High Intensity Proton Sources

Since the start of the Spallation Neutron Source project, the field of high intensity (in the mA range and above) proton linacs based on superconducting resonators is living a time of great interest. A large variety of possible applications (nuclear waste transmutation, spallation neutron production, energy amplifier, radioactive ion production, neutrino factories, etc.) prompted many studies and proposals of new machines with final energy ranging typically from a few tens of MeV to about 1 GeV; high power requirements and reliability issues introduced new kinds of problems in linac and resonators design. A “zoo ” of different superconducting cavity types, often evolved either from the electron or from the heavy ion SRF technology, is growing to cover the many different proposed applications, and triggering development in related high power couplers and fast tuners. During the last few years, high gradient resonators have been successfully prototyped in the full range of interesting beam energy, down to beta=0.1. The trend is to extend the SC sections of high current proton linacs to very low beta, taking advantage of the large acceptance of short cavities in order to increase linac reliability and, in some cases, to allow acceleration of deuteron beams. The construction of new, superconducting high intensity proton linacs is foreseen in the next future