Laser Ablation of Energetic Materials

Abstract

The initiation of explosives by laser is a new initiation method. Compared with traditional initiation methods, laser initiation has the characteristics of high reliability and high safety. It can be used as one of the alternative technologies for future initiation device. A microscopic understanding of the complex physical and chemical processes involved in the reaction process is essential for laser initiation. Shock initiation technology of laser-driven flyer was studied. Several typical laser-driven flyer targets researches were introduced. Some significant characteristics including velocity and impact stress of flyers were tested via photonic Doppler velocimetry and polyvinylidene fluoride pressure sensor, respectively. Some types of flyers including Al and Cu single-layer flyers and CuO/Cu, CuO/Al, and CuO/Al/ Cu multilayer flyers with relatively high velocities were used to initiate PETN explosive. In order to give a better understanding of the mechanism of laser interaction with typical energetic materials (RDX, HMX, TNT, and HNS), a time of flight mass spectrometer (TOFMS) was used to detect the positive ions and the negative ions were produced in the laser-induced dissociation processes. The influences of laser wavelength, the laser fluence, and the delay time of the decomposition process have been studied as well. The results may throw some light on the laser interaction mechanism of energetic materials.

Fabrication and Optimization Design of Multilayer Flyer Plates for Laser-Driven Loading

“…e energy was prestored in the ablation layer of the MFPs through the aluminothermic film. When the laser excited the MFPs, the stored energy will be used as one of the sources of plasma expansion and work, thereby increasing the total energy of MFPs [19,[28][29][30]. In addition, the introduction of the aluminothermic film reduced the reflectivity of the 1064 nm laser, which was conducive to the ablation layer film to absorb more laser energy, so as to improve the utilization efficiency of laser energy.…”