AVS 52nd International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS+TF-ThA

Paper PS+TF-ThA3
Investigating the Plasma-Propellant Interaction through Experimental Modeling

Thursday, November 3, 2005, 2:40 pm, Room 302

Session: Emerging Plasma Applications
Presenter: R. Valliere, Auburn University
Authors: R. Valliere, Auburn University
R. Blumenthal, Auburn University
Correspondent: Click to Email
There has been a significant interest in the use of plasmas to ignite propellants in large bore artillery. A short, reproducible ignition delay and a reduced temperature dependence are the most important advantages of plasma ignition over conventional ignition. Using the experimental modeling method, pioneered by Winters and Coburn,@footnote 1@ the erosion rates of sprayed-on films of RDX and HMX have been investigated in inert and reactive plasmas, as a function of sample bias in order to isolate the ion and electron bombardment and chemical effects on the erosion rate. No significant erosion rate was observed in argon plasmas with zero or positive bias, indicating that erosion by electron bombardment alone is not significant. Under ion bombardment conditions, large negative bias, only a slow erosion rate (presumably due to sputtering) was observed. Erosion in hydrogen plasmas is quite different. The minimum erosion rate, observed at positive and zero sample biases, was ~100x the maximum rate observed in negative-biased argon plasmas. Under negative bias the erosion rate increased as a much as 20-fold, depending on a combination of ion current and sample bias. All observed erosion rates obey pseudo-first order kinetics. The fact that the erosion rates in the hydrogen plasmas are all much greater than the rates of the argon plasmas, even at large negative bias, indicates a strong chemical component to the erosion process. The bias and current dependence of the erosion rate in hydrogen plasmas indicate a synergistic effect between ions and reactive neutrals. The kinetics of erosion for the individual species and the synergistic effects between them will be presented. @FootnoteText@ @footnote 1@ H.F. Winters, and J.W. Coburn, JVSTB @bold 3(5)@, 1376 (1985).