Explosive decomposition kinetics of tetranitropentaerythrite aluminum pellets

Abstract

The explosive decomposition kinetics of tetranitropentaerythrite aluminum compressed pellets is studied with a high time resolution. Explosive decomposition is initiated by a pulsed 1064-nm laser with a pulse FWHM of 12 ns. Emphasis is on the prethreshold glow mode, which sets in at a pulse energy density below 1 J/cm2. The ascending part of the glow intensity curve is described by a Gaussian function with effective constant k = (1.2 + 0.2) × 108 s−1. The characteristic decay time is about 40 ns. The total glow duration does not exceed 100 ns. Explosive decomposition becomes noticeable immediately during the pulse: the induction period is absent. The initial portion of the glow intensity curve is described by a Gaussian function with effective constant k = (1.4 + 0.1) × 108 s−1. The explosive glow kinetics is biextremal. The first peak is nearly coincident with the maximum of the laser action, and the extension of the second peak is 600 ns. Experimental data are treated in terms of the prethreshold model of thermal explosion.