Angular distributions of relativistic ions channeled in the bent [formula omitted] Si crystals

Abstract

The angular distributions of relativistic protons channeled in the bent 〈1 0 0〉 Si crystals are considered. The ion energy is 7 TeV, the radius of curvature of the crystal is 49.8 m and the crystal thickness is varied from 0.1 to 0.5 cm (before bending), corresponding to the bending angle range from 0.02 to 0.1 mrad. The crystal thickness range under consideration corresponds to the reduced crystal thickness range from 2.1 to 10.35. The angular distributions of transmitted protons were generated by the computer simulation method using the numerical solution of the ion equations of motion, with the Lindhard's expression for the continuum interaction potential of the ion and the crystal. The results of the analysis show that the angular distribution has a periodic behavior for the reduced crystal thickness, Λ, smaller than about 5. For variable Λ larger than 5 the angular distribution is “frozen”, i.e. its shape does not change, and this is accompanied by a slow decrease of the number of transmitted ions as Λ increases.