A Digital Computer Program for Computing Ion-Saturation Currents from a Plasma of Uniform Density in a Two-Dimensional Geometry

The shape of the surface from which ions are extracted is a major factor in determining the tractability of an ion beam for fine focusing. In duoplasmatron-type ion sources the extraction is made from a plasma, and the shape of the plasma surface has been difficult to define. The paper describes a computer program which both determines the shape of a plasma surface in a known extraction geometry with known current density at the surface and calculates trajectories of particles leaving this surface.