A revolutionary collimation approach is being developed by the H8RD22 collaboration. The basic idea is to replace the amorphous jaws, which spread the beam halo in the whole solid angle, with bent crystals, which are able to deviate the halo particles in a given direction outside the beam core. Studies to investigate the bent crystal properties have been carried out over the past 2 years at the H8 beam line (CERN SPS) with a 400 GeV/c proton beam. The crucial result of these studies is the observation of the Volume Reflection effect, the coherent scattering of the whole beam on the crystalline planes which provides a small but very efficient (respectively, 14 μrad and 98% at 400 GeV/c) particle deflection. The high efficiency (which should increase at higher energy) combined with a large angular acceptance (～100 μrad) led to the development of multi-reflection systems to increase the deflection angle. Nowadays this system has reached the stage to be tested in a circular accelerator as a primary collimator to verify the effective collimation efficiency in a complex environment. The second phase of the LHC collimation could be the first application of this crystal based system.
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