A study of the Rayleigh-Taylor Instability during deceleration in inertial confinement fusion relevant conditions

The Rayleigh-Taylor instability (RTI) is one of the primary hydrodynamic instabilities that acts as a disputer to achieving high yield inertial confinement fusion (ICF). The potential for RTI to grow on the interior surface of ICF capsules, caused by deceleration during the implosion, further emphasises the need to better understand the seed mechanisms for RTI and possible mitigation methods for damping the instability growth. Reducing the growth of RTI during deceleration could preserve the spherical symmetry of ICF implosions and reduce the amount of mix between the solid capsule liner and fuel hot-spot. Additionally, it has been shown that magnetic fields do damp RTI growth, and the presence of a magnetic field lowers the threshold for achieving fusion and increases the yield. Understanding the seed mechanisms of the RTI, especially on the interior surface of ICF capsules, further allows for better understanding of the morphology of the RTI growth dur- ing deceleration. Classically RTI has been studied using single or multi-mode sinusoidal perturbations, which result in bubble and spike morphology. However in addition to si- nusoidal perturbations, single-feature perturbation, such as voids or divots, can seed RTI. This form of RTI is considered the thin-layer RTI, where the perturbation's wavelength is longer than the dense layer's thickness. This specific RTI evolution results in a morphology consisting of a single central spike and arms that extend horizontally away from the spike and eventually fall back towards the interface. Thin-layer RTI is important to explore dur- ing deceleration due to the presence of the fill-tubes in ICF capsules causing holes in the shell. Creating experimental platforms for current laser configurations on Omega and the Na- tional Ignition Facility (NIF) is necessary to study deceleration-stage RTI experimentally and validate computational modeling. A comprehensive exploration of potential experimen- tal designs on Omega, Omega-EP, and NIF are explored to identify a platform with which deceleration-stage RTI can be studied with and without the presence of an externally applied magnetic field. Additionally, the design of a novel experimental platform for Omega-EP to study thin-layer RTI during deceleration with and without an externally applied magnetic field is presented, along with data collected during the first experiments performed utilizing the platform. Lastly, a first of it's kind RTI platform for NIF is fielded and the results are presented, including an exploration of the possible impacts high-intensity-laser generated hot-electrons can have on experimental targets. The results of these experimental platforms are used to benchmark computational models, and demonstrate the potential for magnetized RTI to be studied comprehensively in future experiments.