Investigation of coated surface ablation in the thick regime on pulsed-power drivers*

Recent studies have proposed developing warm dense matter (WDM) using pulsed-power drivers. Pulsed-power drivers use magnetic fields to compress matter into the Mbar regime, relaxing the confinement time necessary to reach the mesoscale. The purpose of this campaign is to study the properties of bulk materials in WDM samples on longer time scales. Surface ablation from a thick conductor such as a rod offers new, unpredictable current paths, ultimately leading to very disparate, mixed states, that hinder the measurements of the properties of WDM samples. The addition of coating prevents the formation of ablated plasma around the conductor and has proven to reduce expansion. The damping layer limits the current to flow very close to the conductor surface, reducing parasitic current flows outside of the conductor, allowing full control of the magnetic field topology by the shape of the conductor alone. Reducing expansion and preventing surface ablation allows for greater magnetic pressure during the compress phase. We propose investigating the surface ablation in the visible regime to determine the temperature and resistivity of these samples. An analysis of coated surface ablation on Al rods in the visible spectrum is presented here.