Laser initiation of a mixture of PETN with NiC nanoparticles at elevated temperatures

The temperature dependence of the probability of the explosion of pentaerythritol tetranitrate (PETN) with an admixture of NiC particles (0.3 wt %) initiated by laser pulses (1064 nm, 20 ns) was studied over the temperature range 295–450 K. At 295–350 K, a weak temperature dependence was observed. The determining contribution to explosion initiation was made by the absorption of laser radiation by nanoparticles. The threshold of explosive decomposition at 295 K decreased by ∼40 times compared with samples free of NiC nanoparticles. Over the temperature range 400–450 K, the threshold of the explosive decomposition of samples containing NiC nanoparticles decreased with the activation energy ∼0.4 eV. A decrease in the threshold of explosive decomposition with a ∼0.4 eV activation energy over the temperature range 340–440 K was also observed for laser action on PETN samples not containing NiC. A hypothesis was suggested according to which the absorption of a light quantum caused the transfer of an electron from the valence band of the crystal to a level in the forbidden band with subsequent thermal positive ion dissociation to the carbocation and NO₃ radical.