Calculations involving ion beam source

A convergent numerical model for the calculation of the optical properties of an ion beam is given. The ion beam is formed by extracting ions from a plasma and subsequently accelerating these ions with an electrode system. The model includes the effects pf space-charge of the ions and an equilibrium distribution of electrons. Methods are given for determining the existence of the solution to the nonlinear difference equations, and a convergent iterative numerical procedure is described. Comparisons are made with a procedure that previously has been used to solve such a model