Ion Temperature Evolution in an Ultracold Neutral Plasma
arXiv:1501.06944 · doi:10.1063/1.4915135
Abstract
We study the long-time evolution of the ion temperature in an expanding ultracold neutral plasma using spatially resolved, laser-induced-fluorescence spectroscopy. Adiabatic cooling reduces the ion temperature by an order of magnitude during the plasma expansion, to temperatures as low as 0.2 K. Cooling is limited by heat exchange between ions and the much hotter electrons. We also present evidence for an additional heating mechanism and discuss possible sources. Data are described by a model of the plasma evolution, including the effects of ion-electron heat exchange. We show that for appropriate initial conditions, the degree of Coulomb coupling of ions in the plasma increases during expansion.
References in corpus (6)
- Molecular Dynamics Simulations of Temperature Equilibration in Dense Hydrogen
- Using Three-Body Recombination to Extract Electron Temperatures of Ultracold Plasmas
- Experimental Realization of an Exact Solution to the Vlasov Equations for an Expanding Plasma
- Electron Temperature Evolution in Expanding Ultracold Neutral Plasmas
- Velocity Relaxation in a Strongly Coupled Plasma
- Recombination fluorescence in ultracold neutral plasmas