A Proof of Principle of Asymmetric Bunch Pair Merging

Bunch splitting was established as a routine operation in the arsenal of rf gymnastics in the PS Complex long before it became the saving grace of the beam for the LHC. Historically, however, it was born out of the time-reversed analogue process of merging, in which a pair of bunches are combined. Hitherto, both operations have been performed with bunches of equal longitudinal emittance. Now an asymmetric merging process has been demonstrated. By combining a bunch with a small empty bucket, it is possible to deplete only the central density of the resultant particle distribution. This would allow bunches to be tailored with quasi-flat line densities. The details of the method are presented together with some measurements.