Description
Measuring the current density in the low density corona of exploding wires remains experimentally challenging. Therefore, this region is investigated using resistive MHD simulations during the expansion phase.
The numerical results are validated using x-pinch driven proton radiographs obtained using the MAIZE and XP generators. The MAIZE facility delivered a peak current of 400 kA with a rise time of approximately 150 ns to the x-pinch. The XP generator was employed to produce a 500 kA current peaking at 70 ns. One quarter of the total current is estimated to couple to the exploding wire. Both facilities utilised 25 µm aluminium wire.
Furthermore, the analysis compares how the short (70 ns) and long (150 ns) driver timescales alter the overall plasma evolution. Further attention is given to instability development and the role of skin effect, anomalous resistivity and magnetic diffusion in shaping the coronal current. This computational approach yields insight into plasma regions inaccessible to standard diagnostics.
The simulations in this work are performed using the multi-physics FLASH code, developed by the Flash Center for Computational Science, currently hosted at the University of Rochester.
This work was supported by the Grant Agency of the Czech Republic (Project No. GM23-05027M). The U. of Michigan team was supported by DOE Cooperative Agreement DE-NA0004148.