A Topologically Connected Multistrip Crystal For Efficient Steering Of High-Energy Beam

Multiple volume reflection has been recognized as an efficient method to steer high-energy particle beams for beam extraction or collimation. A multistrip silicon crystal has been designed, consisting in an array of mutually aligned 16 silicon strips to cause multiple volume reflection. The multistrip was fabricated from one individual wafer and given the shape of a topologically connected crystal, which proved to be the best configuration for alignment. Full characterization of such a crystal has been carried out. The crystal was extensively tested at the H8 CERN line with 400 GeV/c protons. Record deflection efficiency of (96.0 +/- 0.5)% for a mean deflection angle of (112.2 +/- 0.1) mu rad was obtained. Since the performance of volume reflection is energy dependent, a specific emulation code has been developed to predict multistrip behavior at various energies.