Viscosity Control in High Energy Density Regimes Relevant to Inertial Confinement Fusion

Simulations of inertial-confinement-fusion (ICF) implosions play an important role in the design and analysis of different ICF targets. Hydrodynamic instabilities that occur during the implosion result in a non-uniform fuel compression and can mix colder ablator material into the fuel, both of which reduce the yield. However, viscosity is known to act as a saturation mechanism for hydrodynamic instabilities. This work utilizes simulations to investigate regimes where plasma viscosity is most influential for the behavior of ICF implosions. We analyzed this by characterizing different parameters such as coupling strength, Debye length, viscosity, and shock propagation while changing the materials and laser pulse shape in radiation-hydrodynamics simulations of these implosions. We identify parameter regimes where viscosity is expected to play a role in stabilizing hydrodynamic instabilities.