Development of a portable non-contact optical diagnostic system for the detection of δ-HMX

摘要

If a HMX-based explosive is subjected to an insult then there is a potential for the insulted P-HMX to undergo a phase change to the more sensitive 8 form. AWE has an ongoing programme to develop a science-based model of the response of HMX-based explosives to potential insults. As part of this programme there is a need to identify whether 8-HMX has been formed, as this would subsequently affect the intrinsic safety properties of the formulation. 8-HMX, unlike the more stable (3 form, exhibits unusual optical properties for an explosive, as it acts as a frequency-doubling material. When illuminated by a high-energy laser pulse areas of the explosive charge that contain 8-HMX emit frequency doubled light. This non-linear optical phenomenon allows for a non-invasive diagnostic to be developed to study creation of the more sensitive 8 phase within HMX based formulations. AWE has developed a portable diagnostic system based on this concept to investigate the behaviour of HMX-based explosives after low-speed impacts. The results of the commissioning trials are presented; using both an inert simulant, KDP, to align and prove the system and HMX samples from low-speed impact experiments. The results of these experiments are compared to initial calculations using the Hydrocode EDEN.