Sources of beam halo formation in heavy-ion superconducting linac and development of halo cleaning methods

The proposed Rare Isotope Accelerator (RIA) Facility, an innovative exotic-beam facility for production of high-quality energetic beams of short-lived isotopes, will contain two superconducting linacs. To produce sufficient intensities of secondary beams the driver linac will provide 400 kW accelerated beams of any ion from hydrogen to uranium. A detailed design has been developed for the focusing-accelerating lattice of the RIA driver linac which is configured as an array of short SC cavities, each with independently controllable rf phase. To obtain high-power heavy-ion beams the driver linac uses simultaneous acceleration of multiple charge states and two strippers. End-to-end beam dynamics simulations in six-dimensional phase space were applied to study all possible sources of beam halo formation in the driver linac. The concept of a "beam-loss-free" linac is developed and implies beam halo collimation in designated areas.