Present Performance of the CERN 800 MeV PS Booster (PSB)

The CERN 800 MeV PSB consists of four synchrotrons stacked one on top of the other. The injector is the present 50 MeV CERN Proton Synchrotron (CPS) linac. Its beam is injected sequentially into the four rings via a vertical distribution system. Monoturn or multiturn injection of up to fifteen turns is available. After acceleration to 800 MeV, the four beams are ejected sequentially and brought to a common level by a recombination system. All twenty bunches are then transferred to the CPS, thus potentially increasing its intensity to 1013 p/p. Construction started in 1968, running-in on 1 May, 1972. Experiments on injection, acceleration, and transfer to the CPS were carried out whilst completing the installation of beam observation systems, debugging the interface to the IBM 1800 control computer, and bringing the software to operational standard. Closed orbit deviations are less than anticipated (only a few mm). Linear coupling and sum resonances were studied with a beam coasting at injection energy: they can be compensated with a small fraction of the available correction strength. Multiturn injection, RF trapping efficiency, acceleration, synchronization, ejection, and transfer to the CPS are described in their latest stage. At the end of the year the design intensity of 2.5 × 1012 p/p was reached in one ring.