Synchrotron injectors based on high charge state ion sources.

摘要

The performance of any injector contemplated to replace the electrostatic tandem accelerators some time in the future should evidently match or surpass the characteristics of the tandems. It is a fortunate coincidence that the performance of the BNL tandem satisfies in most respects the requirements of the proposed collider, although originally tandems were not built with this application in mind. Requests for heavy ion beams with parameters suitable for injection into the rings of a heavy ion collider have appeared rather recently, at a stage when the high charge state ion sources, which in principle are capable of producing many ion species, have not yet reached such a level of performance. Therefore, consideration of such sources as part of a future injector replacing the tandem accelerators will have to rely on the extrapolation of results from existing models, developed for a different purpose. At the same time, present and future collider requirements for heavy ion beams should serve as a stimulus for the development of sources producing ions with adequate charge states and intensities. Injectors based on such sources may present a better alternative than the tandem accelerators because a higher charge-to-mass ratio of ions from the source results in a more efficient and less costly accelerator. In this report, two candidates for a high charge state, heavy ion source will be considered: an EBIS and an ECR. Other approaches, e.g. laser ion sources, are much further away in the development of a device to be used in a synchrotron injector. 25 refs., 7 figs., 4 tabs.