Mechanisms of 200 MeV electron radiation in diamond crystal in the axial orientation

The γ-radiation by electrons with the energy of ∼200 MeV in a 100μm-thick diamond crystal has been measured at the MAX-lab experimental facility, when the electrons are incident on the crystal along the 〈100〉 axis. In this case, the intensity of the -radiation with the energy ∼1-2 MeV is approximately 16 times higher than that in amorphous matter of the same thickness. Theoretical calculations based on the quasi-classical QED approximation are in good agreement with the experimental data. The analysis of the radiation mechanisms has shown that the main contribution to the radiation intensity resulted from electrons, moving in the above-barrier regime and at small angles to the crystal axis.