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Title: A molecular dynamics study of phase transition in strongly coupled pair-ion plasmas

Existence of phase transition in strongly coupled pair-ion plasmas with soft core is investigated. Extensive Molecular Dynamics (MD) simulations are performed in the canonical ensemble, for such plasmas, at different temperatures, to analyze phase stability. Our studies show interesting phase co-existence between liquid-like and vapor-like phases. The different phases are identified by calculating the ensemble averaged density. This and the corresponding critical properties are calculated directly from MD simulation. The critical temperature of vapor-liquid coexistence is obtained, and the corresponding critical value of density is also estimated for different sizes of the soft core. We have used a novel method that allows the location of phase coexistence through a constant density simulation in which the temperature is changed in a single time-step (quenching) in order to place the system in a thermodynamically and mechanically unstable state, resulting in spontaneous separation of two coexisting phases. The results obtained from this temperature quench MD method also show the coexistence of vapor-liquid phase in pair-ion plasmas. The critical exponents obtained directly from MD simulation are found to be in close agreement with the values predicted by a mean-field theory.
Authors:
;  [1] ;  [2]
  1. Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India)
  2. Department of Physics and Astrophysics, University of Delhi, Delhi (India)
Publication Date:
OSTI Identifier:
22490037
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CRITICAL TEMPERATURE; ION PAIRS; LIQUIDS; MEAN-FIELD THEORY; MOLECULAR DYNAMICS METHOD; PHASE STABILITY; PHASE TRANSFORMATIONS; PLASMA; PLASMA SIMULATION; STRONG-COUPLING MODEL; VAPORS