The explosive decomposition of heavy metal azides initiated by a laser pulse was studied experimentally over a broad range of action levels (from the threshold values to those exceeding the threshold ignition energy by a factor of 100) and in the time interval including the induction period, and rapid explosive decomposition, and the expansion of detonation products. The explosive glow and expansion dynamics of the decomposition products in air and vacuum were investigated, and the velocities of the explosive decomposition front, the compression pulse, and the expansion of the explosion products were measured. Based on the results obtained, the possibility of the occurrence of preexplosion phenomena is discussed and the mechanism of laser initiation of heavy metal azides is analyzed.

No abstract

No abstract

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 200 keV, 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 ≈80 ps. In chemical vapor deposited high purity diamonds excited by both nanosecond and subnanosecond beams, an exciton radiation with a maximum at 235 nm was observed. Results show that leucosapphire and quartz can be used to create detectors of electrons with energies above 200 keV.

No abstract