Diffusion-controlled annihilation A + B → 0 with initially separated reactants: The death of an A particle island in the B particle sea

الأصل · EN

We consider the diffusion-controlled annihilation dynamics A+B→ 0 with equal species diffusivities in the system where an island of particles A is surrounded by the uniform sea of particles B. We show that once the initial number of particles in the island is large enough, then at any system's dimensionality d the death of the majority of particles occurs in the universal scaling regime within which ≈ 4/5 of the particles die at the island expansion stage and the remaining ≈ 1/5 at the stage of its subsequent contraction. In the quasistatic approximation the scaling of the reaction zone has been obtained for the cases of mean-field (d ≥ dc) and fluctuation (d < dc) dynamics of the front.