Automatic computation of diffusion rates

Abstract

The equations for diffusion due to gravity, thermal, and concentration gradients in a multi-component, quiescent plasma are so complicated that the calculation of the diffusion rate(s) should be automated. I give an automated calculation scheme that utilizes the inherent reliability of computers in conducting repeated operations, but does not require simultaneous solution of many linear equations for each time step. In the first part of the scheme, the quadratic concentration dependence of the individual coefficients in Burger's diffusion equation is exploited to automate the computation of the numerical coefficients that multiply these concentrations.