Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Determination of the Angle of Divergence of the Shock Wave of an Electric Explosion of a Flat Ring Foil in Air A.L. SURKAEV, D.A. KANTSEDALOV, V.I. USACHEV In the present work, by analyzing the results of experimental studies, the value of the divergence angle of the front of a shock wave (SW) generated by an electric explosion of a flat annular foil (EЕFRF) in an air atmosphere was estimated. The exploding annular foil, the discharge current through which flows in the radial direction from the center to the periphery, forms a shock wave in space with a pronounced directionality. The technique for determining the angle of divergence of the shock wave is based on recording the moment of opening of the system of photocells located linearly on the inner surface of a hollow cylinder and illuminated by laser radiation. In the initial state, the photocells are closed with opaque lowinertia petals, which are set in motion under the action of an air pressure pulse. Electrical signals are recorded by electronic storage oscilloscopes. As a result of the studies carried out, the value of the divergence angle of the front of a shock wave (SW) generated by the explosion in air of a flat annular aluminum foil (Al) of specific geometric parameters and the input energy was determined W ≈ 3,8 kG. Keywords: electrical explosion of conductors, flat annular foil, shock wave, wave front speed, photodiode system, divergence angle. DOI: 10.25791/pribor.1.2021.1232 Pp. 09-14.