Plasma parameters in burn rates processes of a solid propellant for electrothermal-chemical launch devices

Summary form only given, as follows. A plasma source for an electrothermal-chemical (ETC) device produces a high-density, low-temperature plasma, which has a near-blackbody spectrum. Burn rates of solid propellants may be limited by absorption of a large fraction of the source fluence in the developed vapor cloud. The electrothermal-chemical experimental facility PIPE at NC State University is used to characterize the burn rates of single grain monolithic JA2 propellant. It has been shown that burn rates are much higher than that of conventional ignition, especially when the plasma is injected normal to the grain. The plasma core temperature at the source exit is higher than that of the plasma boundary layer, and is evaluated from the measured discharge parameters, then compared to predictions of the 1-D, time dependent code SODIN and analytical scaling laws. Boundary layer temperature and density are evaluated from optical emission spectroscopy. It appears that plasma kinetic pressure has a stronger effect on the burn rate than the plasma radiative heat flux. Results on the effect of source parameters on measured burn rates will be presented.