Focusing beam of 1-GeV protons with volumetric capture to the mode of channeling by bent single crystal

The ability to capture particles to the channeling mode in a range of angles that are much larger than the Lindhard angle by a bent single crystal was demonstrated. The essence of this effect, the volumetric capture, is that the conditions of capture to the channeling mode for particles may arise in the body of a crystal in regions where the particle trajectories coincide with the tangent to a bent crystallographic plane or axis. Capture is possible for particles of the incident beam inside the entire angle between tangents to the bent plane within the limits of the crystal. It is shown that particles captured into the channeling mode from a wide angle interval have a narrower angular distribution at the output from a bent crystal. Protons with 1-GeV energy in volumetric capture by the (III) plane of a bent silicon crystal from an angular interval with FWHM = 7.2 mrad had an angular divergence at the output from the crystal with FWHM = 1.6 mrad. A reduction by a factor of 1.8 was observed in the phase volume of the beam of channeled particles.