Embedded Infrared Fiber Optic Absorption Studies of Nitramine Propellant StrandBurning

摘要

We report on continued work to develop and demonstrate the use of infrared fiberoptics to probe the decomposition processes in burning gun propellant strands. Our experiments involve measuring the absorption across an open gap between two embedded fibers as it fills with gaseous decomposition products. Several improvements have been made to the experimental technique. In the most significant, detection techniques for the nitrogen oxide species NO2 and NO have been added to the N2O detection system developed in earlier work. O2 detection was accomplished by differential absorption of red and green HeNe lasers, while NO detection used a tunable infrared diode laser. We have observed N2O, NO2 and NO evolving into the observation volume during the burning of an RDX-based composite propellant. Observations to date indicate that NO appears at similar times as N2O, that is, while the observation region is relatively cool and far from the burning surface, while NO2 can significantly precede both NO and N2O. These data will provide additional information on the physical and chemical processes in the condensed phases of this composite propellant. (MM).