Ultracold neutral plasmas

Abstract

Ultracold neutral plasmas, formed by photoionizing laser-cooled atoms near the ionization threshold, have electron temperatures in the 1-1000 kelvin range and ion temperatures from tens of millikelvin to a few kelvin. They represent a new frontier in the study of neutral plasmas, which traditionally deals with much hotter systems, but they also blur the boundaries of plasma, atomic, condensed matter, and low temperature physics. Modelling these plasmas challenges computational techniques and theories of non-equilibrium systems, so the field has attracted great interest from the theoretical and computational physics communities. By varying laser intensities and wavelengths it is possible to accurately set the initial plasma density and energy, and charged-particle-detection and optical diagnostics allow precise measurements for comparison with theoretical predictions.Recent experiments using optical probes demonstrated that ions in the plasma equilibrate in a strongly coupled fluid phase. Strongly coupled plasmas, in which the electrical interaction energy between charged particles exceeds the average kinetic energy, reverse the traditional energy hierarchy underlying basic plasma concepts such as Debye screening and hydrodynamics. Equilibration in this regime is of particular interest because it involves the establishment of spatial correlations between particles, and it connects to the physics of the interiors of gas-giant planets and inertial confinement fusion devices.

Polarized Thermal Conductivity of Two-Dimensional Dusty Plasmas

“…Thermodynamic properties are defined by the equilibrium conditions of the system which consist of temperature, heat capacity, entropy, pressure, internal energy, enthalpy, and density, whereas the transport properties comprise thermal conductivity, diffusion viscosity, and waves with their instabilities. For further explanation of the process in detail for these systems, data that is applicable to thermodynamics, transport, optics, transmission, light, and other features are required for non-ideal plasma [5][6][7][8][9]. In this regard, various opinions regarding computer research methods including theoretical and numerical performance have greatly improved for non-ideal Plasma [10].…”

High-frequency response of classical strongly coupled plasmas

“…The dynamic structure factor (DSF) plays a central role in our understanding of strongly coupled plasmas because it provides a clean description of the equilibrium dynamics of correlations that occur in white dwarfs [1], giant planets [2], dusty plasmas [3], ultracold plasmas [4] and dense plasmas [5]. In particular, the DSF contains dynamical information needed to properly describe and model collective modes and transport [6][7][8][9], while also providing information on stopping power [10,11], neutron scattering [12], X-ray Thomson Scattering (XRTS) [13], and microfields [14].…”

Stopping Power of Ions in a Magnetized Plasma: Binary Collision Formulatio

“…The energy loss of ion beams and the related processes in magnetized plasmas are important in many areas of physics such as transport, heating, magnetic confinement of thermonuclear plasmas, and astrophysics. The range of the related topics includes ultracold plasmas [1,2], the cooling of heavy ion beams by electrons [3][4][5][6][7][8][9][10][11][12], as well as many very dense systems involved in magnetized target fusions [11], or heavy ion inertial confinement fusion (ICF).…”