Explosive decomposition of slightly compacted powders of lead azide over a wide range of laser pulse length

Initiation of slightly compacted powders of lead azide of density not greater than 1.2 g/cm$^3$ by laser radiation with a wavelength of 1.06 $\mu$m was studied experimentally over a wide range of pulse lengths (10$^{-5}$–10$^{-3}$ sec). It is shown that the ignition threshold of the slightly compacted samples does not change as the laser pulse length is increased. It is found that the explosion products contain molten lead particles whose sizes are an order of magnitude larger than the sizes of similar particles from explosion of samples of density 4.0 g/cm$^3$.