High-efficiency deflection of high-energy protons through axial channeling in a bent crystal.

  title={High-efficiency deflection of high-energy protons through axial channeling in a bent crystal.},
  author={Walter Scandale and V. M. Suvorov and Giovanni Ambrosi and Liudmila G. Malyarenko and Massimiliano Fiorini and A. Mozzanica and P. Zuccon and S. Hasan and Roberta Santacesaria and G. Cavoto and V. A. Maisheev and M. J. Prest and B. Bertucci and Paolo Valente and Yury A. Chesnokov and A. G. Afonin and Alberto Vomiero and A. S. Denisov and L. P. Lapina and William J. Burger and Yury A. Gavrikov and Sergey Vavilov and V. V. Skorobogatov and A. D. Kovalenko and Erik Vallazza and Davide Bolognini and Vincenzo Guidi and Claudio Luci and Gianantonio Della Mea and Yuri M. Ivanov and Andrea Mazzolari and I. A. Yazynin and Alexander M. Taratin and Pietro Dalpiaz and Riccardo Milan and Stefano Baricordi},
  journal={Physical review letters},
  volume={101 16},
Beam deflection due to axial channeling in a silicon crystal bent along the 111 axis was observed with 400 GeV/c protons at the CERN Super Proton Synchrotron. The condition for doughnut scattering of protons by the atomic strings of the crystal was attained. Such a condition allowed one to observe a beam deflection of 50 murad with about 30% efficiency. The contribution of hyperchanneled states of protons to the observed beam deflection was less than 2% according to simulation results.