Measuring the brightness temperature of a detonation front in a porous explosive

The detonation temperature of pressed PETN grains with a relative volumetric concentration of air pores of 0.0047–0.147 was measured using an optical fiber pyrometer at wavelengths of 678 and 487 nm. The nonequilibrium nature of the radiation of the detonation front was shown to be due to the presence of two radiation sources with different temperatures. One source was the explosion products and the other was the strongly compressed air pores, in which air was heated to a temperature above 10$^4$ K.