Mach Reflection of Detonation Waves in Condensed High Explosives

By preshocking a condensed high explosive before the passage of a detonation front, it is possible to increase the peak pressure in the front to a level at which reflection phenomena can be readily observed by means of the Dautriche effect. Also, by the use of a tracer detonation wave, which intersects the shock configuration, it is possible to observe the oncoming detonation shock, the reflected shock, the Mach stem, and their intersection in a triple point. This method has been used to obtain strong evidence for the existence of Mach reflection of detonation waves in a preshocked explosive (RDX). The transition from regular to Mach reflection for an estimated 50-kbar precompression shock occurs discontinuously at a critical angle of 44.5° ±2° and quite rapidly, often in less than 3 × 10−8 sec.