Experimental measurement of non-Markovian dynamics and self-diffusion in a strongly coupled plasma

Abstract

We present a study of the collisional relaxation of ion velocities in a strongly coupled, ultracold neutral plasma on short timescales compared to the inverse collision rate. Non-exponential decay towards equilibrium for the average velocity of a tagged population of ions heralds non-Markovian dynamics and a breakdown of assumptions underlying standard kinetic theory. We prove the equivalence of the average-velocity curve to the velocity autocorrelation function, a fundamental statistical quantity that provides access to equilibrium transport coefficients and aspects of individual particle trajectories in a regime where experimental measurements have been lacking. From our data, we calculate the ion self-diffusion constant. This demonstrates the utility of ultracold neutral plasmas for isolating the effects of strong coupling on collisional processes, which is of interest for dense laboratory and astrophysical plasmas.

arXiv comment5 figures, 8 pages

References in corpus (11)

• Creation of an Ultracold Neutral Plasma
• A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes
• Magnetic trapping of metastable ${}^3{P}_2$ atomic strontium
• Ion Acoustic Waves in Ultracold Neutral Plasmas
• Experimental Realization of an Exact Solution to the Vlasov Equations for an Expanding Plasma
• Self-Diffusion in 2D Dusty Plasma Liquids: Numerical Simulation Results
• Velocity Relaxation in a Strongly Coupled Plasma
• Superdiffusion in quasi-two-dimensional Yukawa liquids
• Ion Temperature Evolution in an Ultracold Neutral Plasma
• Demonstrating Universal Scaling in Quench Dynamics of a Yukawa One-Component Plasma
• Creating Non-Maxwellian Velocity Distributions in Ultracold Plasmas

Cited by in corpus (17)

• Mean Force Kinetic Theory: a Convergent Kinetic Theory for Weakly and Strongly Coupled Plasmas
• Testing thermal conductivity models with equilibrium molecular dynamics simulations of the one component plasma
• Effective Potential Theory for Diffusion in Binary Ionic Mixtures
• Simple dispersion relations for Coulomb and Yukawa fluids
• Thermodynamic State Variables in Quasi-Equilibrium Ultracold Neutral Plasma
• Self-diffusion in single-component Yukawa fluids
• Dissipative dynamics of atomic and molecular Rydberg gases: Avalanche to ultracold plasma states of strong coupling
• Ion friction at small values of the Coulomb logarithm
• Reduction of electron heating by magnetizing ultracold neutral plasma
• Fractional Laplacian Spectral Approach to Turbulence in a Dusty Plasma Monolayer
• Reduced Ionic Diffusion by the Dynamic Electron-Ion Collisions in Warm Dense Hydrogen
• Expansion of Ultracold Neutral Plasmas with Exponentially Decaying Density Distributions
• FPGA based demodulation of laser induced fluorescence in plasmas
• Velocity space degrees of freedom of plasma fluctuations
• A technique for plasma velocity-space cross-correlation
• Intrinsic bulk viscosity of the one-component plasma
• Many-body collision contributions to electron momentum damping rates in a plasma influenced by electron strong coupling