Upgrading the CERN PS Booster for SPS Multi-Pulse Filling and Antiproton Production

New demands of PS users, notably regarding an increase of SPS intensity and p production for the accumulator ring (AA), are being met through an improvement programme involving most of the PSB systems. Progress is reported under the headings (i) doubling the PSB repetition rate for SPS multi-pulse filling; (ii) vertical recombination of beams from 2 × 2 rings; (iii) conversion of the computer controls; and (iv) measures to consolidate peak performance and to go beyond. The programme required substantial modifications of PSB magnets and their power supplies as well as of timing and beam observation equipment, a capacity increase of the air cooling (and heating) system, and connection to a new computer interface carried out during a four-months´ shutdown. The provision of transverse damping systems (being installed) as well as of h = 10 cavities (under construction) are the major developments required for raising the beam intensity towards 3.1013 protons per pulse. All these PSB improvements are described and first results of commissioning are discussed briefly.