Automatic longitudinal tuning of a multiple-charge-state heavy-ion beam

A new procedure has been developed for automatic longitudinal tuning of a multiple-charge-state heavy-ion beam. It uses a matrix-based code to track the beam centroids and Twiss parameters of the individual charge state beams and a minimization code to minimize a goal function by adjusting the synchronous phases and field levels in the accelerating cavities. The procedure has been successfully tested in the case of the Rare Isotope Accelerator driver linac and proven to improve an original manual tune by significantly reducing beam losses. The procedure was also applied for fast retuning of the linac after one or more cavity failure and restoring the beam with limited beam loss.