Radiation in diamond, leucosapphire, and quartz under the excitation of electron beam with an energy of up to 400 keV

The paper presents measurement data on the radiation excited in synthetic diamonds, leucosapphire, and quartz KU1 at a wavelength of 200–800 nm by a pulsed electron beam with an energy of up to 400 keV. The crystals reveal wide bands whose intensity increases with decreasing wavelength in the range 220–400 nm. For leucosapphire and quartz, the radiation pulse at these wavelengths is close in duration to the electron beam current pulse, suggesting that it is Cherenkov radiation. For synthetic diamonds, both Cherenkov radiation and pulsed cathodoluminescence are detected in this spectral region. In particular, an intense band of free excitons with its maximum at 235 nm is found at high beam current densities and electron energies.