Determination of the Chapman- Jouguet Pressure of a High Explosive from One Single Test

Abstract

Instead of evaluating the data of the surface velocities of adjacent metal foils of different thicknesses with reference to the high explosive charge, the shock wave velocity in a plexiglass block from one firing for one charge type was measured as a function of distance. If the high explosive charge is large enough, for example 64 mm diameter and 100 mm long, then the shock wave induced in the plexiglass gives, over the first 15 mm, a shock velocity which correlates with the detonation pressure or Chapman-Jouguet pressure. With the resolution inherent in this technique, an enhanced velocity over the first few millimeters, which would correspond to a von Neumann spike, could not be detected.