Ion Injectors for High-Intensity Accelerators

Abstract

With a growing number of applications for ion accelerators, and a growing demand for high ion intensities, often coupled with increasing complex requirements, the ion injector can play a crucial role for the success of such projects. First there is the ion source that has to produce the desired ion specie, with the large variety of desired species requiring vastly different ion sources. In addition, the ion source has to produce those ions with the desired rate and without debilitating impurities, as well as with the desired duty factor. Several examples will show very successful ion sources to become useless when the duty factor is increased because the lifetime and or availability can change drastically. Equally important is the extraction of those ions and their transport to the next stage of acceleration because the slow ion velocities impose a serious challenge to increasing the intensity. As the beam intensity is increased, its emittance, stability, and controllability become increasingly important. This paper cannot cover this subject in depth. It tries to give a flavor of the complexities and to serve as an introduction to further reading and studies.