Emission of diamonds, leucosapphire, and KU-1 quartz in the range of 200-800nm excited by electron beams with a pulse duration of 0.5 and 12ns

The paper presents the results of Cherenkov radiation (CR) studies in various crystals excited by nanosecond and subnanosecond electron beams with an electron energy of up to 400 and 200keV, respectively. These studies are motivated by the need to develop and create calibrated sensors of runaway electrons for tokamak-type installations. The spectral and amplitude-time characteristics of the radiation of different specimens of diamonds, leucosapphire, and KU-1 quartz excited by the electron beams were obtained and compared. These crystals were chosen on the basis of their transparency in the ultraviolet region of the spectrum. CR was observed with a spectrometer. An increase in the radiation energy with decreasing wavelength was observed in synthetic diamonds of IIa type, leucosapphire, and KU-1 quartz. The amplitude-time characteristics of the radiation of crystals, including CR, were measured with a photodiode having a pulse response time of up to approximate to 80ps. In chemical vapor deposited high purity diamonds excited by both nanosecond and subnanosecond beams, an exciton radiation with a maximum at 235nm was observed. Results show that leucosapphire and quartz can be used to create detectors of electrons with energies above 200keV.