RDX-Al and PETN-Al composites’ glow spectral kinetics at the explosion initiated with laser pulse

Abstract

Glow spectral kinetics of cyclotrimethylenetrinitramine (RDX) and pentaerythritol tetranitrate (PETN) based composites containing aluminum nanoparticles (average diameter 100 nm) caused by explosion stimulated by neodymium laser pulse (1064 nm, 14 ns) have been studied for the first time with nanosecond temporal resolution. The experiments have been performed in the conditions of gas-dynamic relaxation hindrance. The aluminum nanoparticles, as well as the surrounding shell of the RDX and PETN, are heated during the pulse. If the laser pulse energy density is higher than the critical one, the fluorescence, whose typical relaxation time is 50 ns, appears and spectral maximum is blue-shifted with elevating the energy density of the laser pulse. The fluorescence is related to NO2● formed in the radical dissociation of RDX and PETN molecules stimulated by rapid heating in the aluminum nanoparticles explosive environment. The following exothermal decomposition reaction leads to a sample explosion in the microsecond time range. The emission spectrum of the explosion products is a thermal one with temperatures 3500 K and 3400 K for RDX-Al and PETN-Al relatively, which has been estimated using spectral pyrometry approach.