Characterization of the Detonation Pressure of a PETN Based PBX with the Optical Active Method

Abstract

Detonation metrology is essential for the development of energetic materials, to characterize existing explosives, and to characterize materials behavior under high pressures. The optical active method (OAM), based on PMMA optical fibers (250 μm diameter) and their radiation transmission loss when shocked, was used to characterize the detonation wave (DW) and shock wave (SW) in inert barriers and applied to measure the detonation pressure in condensed explosives. The detonation velocity and detonation pressure of a PBX based on PETN (86 % PETN, 14 % Sylgard), known as Seismoplast were measured. The OAM with protected optical probes (POP) was used to determine the mean detonation velocity (7337 m s À 1 ), whereas the OAM with bare optical probes (BOP) was used to measure the induced shock velocities generated by Seismoplast on different thicknesses of PMMA (1-9 mm), aluminum and copper (1-7 mm). Based on the shock velocities at the interfaces between the explosive and the inert barriers, the CJ pressure of Seismoplast was determined as 21.2 GPa.

Detonation characterization of low‐density emulsion explosives

“…This was made by the identification of the time that the shock wave needed to pass through each of the optical fibres embedded in the PMMA. The choice of using PMMA as the inert material relied on the fact that the Hugoniot constants are known, and its density ($${{\rho }_{{0}_{PMMA}}}$$ =1.186 g/cm 3 [42, 48]) is relatively similar with the reference EE used (without EPS). In order to describe the displacement of the shock wave in the PMMA barrier, a quadratic trend line fitting was performed on the experimental points.…”

“…The Hugoniot constants values $${{C}_{0}}$$ and $${s}$$ are, 2598 m/s and 1.516, respectively [42, 48].…”

“…Two explosive charge configurations were used during this work, rectangular and circular, both were initiated with a number 8 detonator followed by a standard emulsion. Detonation velocities were measured by a discrete method in the rectangular cross-section charges whereas detonation velocities and pressures were determined by quasi-continuous metrology, as opposed to other authors who used a discrete registration method, to identify the detonation velocity [40,41] and the propagation of the shock wave in an inert material [42,43].…”