Energetic Al/Ni Superlattice as a Micro-Plasma Generator with Superb Performances

In this study, energetic Al/Ni superlattice was deposited by magnetron sputtering. A micro-plasma generator was fabricated using the energetic Al/Ni superlattice. The cross-sectional micro-structure of the energetic Al/Ni superlattice was scanned by transmission electron microscopy. Results show that the superlattice is composed of Al layer and Ni layers, and its periodic structure is clearly visible. Moreover, the bilayer thickness is about 25 nm, which consists of about 15 nm Al layer and 10 nm Ni layer. The micro initiator was stimulated using a 0.22 μF capacitor charged at 2900-4100 V. The electrical behaviors were investigated by testing the current-voltage waveform, and the plasma generation was explored by ultra-high-speed camera and photodiode. The integrated micro generator exhibited remarkable electrical exploding phenomenon, leading to plasma generations at a small timescale. The plasma outputs reflected by flyer velocities were superior to that with a much thicker bilayer of 500 nm Al/Ni multilayer. The higher flyer velocity combined with Gurney energy model confirmed the chemical reaction of the Al/Ni superlattice structure contributed to plasma production in comparison with the Al/Ni multilayers. Overall, the energetic Al/Ni superlattice was expected to pave a promising avenue to improve the initiator efficiency at a lower energy investment.