Detonation simulant of TATP as a donor charges in a detonation train

Abstract. Dual-use substances or those used to synthesize known homemade explosives (HME) are subject to strict controls. However, tertiary explosives are typically not classified as explosives under international regulations due to their exceptionally low shock sensitivity and non-ideal characteristics. Their ready availability raises significant concerns for counter-terrorism efforts, especially when they are used in conjunction with relatively small charges of HME as booster charges. Assessing this issue is challenging because data on the detonation properties of the donor charge and the shock sensitivity of the acceptor charge are often lacking. Most studies on HMEs primarily focus on synthesis, sensitivity, and overall performance, while the examination of tertiary explosives necessitates the use of large donor and acceptor charges. Due to the very high sensitivity of most HMEs, the synthesis, shaping and safe handling of kilogram-scale HME charges are moreover extremely complex. To circumvent these challenges, this work aims to develop simulation booster charges composed of diluted secondary explosives with detonation properties closely resembling those of the HMEs under consideration, such as triacetone triperoxide (TATP), while maintaining the sensitivities of secondary explosives. First, we investigated the detonation properties of TATP as donor charges in a detonation train. We developed a teleoperated pneumatic system to safely and reproducibly shape TATP charges at realistic densities, utilizing confined charges to approach infinite-diameter properties closely. The detonation pressure and shock adiabate of the detonation products were experimentally determined based on measured attenuated shock velocity in inert acceptors, and the experimental detonation products' isentrope was derived from cylinder expansion test results. These experimental findings were then compared to thermodynamic code calculations to assess the non-ideal behavior of TATP charges at 0.4 g/cm3. Subsequently, we conducted a similar characterization of proposed simulants, which replicate the detonation properties of TATP, particularly at a loose density of 0.5 g/cm3, as a basis for reproducing its detonation characteristics as a donor charge for safety margins. These simulants included Urea hydrogen peroxide (UHP) and diluted Nitro Methane. Their results were then compared to those predicted for TATP at 0.5 g/cm3 density. These candidates showed satisfactory agreement in the reflected Hugoniot of the detonation gases and the isentrope of the detonation products, suggesting them as promising simulants for TATP. This comprehensive study offers valuable insights into the potential use of these simulants as detonation surrogates for HMEs when employed as booster charges for tertiary explosives.