Ultracold neutral plasmas as high-energy-density plasma simulators*

After presenting an overview of ultracold neutral plasma (UNP) physics, I will explore situations in which ultracold neutral plasmas can be used to simulate the high-energy-density plasma (HEDP) environment. This will include the micro-physics of ion friction, energy and velocity relaxation, electron-ion thermalization, and the separation of hydrodynamic flow and thermal motion. Even though UNP and HEDP science occurs over vastly different scales in temperature and density, thermodynamic and kinetic properties can be scaled using the dimensionless parameters $\Gamma$, the Coulomb strong-coupling parameter, and $\kappa$, the inverse scaled screening length. In UNPs, the value of $\Gamma$ ranges from 0.1 to about 10. The value of $\kappa$ ranges from 0 to 0.6. The low temperature and density make it possible to measure kinetic effects with high precision. Computer modeling and simulations are similarly straightforward, enabling the extraction of diffusion coefficients, Coulomb logarithms, and collision rates. Future areas of HEDP/UNP overlap will be discussed.