Island embryo regression driven by a beam of self-ions in the linear regime

The kinetics of island growth and regression are discussed under the approximation of linear response, including the Gibbs-Thompson potential, for a reacting assembly of adatoms and advacancies (thermal defects) on a surface irradiated with a beam of self-ions. First the quasistatic growth or shrinkage rate, for islands of size n less than the critical size n-hat, is calculated for the driven system, exactly, for linear response. This result is employed to determine successively: (i) the regression rate of driven embryo islands with n < n-hat; and (ii) the structure of the steady state decay chain established when embryos of a particular size n0< n-hat are created by ion beam impacts. The changed embryo distribution caused by irradiation differs markedly from the populations of the embryos at equilibrium.