Burning of a powder in the presence of luminous radiation

Abstract

The above qualitative picture of the influence of a luminous flux on the burning of explosives should also remain valid when the kinetic laws are different or when the leading combustion zone is not the zone of chemical reactions in the condensed phase, but some other zone. This follows from the fact that in all these cases, if it is thermal, the effect of luminous radiation on the burning process must be described by the same term in the heat conduction equation. Hence it follows, in particular, that it is possible to use luminous radiation for studying the burning mechanism of explosives. If, for example, one of the combustion zones is transparent in a certain wavelength interval (gas phase), while in the same interval another (condensed phase) experiences a marked change in transmissivity, then by irradiating the explosive with sufficiently powerful light fluxes at different wavelengths we can establish which is the leading zone. The presence of a dependence of burning rate on wavelength will indicate that this is a chemical reaction zone with strongly varying transmissivity, and the absence of such a dependence that the leading zone is a zone of weakly varying transmissivity.