A special radio-frequency manipulation has been studied and successfully implemented at the CERN Proton Synchrotron for the first time. This technique aims at depleting a well-defined fraction of a continuous longitudinal beam distribution by creating a so-called barrier bucket. In addition to the intrinsic interest for its originality, this approach has an immediate application at CERN in combination with the Multi-Turn Extraction scheme. The combination of these two exotic techniques into a single, highly sophisticated process allows to dramatically reduce the beam loss at PS extraction, thus opening the door to the production of high-intensity proton beams for future fixed-target experiments at the CERN Super Proton Synchrotron.

A barrier bucket scheme is being considered to reduce losses during the Multi-Turn Extraction from the CERN Proton Synchrotron to the Super Proton Synchrotron for the fixed- target physics programme. For effective loss reduction, the extraction kicker has to be triggered during the gap at the time of the longitudinal barrier. Initial beam studies at injection energy and with low intensity beams allowed to fully qualify an existing wide-band cavity to generate one or multiple beam synchronous pulses per turn. Bunch-length stretching and shortening have been exercised with barriers moving in azimuth with respect to the beam. The encouraging results obtained at injection energy guided the implementation of a de-bunching manipulation at higher energy to move all bunches into a single barrier bucket. Beam measurements at a momentum of 14GeV/c, varying intensity and the width of the barrier, demonstrate that a quasi-constant longitudinal line density and an almost fully depleted gap can be achieved at highest intensities. The contribution summarises the results of the beam studies at high energy together with some observations related to the Multi-Turn Extraction.

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