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Title: Linear-mixing model for shock-compressed liquid deuterium

Abstract

A model has been developed for the equation of state of deuterium that builds in the correct limiting behavior for the molecular fluid at low pressure and extends smoothly through dissociation to the very high-density monatomic-metallic fluid. The key assumption is that the Helmholtz free energy of the dissociating mixture is a function that can be approximated by the composition average of the free energy of the pure molecular and metallic hydrogen equations of state. The composition is determined by minimizing the free energy. In comparison to earlier studies this model leads to an enhancement of molecular dissociation and a lowering of shock temperatures and pressures. Calculations for shock-compressed liquid deuterium are in agreement with experiments to a pressure of 2.1 Mbar. At about 1 Mbar and 20thinsp000 K liquid deuterium is 90{percent} dissociated and is a nearly degenerate metal. The model predicts that molecular dissociation will lead to negative values of ({partial_derivative}P/{partial_derivative}T){sub V} in the range 4000 to 10thinsp000 K and volumes below 7 cc/mol. This feature suggests the formation of covalently bonded species in the partially dissociated mixture. {copyright} {ital 1998} {ital The American Physical Society}

Authors:
 [1]
  1. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Publication Date:
OSTI Identifier:
638786
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter
Additional Journal Information:
Journal Volume: 58; Journal Issue: 2; Other Information: PBD: Jul 1998
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DEUTERIUM; LIQUIDS; SHOCK WAVES; EQUATIONS OF STATE; FREE ENERGY; PRESSURE DEPENDENCE; DISSOCIATION; TEMPERATURE DEPENDENCE; MIXING

Citation Formats

Ross, M. Linear-mixing model for shock-compressed liquid deuterium. United States: N. p., 1998. Web. doi:10.1103/PhysRevB.58.669.
Ross, M. Linear-mixing model for shock-compressed liquid deuterium. United States. https://doi.org/10.1103/PhysRevB.58.669
Ross, M. 1998. "Linear-mixing model for shock-compressed liquid deuterium". United States. https://doi.org/10.1103/PhysRevB.58.669.
@article{osti_638786,
title = {Linear-mixing model for shock-compressed liquid deuterium},
author = {Ross, M},
abstractNote = {A model has been developed for the equation of state of deuterium that builds in the correct limiting behavior for the molecular fluid at low pressure and extends smoothly through dissociation to the very high-density monatomic-metallic fluid. The key assumption is that the Helmholtz free energy of the dissociating mixture is a function that can be approximated by the composition average of the free energy of the pure molecular and metallic hydrogen equations of state. The composition is determined by minimizing the free energy. In comparison to earlier studies this model leads to an enhancement of molecular dissociation and a lowering of shock temperatures and pressures. Calculations for shock-compressed liquid deuterium are in agreement with experiments to a pressure of 2.1 Mbar. At about 1 Mbar and 20thinsp000 K liquid deuterium is 90{percent} dissociated and is a nearly degenerate metal. The model predicts that molecular dissociation will lead to negative values of ({partial_derivative}P/{partial_derivative}T){sub V} in the range 4000 to 10thinsp000 K and volumes below 7 cc/mol. This feature suggests the formation of covalently bonded species in the partially dissociated mixture. {copyright} {ital 1998} {ital The American Physical Society}},
doi = {10.1103/PhysRevB.58.669},
url = {https://www.osti.gov/biblio/638786}, journal = {Physical Review, B: Condensed Matter},
number = 2,
volume = 58,
place = {United States},
year = {Wed Jul 01 00:00:00 EDT 1998},
month = {Wed Jul 01 00:00:00 EDT 1998}
}