Numerical simulation of electric explosions of metal wires

摘要

Summary form only given. The successful application of z-pinches as high-power X-ray sources has aroused interest in the study of electric explosion of wires, particularly in vacuum. A large body of experimental data suggests that the explosion of a wire in vacuum is accompanied by the formation of strata and low-density plasma corona surrounding a dense core. It seems likely that early in the explosion this low-density corona consists of a gaseous matter, which is initially sorbed by the wire surface, while later in the process it is formed by metal vapors. We have already simulated the explosion of wires in a liquid dielectric with the use of a 1D magnetohydrodynamic (MHD) code based on the Lagrangian approach, and the results obtained have shown a good agreement with experimental data. However, with this code it is fundamentally difficult to simulate the explosion of wires in vacuum, since the MHD equations are approximated on a grid associated with the mass coordinates of the fluid, thus making impossible a correct simulation of the processes involving very large density differences. In case of the electric explosions of wires in vacuum, the density of a liquid metal is several orders of magnitude higher than that of vapors surrounding it. Therefore, it would appear more reasonable to simulate the process by the particle-in-cell method (the PIC method), where the particles moving on a fixed computational grid (Eulerian grid) are taken to be Lagrangian components.