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Title: Ion temperature evolution in an ultracold neutral plasma

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‚ÄČK. 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.
Authors:
; ; ;  [1]
  1. Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)
Publication Date:
OSTI Identifier:
22408261
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COLD PLASMA; COOLING; COULOMB FIELD; ELECTRON-ION COLLISIONS; FLUORESCENCE SPECTROSCOPY; HEAT; HEATING; ION TEMPERATURE; LASERS; PLASMA EXPANSION