Focusing of a 1-GeV proton beam as it is brought into the channeling regime by a curved single crystal

The possibility of focusing high-energy particles by means of bulk capture of particles in the channeling regime is demonstrated experimentally. Protons with energies of 1 GeV, as they were bulk captured by the (111) plane of a curved silicon crystal from an angular interval with FWHM = 7.2 mrad at the exit from the crystal, had an angular divergence with FWHM = 1.6 mrad. The phase space of the beam of channeling particles in this case decreased slightly (by a factor of 1.8).