Characterizing the effect of strong magnetization in cylindrically imploded hot dense plasmas using dopant spectroscopy techniques and benchmarked simulations

The increased strength and volume of magnetic fields that can now be applied in experiments is pushing the frontiers of magnetized High-Energy-Density Physics (HEDP), as shown by the recent success of the Magnetized-Liner Inertial Fusion (MagLIF) scheme, as well as the subsequent study of magnetized Inertial Confinement Fusion (ICF) implosions to relax ignition constraints. The physics of magnetized transport in Magneto-Hydro-Dynamic (MHD) models warrants experimental validation. In addition, the interpretation of measurements from complex magnetized experiments requires novel and accurate modeling, such as detailed atomic and radiation transport physics for spectroscopy analysis.

We present the design, numerical simulations, and results of magnetized cylindrical implosions performed at the OMEGA facility. The cylindrical targets are filled with Ar-doped D₂ gas and are symmetrically imploded using a 40-beam, 14.5 kJ, 1.5 ns laser drive. The implosions are magnetized using the MIFEDS capability, delivering a seed B-field of 24 T along the axis of the cylindrical targets. X-ray framed imaging is used to follow the implosions' trajectory, and the compressed core conditions are obtained via Ar K-shell emission. We show that the Ar emission spectra are highly reproducible, and we observed distinct changes in the plasma conditions of the compressed core between the cases with and without the applied B-field. Advanced atomic codes and radiation transport calculations based on Gorgon spatial profiles provide an excellent match to the data. When magnetizing the implosions, the compressed B-field reaches ~10 kT and the subsequent anisotropy of the heat conduction along the radial direction enhanced the average temperature of the hot spot by ~70% (from ~1 keV to 1.7 keV).