If a HMX-based explosive is subjected to an insult then there is a potential for the insulted β-HMX to undergo a phase change to the more sensitive δ 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 δ-HMX has been formed, as this would subsequently affect the intrinsic safety properties of the formulation. δ-HMX, unlike the more stable β 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 δ-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 δ 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.

Date Published: 13 September 2007
PDF: 10 pages
Proc. SPIE 6662, Optical Technologies for Arming, Safing, Fuzing, and Firing III, 666209 (13 September 2007); doi: 10.1117/12.734178

Published in SPIE Proceedings Vol. 6662:
Optical Technologies for Arming, Safing, Fuzing, and Firing III
William J. Thomes; Fred M. Dickey, Editor(s)