage. A.A.Semenov, C.H.Woo: Journal of Physics D, 2001, 34[24], 3500-4