Invited Review Article: Modeling ion beam extraction from different types of ion sources

Abstract

The applications of ion beams are manifold. In most systems, improved extraction of the ion beam from the ion source can help to increase the ion beam current or to improve the ion beam emittance. Real understanding of the complete system is required to achieve improvement of ion beam intensity or ion beam quality. Mathematically, the situation is described by a boundary value problem for the fields and an initial value problem for ion beam tracking. Whereas the boundary value problem is similar for different ion sources, the initial value problem to be solved depends on very specific ion source conditions. The influence of different parameters like particle density and temperatures on the discharge itself is important. For the case of ion beam extraction from an electron cyclotron resonance ion source, the problems of a suitable model will be discussed in detail. It will be shown that specific diagnostics are required to measure specific beam parameters. Such diagnostics are to be included in the simulation as well. The overall goal remains to develop a model that can be used for further improvements of beam intensity and quality from specific ion sources.