Phase-Space Dynamics of Sculpted Ultracold Neutral Plasmas.

Through a series of molecular dynamics simulations we have explored the non-equilibrium dynamics of heterogeneous non-ideal plasmas formed with spatially modulated ionizing radiation. We have developed a computational model for such sculpted ultracold neutral (SUN) plasmas formed by ionizing an ultracold neutral gas. We model ion dynamics through a screened Coulomb interaction in which the screening length varies according to the dynamics. Ion-electron and ion-neutral collisions are modeled though Langevin forces, allowing us to examine the role of heating or cooling due to background species. We constructed a hydrodynamic model for SUN plasmas and compute its field quantities (density, flow velocity and temperature) in the molecular dynamics simulations, included examining the accuracy of a local-equilibrium closure. We have examined these quantities and others, such as the spatial Coulomb coupling parameter, in three geometries, including a double slab, a solid rod and a hollow rod. Our results suggest that a wealth of plasma physics can be explored with SUN plasmas; however, we also discuss where further improvements to our computational tools are warranted for future studies.