Some comments on space charge neutralisation of positive and negative ion beams

The importance of space charge forces in determining the transport of high current ion beams in neutral injectors has been stressed by Gabovich and more recently by Holmes. Both Gabovich and Holmes presented models which expanded on earlier treatments, although they differed from each other in many respects. In this note we consider the relations between these treatments and that based on the work of Dunn and Self on neutralisation of electron beams, and the applicability to problems encountered in injector design