INFLUENCE OF INITIAL DENSITY ON THE REACTION ZONE FOR STEADY-STATE DETONATION OF HIGH EXPLOSIVES

The laser interferometric system VISAR was used to investigate the detonation waves structure of pressed RDX, HMX, TNETB, and ZOX with different initial density. The experimental results are the surface velocity profiles of foils placed at the boundary between a HE sample and a water window. Critical initial densities ρc at which the reaction zone structure changes crucially were found: Von Neumann spike was recorded if the density was less than the critical value, otherwise monotone pressure increase in the reaction zone was observed. The ρc is equal to 1.72 g/cm3, 1.84 g/cm3, 1.56 g/cm3, and 1.71 g/cm3 for RDX, HMX, TNETB and ZOX respectively. The results obtained for RDX demonstrate that the ρc essentially depends on the sample structure and is determined not only by the HE particle size, but also by the pressing process. The results of this work can be explained by growth of the initial decomposition rate of an explosive with the increase of density if we assume that physicochemical transformations take place in a compression wave