Influenc Of Dielectric Coating And Soldering On Electrical Explosion Of Tungsten Wires

The study on the fast electrical explosion of a metal wire has been the focus of interest of many recent studies due to its wide applications in many fields. This paper presents the experimental results of the tungsten (W) wire explosions. Three kinds of W wires (bare, $2 \mu \mathrm {m}$ PI coating, $3.5 \mu \mathrm {m}$ PI coating) are exploded under two electrical contact conditions (glue, soldering) with the same charging voltage. A laser probe is applied to construct the shadowgraphy, schlieren and interferometry diagnostics. The morphology and density of the exploding product can be derived from the shadowgraph and interferogram, while the distribution of the gas and plasma can be observed from the schlieren images. Experimental results show that the use of the dielectric coating can effectively increase the energy deposition and the expansion velocity. However, in some shots, the energy deposition along the wire is non-uniform and the W wire is divided into two distinct parts. When the W wire is soldered to the electrodes, the improved electrical contact does not obviously lead to more energy deposition. However, the uniformity of the energy deposition along the wire is improved remarkably. The radial electric field of each case is calculated by electrostatic simulation with COMSOL, and the influence of soldering on the electric field is discussed.