A proposal to test beam extraction by crystal channeling at the SPS : a first step towards a LHC extracted beam

Abstract

The availability of a beam extracted out of the LHC accelerator would open up very interesting possibilities for B-physics, in particular for the study of CP-violation. Channeling in bent crystals appears to be the most promising method to produce an extracted beam of intensity 10**8 protons/s. This would provide as many as 10**10 B-Bbar pairs per year of run, i.e. two orders of magnitude more than could be produced by an e+e- B-factory with a luminosity of 10**34 cm-2 s-1. We propose an R&D programme to study beam extraction at the CERN SPS, using a bent crystal to be installed in the SPS beam pipe and placed next to the beam in such a way as to intercept the beam halo. Transverse excitation of the beam in the presence of non-linearities will be used to create halo conditions similar to those expected for the LHC.