Application of a High-Speed Electronic Computer in Diffusion Kinetics

The Argonne electronic computer AVIDAC is applied in the numerical solution of ${\mathrm{\partial n/\partial t=\nabla }}^2{\mathrm{n-k}}_1{n}^2{\mathrm{-k}}_{2}n$ , which, with suitable boundary and initial conditions, represents the reaction kinetics of the one‐radical model used earlier by Fricke to describe the track effect in the radiation chemistry of a solution of a single solute. The fractional number of radicals combining with solute molecules is computed in terms of two dimensionless parameters that completely define the problem. Comparison with the formulas derived by using Jaffé's approximation method shows in most cases agreement to within 10% (though in some extreme cases only to within 50% to 80%), which indicates that Jaffé's method should give useful results in developing other aspects of diffusion kinetics.