High-speed Measurement of Decomposition and Inactivation Mechanisms of Chemical Warfare Agent Simulants at High Heating Rates
Abstract
Defeat of chemical warfare agents (CWAs) requires knowledge of their decomposition during events of high heating rate which are comparable to detonation and post blast environments. Moreover, in order to develop better simulations of the defeat of CWAs, experimental data on the decomposition of CWAs under high heating rates is needed. This necessitates measurement of CWA decomposition species, temperature, and concentration at several orders of magnitude faster speeds than current measurements. This work aims to combine recently developed near detonation speed electrically heating filament (t-jump) and CO2 laser-based thermal heating experiments with sub-microsecond and ultrafast laser diagnostics in order to explore CWA decomposition and inactivation mechanisms at high speeds. The proposed work is comprised of three basic thrusts: (1) exploration of CWA decomposition/inactivation at high rates (~1000 to 107 °C/s) using t-jump or laser heating coupled with sub-microsecond temporal resolution, tunable, quantum cascade laser infrared absorption measurements to monitor the decomposition/inactivation of CWA simulants, (2) quantitative determination of the time evolution of temperature, species, and CWA vapor concentration at high heating rate using nanosecond, time-resolved ‘single shot’ Raman/Rayleigh scattering and vapor fluorescence, respectively, and (3) spatial measurement of temperature/species during thermal decomposition/inactivation at high heating rate using coherent anti-Stokes Raman scattering (CARS, sub-nanosecond). Experiments will focus on determining (a) fundamental decomposition mechanisms of CWA simulants and (b) effectiveness of the use of defeat agents in neutralizing CWA threats. The proposed approach will resolve CWA decomposition/inactivation mechanisms over an unprecedented range of thermal heating rates and extend heating rate and timescale measurements of species, temperature, and concentration by orders of magnitude while also providing spatial resolution at these rates in a safe, low-cost experimental configuration in order to extend the understanding of CWA decomposition and inactivation from deflagration to near detonation thermal regimes. The overall impact of this work will be a rich experimental understanding of the decomposition of chemical warfare agent simulants, which will enable calibration and accuracy improvement of computer simulations of such events. This will lead to development of more effective CWA neutralization capabilities, and a reduction in both risk and timeline for development of neutralization systems to address emerging CWA threats.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 26, 2016
- Source ID
- HDTRA11610011
Entities
People
- Travis R. Sippel
Organizations
- Defense Threat Reduction Agency
- Iowa State University