ABLATION AND DRIVE OF TYPICAL MULTI-LAYER FLYERS BY HIGH POWER LASER BEAM

Laser driving technology is an important technology in high energy physics, shock wave physics and explosive initiation application. In this paper, velocities and impact stresses of four types of laser-driven flyers (Al, Al/Al2O3/Al, CuO/Al2O3/Al, (CuO/Al)/Al2O3/Al) prepared via magnetron sputtering were obtained by photonic Doppler velocimetry (PDV) and a self-made polyvinylidene fluoride (PVDF) stress sensor at ns-class pulse width.The results showed that velocities and integrity of flyers were influenced by their diameters. Compared with Al single-layer flyer, other multi-layer flyers with Al2O3 insulation layer owned lower velocity but better integrity and initiation properties.CuO/Al as the ablation layer enhanced the velocities and shock initiation properties of multi-layer flyers. Velocity of a flyer improved with the increasing laser energy while shock initiation property did not perform in the same way. These results provide some references for the design of multi-layer flyers applied to laserdriven initiation technology.

The Effect of Tube Materials on Metal Jet Initiating the Confined Composition B

The implementation and validation of a numerical model of the confined Composition B initiated by a metal jet has been studied by AUTODYN-2D. Two different tube thicknesses were used representing strong and weak confinement initiating system. In another contrast, various materials such as Nylon, St45 and Tungsten alloy were adopted to investigate the influence of tube yield stress on the confined explosives initiation behaviour. The results show that, in both cases, the confined explosive is always more likely to be initiated than bare explosive, and the explosive initiation probability increases with the tube thickness and yield stress. The run to detonation generally increases with the increasing lateral confining strength, but decreasing jet tip velocity.