Purpose. To develop a laser method for initiating a converging cylindrical front of a detonation wave and a method for calculating the kinematic parameters of the cylindrical shell walls, accelerated by the pressure of the detonation products of an external explosive charge. Methodology. An experimental technology for the manufacture of a photosensitive explosive composite and an experimental technique for igniting the surface of its layer with an extended laser beam without the use of a fiber-optic cable are used. The results of simulation modeling the Monte Carlo method were used to study the effect of illumination on the process of ignition of explosives by laser pulsed radiation. For the selected type of photosensitive explosive composite, its explosive and optical characteristics, the distance from the surface of the explosive charge to the lens scattering the laser beam, and taking into account the total area of the expanded beam, the regularities of the distribution of the radiation energy density over the vertical and horizontal sections of the laser beam were studied. Findings. The analysis of the scientific and technical level of methods of shock-wave processing of materials in the region of ultrahigh pressures from the point of view of the fundamental value of the cumulation of energy in the waves of a converging cylindrical detonation and shock front is carried out. Physicomathematical modeling was carried out and the regularities of pressure increase in the wave front were established in the process of approaching the shell walls to the axis. The scientific results of modeling converging cylindrical shells under the influence of the pressure of the explosion products have been analyzed. A method for laser initiation of a converging cylindrical front of a detonation wave has been developed, and a method for calculating the kinematic parameters of the converging walls of a cylindrical shell has been proposed. Originality. A technique has been developed for determining the energy characteristics of an expanded laser beam, calculating the laser radiation energy required to initiate detonation simultaneously on the entire lateral cylindrical surface of a photosensitive explosive composite. The idea of technical implementation of the cumulation of converging cylindrical detonation and shock waves was developed further. A technique has been developed for the numerical determination of the change in the internal average compression rate of the shell during the movement of its walls towards the axis for various ratios of its external radius to the wall thickness and taking into account the increase in pressure in the converging detonation front. Practical value. For the first time, a method for laser initiation of a converging cylindrical front of a detonation wave was developed and a device was tested that forms a converging cylindrical front of a detonation wave and a corresponding shock front in the material under study by the impact of a metal shell converging to the axis. The core of the device is a laser explosive initiation system that uses light-sensitive explosive composites to initiate an explosive charge.

The purpose of paper is to study physical and chemical patterns for starting detonation in the explosive charges by means of laser pulse radiation. Studies of the physical and chemical properties of the mechanism for stimulating the detonation of explosives by pulse radiation of an optical quantum generator have been carried out. Methodology of experimental and theoretical studies as well as mathematical modeling, involving gas-dynamics equations, has been applied. Basic research results as for studying sensitivity of the explosives being initiated by pulse light radiation have been analyzed. Numerical modeling was performed taking into consideration the real process of igniting the explosive by infrared laser radiation. The proposed mathematical model makes it possible to study the peculiarities of initiating the explosive transformation of bursting explosives by means of short light pulses. Tetranitropentaerytrite (PETN) was used to show that the process is determined completely by the parameters which characterize radiation intensity and absorption properties of the explosive. Depending on these parameters values, initiation processes may be implemented qualitatively – either on the surface or inside the explosive. In the latter case, the release of chemical energy results in the formation of so-called “chemical” pressure peak. With the use of lead azide, it has been shown experimentally that the initial temperature does not affect the increase in explosive sensitivity even in case when laser radiation takes place in the nanosecond pulse mode. Experimental results are applied while developing light-sensitive composites with the preset explosive and physical-chemical properties. The determined patterns were used in the development of the light-sensitive explosive composites for blasting agents of explosive charges.