Optimization of fiber optic probe for measuring detonation velocity

Abstract

Detonation velocity is one of the basic parameters for the characterization of explosives. One of the possible methods of obtaining the velocity is the use of a fiber optic probe. In principle it is an optical fiber which has perforated insulation and core to such an extent that it can absorb light perpendicular to the fiber but, still retains the capability of transporting light without a significant loss of intensity. Such fiber placed parallel to the explosive´s axis inside or at its surface will send light signals in defined intervals as the detonation front passes along the perforations. This study investigates how different diameters, depths and number of the perforations affect the signal quality. Applicability of this technique to different types of explosives is discussed. With the right combination of diameter and depth, measurements with 50 perforations on a single fiber are possible, allowing this technique to track changes in detonation velocity along the charge.