Abstract <p>Electrostatic ion sources with different methods of plasma excitation are widely used in the production of high-tech products, the surface modification of which provides predetermined properties. These properties essentially depend on the parameters of the generated ion beams, which are determined by the correspondence of the ion-extraction system to the required application, in particular, the optimal design of the ion source as a whole, including the working medium consumption parameters. This work is devoted to solving the problem of optimizing the flow rate of the ion source. It is proposed to consider the integral discharge parameters of a radio-frequency ion source operating as part of a vacuum process facility. This approach makes it possible to ignore the spatial distributions of discharge plasma parameters and to propose a simple model for determining the optimal coefficient of the source mass efficiency. An example of a calculation is shown, which allows a preliminary estimation of the parameters of the process facility.</p>