Applying dielectric coatings and enhanced input parameters to generate a stable, high performing MagLIF configuration*

.The Magnetized Liner Inertial Fusion (MagLIF) platform [1,2] requires three critical inputs to achieve robust fusion conditions: an applied axial magnetic field that provides thermal insulation, laser preheat that reduces convergence requirements, and a z-pinch implosion of a solid metal liner, that provides the PdV work and confinement of the fuel. In recent years, improving these capabilities has been a focus of the MagLIF efforts [2,3,4] on the Z machine, enabling enhanced performance and scaling studies. Although fusion yields achieved in experiments increased, they did not achieve the possibilities predicted by ideal 2D simulations with these improved capabilities.

 

State-of-the-art 3D HYDRA MHD modeling of experiments performed on Z show the magneto-Rayleigh-Taylor instability significantly degrades implosion quality compared to 2D simulations and disrupts expected scaling to higher currents. To improve stability, we have introduced dielectric coatings aimed at reducing instability seeds [5]. To simulate this dielectric, we have developed a simple model to transition the coating from insulator to conductor guided by comparisons to experimental radiographs of imploding coated liners. Guided by insights from 3D modeling, recently two aspect ratio 9 (AR=r_out/\delta_liner) dielectric coated integrated experiments were performed combining improved preheat (~ 2.3 kJ), improved current coupling (18 MA), and increased applied field (15 T), producing record D-D neutron yields roughly a factor of two greater than the previous record. Initial analysis of the morphology also shows improved stability compared to uncoated liners driven with 20 MA. Beyond this successful demonstration, we believe the platform can be further improved with higher quality targets, optimization of the dimensions and reduced convergence ratio.