A computational and experimental exploration of the effects of strong magnetic fields on the deceleration-stage Rayleigh-Taylor instability related to high energy density systems*

The Rayleigh-Taylor instability (RTI) has been identified as one of the largest inhibitors of successful high-gain inertial confinement fusion (ICF) experiments. It has been shown that the presence of a magnetic field both lowers the ignition threshold, increases fusion yield, and damps RTI growth. Thus, the development of an experimental platform from which deceleration-stage RTI can be studied with and without a magnetic field is crucial to understanding the disruptive nature and potential mitigation of RTI in ICF. A series of computational design studies identifies a viable design to study deceleration-stage RTI at the National Ignition Facility (NIF). The resulting experimental data from the novel design demonstrates that key physics is missing in the design model. A subsequent Omega-EP experimental design, intended to mirror the NIF platform, demonstrates the presence of a significant high-intensity-laser-generated hot-electron population. A computational study of the impact of hot-electron induced preheat on the NIF and Omega-EP targets illustrates the possibility for a preheat regime to render RTI growth unresolvable experimentally, as is seen in the NIF data. Additional Omega-EP experimental results illustrate the need for 3D rather than 2D computational models to be used in the design process of high-fidelity targets to study deceleration-stage RTI with and without a magnetic field. LA-UR-XX-XXXX