Published online by Cambridge University Press: 13 November 2002
New experimental results of investigations of the interactions of an intense 4.3-GeV electron beam with an aligned single crystal are given in the case when the electrons travel close to the crystalline planes (110). The growth of low energy radiation yields with the intensity of the electron beam and the peculiar properties of the produced γ-quanta at their passage through a small collimator aperture were observed. Large angular asymmetry at the scattering of low energy γ-quanta, which is evidence of high polarization of the radiation, was also detected. These unexpected phenomena may be stimulated by strong correlations of atomic excitations in crystals. The obtained results will be of use for understanding of the properties of both the excited crystalline medium and the mechanism of intense radiation under these conditions and also for practical applications of the radiation.