Electromagnetic radiation of relativistic electrons in thick crystals

Angular distributions of soft gamma quanta and electron radiation intensity spectra in diamond crystals of different thicknesses under conditions of axial orientation are compared. Narrow directivity of soft gamma radiation and weak dependence of distribution width on crystal thickness is noted. In case of axial orientation the angular width of soft gamma quanta distribution for diamond, silicon, tungsten crystals constitutes ΔΘγ ∼ ± 2ΨL, where ΨL=0.43; 0.42 and 1.47, accordingly. Radiation losses to a collimator ΘK=1/γ on axial orientation grow with thickness increase and reach a maximum value at t∼0.1 radiation lengths. It is experimentally shown that maximum values of radiation losses to cone γ-1 can be obtained in light element crystals