Status and Outlook for Heavy-Ion Accelerator Systems

There are five major heavy-ion centers constructed or funded worldwide; two additional centers are on the verge of being funded. Additionally, there are numerous smaller installations producing excellent science. Most installations aim at 10 MeV/u for the higher mass particles, and as high as possible for lighter ions. Berkeley and Dubna have reached or plan to reach relativistic energies for heavy ions. Studies and proposals for additional relativistic heavy-ion faccilities are pursued at least in five places. Altogether a very large effort is under way which is bound to leave a deep impression on basic science in the decade to come. There is an obvious energy gap in proposed facilities; namely, 30 - 150 MeV/u for high-mass particles. It is apparent that we should be searching for inexpensive magnets for high Bp in circular machines, or for very high, inexpensive electric gradients in linacs. This picture could be dramatically changed with a real breakthrough in ion source development. At least we should satisfy ourselves that we understand ion sources to the extent that we can predict their ultimate performance; only then can we produce optimum accelerator system designs.