Study of the core-corona structure formed during the explosion of an aluminum wire in vacuum

The time evolution of the matter parameters and current distribution in the discharge channel formed during a nanosecond explosion of a 25-μm-diameter 12-mm-long aluminum wire was studied in a series of experiments with the following parameters: the discharge voltage was U0 = 20 kV, the current amplitude was Imax ∼ 8 kA, and the current rise rate was dI/dt ∼ 40 A/ns. Optical shadow and schlieren images of the discharge channel were obtained using the second harmonic of a YAG: Nd+3 laser, and UV images of the discharge channel self-radiation were recorded using a four-frame camera with a microchannel plate. The process of aluminum wire explosion was simulated numerically (including simulations performed from the "cold start"). The numerical results were compared with the experimental data.