Spectral and amplitude-time characteristics of Cherenkov radiation upon excitation of transparent materials by an electron beam

Interest in the study of the characteristics of the Vavilov–Cherenkov (VCR) radiation has increased in connection with the work on the creation of runaway electron (RE) detectors for TOKAMAK-type installations. This review presents the results of studies of the spectral, amplitude-temporal, and spatial characteristics of VCR, obtained mainly in recent years when transparent substances are excited by an electron flux with energies of tens to hundreds of keV. The VCR spectra in diamond (natural and synthetic), quartz glass, sapphire, leucosapphire are given, and the VCR registration in MgF$_2$, Ga$_2$O$_3$ and other transparent samples is reported. A comparison of the spectra and amplitude-time characteristics of the VCR and pulsed cathodoluminescence (PCL) at various electron energies is carried out. For a number of samples, the VCR spectra were calculated taking into account the dispersion of the refractive index, as well as the energy distribution of the beam electrons and the decrease in the electron energy during their deceleration in the sample material. The emission spectrum of polymethyl methacrylate (PMMA), which is used as a material for radiators in Cherenkov detectors and optical fibers transmitting radiation in scintillation dosimeters, as well as a plastic base in organic scintillators, has been investigated.