• S. Hancock, C. Carli, J.F. Comblin, A. Findlay, K. Hanke, B. Mikulec
  CERN, Geneva

Since the CERN PS Booster cannot simultaneously provide the beam brightness and intensity required, the nominal (25ns bunch spacing) proton beam for the LHC involves double-batch filling of the PS machine. Linac 4, which is under construction, will eventually remove this restriction. In the meantime, the request for 50 and 75ns bunch spacings to mitigate electron cloud effects has lowered the intensity demand such that the Booster can meet this in a single batch without compromising beam brightness. Single-batch transfer means providing two bunches from each of three Booster rings and, in turn, that the bunch spacing is modified by the addition of an h=1 rf component to the h=2 in the Booster in order to fit the h=7 rf buckets waiting in the PS (whilst leaving one bucket empty for kicker purposes). Following the first experiments performed in 2008, the rf manipulations in the Booster have been refined and those in the PS have been modified to cope with single-batch beams. This latest work is presented for both the 50 and 75ns variants.