The simultaneous diffusion of the members of a radioactive series was analyzed. The diffusion equations took account of the radioactive production and decay of each of the members, and included the effect of radioactive recoil for a decays. Hydrodynamic coupling between several isotope fluxes was not considered. The diffusion equations were solved in spherical coordinates for general initial and Dirichlet boundary conditions. The solutions were applied to the effect of a recoil upon disequilibrium between 5 initial isotopes of the U series.

Simultaneous Diffusion of Isotopes from a Radioactive Series in Homogeneous and Isotropic Solids. F.B.Ribeiro: Radiation Measurements, 1998, 29[1], 9-18