Orientation effects in the incoherent bremsstrahlung by high energy particles in a crystal

A simulation procedure based on a semiclassical description of the bremsstrahlung process in crystals is developed. Using this procedure it is demonstrated that the intensity of hard incoherent radiation possesses substantial orientation dependence, when the particles are incident to crystallographic axes or planes at angles close to the critical channeling angle. It is demonstrated that the orientation dependences for the electrons and positrons substantially differ from each other. The orientation dependence on the crystal thickness is also considered. The results of simulations are in a good agreement with the experimental data.