ELECTRON AND POSITRON CHANNELING RADIATION FROM BERYLLIUM-OXIDE

We present experimental observations of planar and axial channeling ra diation emitted by relativistic electrons and positrons traversing a B eO crystal. Values of thermal vibration amplitudes are obtained, and f ound to be in agreement with those obtained by other methods, namely, x-ray and neutron diffraction. The standard channeling-radiation theor y matches correctly the observed radiation spectra when the particle i s channeled along principal planes. Some of the planes with higher Mil ler indices give radiation spectra that can only be explained by the c oupling of the particle wave function to neighboring axes or planes, o r by population redistribution within the band.