The theory of the scattering-induced feeding-in in bent crystals
Abstract An analytical theory for the efficiency of scattering-induced transitions from a random to a channeled state (feed-in) in bent crystals is derived. The predictions from the theory are in good agreement with experiment and Monte Carlo simulations.
The limits of volume reflection in bent crystals
We show that theory predictions for volume reflection in bent crystals agree with recent experimental data. This makes possible to predict the volume reflection angle and efficiency in a broad range of energy for various crystals. A simple formula is proposed for volume reflection efficiency. We derive the physical limits for application of crystal reflection at high-energy accelerators where it may help beam collimation.
Detailed investigation of the channeling phenomena involved in bending of high-energy beams by means of crystals
Abstract Strong bending effects for 12 GeV/ c positive particles traversing 2–3 cm long silicon crystals are reported, and results for crystal bendings of 4, 20, and 52 mrad are presented. Bending efficiencies up to 20% are seen. A combination of axial and planar channeling is responsible for the effects observed. Computer simulations, based on binary collisions, can explain in detail the experimental findings, and also elucidate important channeling phenomena in the transition region between axial and planar channeling. For negative particles a weak bending effect, caused by doughnut scattering, is demonstrated. Interesting results for planar feed-in and dechanneling are found in an experiment where three detectors are placed along the crystal.