Laser Initiation of PETN-Iron Nanoparticle Composites

The dependences of the probability of explosion initiation in pentaerythritol tetranitrate samples with different contents of iron nanoparticles on the fluence of the first-(lambda = 1064 nm) and second-harmonic (lambda = 532 nm) pulses of a neodymium laser are measured. The laser initiation threshold for PETN-iron nanoparticle composites nonmonotonically depends on the mass fraction of nanoparticles. The optimal values of the mass fraction of iron nanoparticles at which the sensitivity to laser irradiation is maximal (0.4 wt % for the first harmonic and 0.15 wt % for the second) are determined. It is demonstrated that the amplitude of the optoacoustic signal under non-explosion conditions reaches its maximum for composites with the optimal values of the mass fraction of nanoparticles.