Reduction of ablated surface expansion in pulsed-power-driven experiments using an aerosol dielectric coating

The quality of warm dense matter samples created by magnetic compression can be largely affected by material ablation. When the ablated material carries currents, local instabilities can grow, which can lead to nonuniformities in the final magnetic pressure. Extending the previous work by Peterson et al. [Phys. Rev. Lett. 112, 135002 (2014)], Awe et al. [Phys. Rev. Lett. 116, 065001 (2016)], and Hutchison et al. [Phys. Rev. E 97, 053208 (2018)], the experiments reported here demonstrate that the expansion of the ablated material can be significantly reduced by using a simple aerosol spray technique. Coating the current-carrying surfaces with a 30–60-μm layer of polyurethane reduced the expansion of the ablated material by a factor of 2 and eliminated material ejections from sharp corners. This technique, tested at the Michigan Accelerator for Inductive Z-Pinch Experiments pulsed power facility at the University of Michigan with currents up to 400 kA, could allow the production of homogeneous warm dense matter samples on pulsed-power drivers. Because of the simplicity of this method, this work brings forth an important contribution to pulsed-power-driven experiments designed to study nuclear fusion, material properties, and radiation science.