Speed of Sound in Helium-4 from Ab Initio Acoustic Virial Coefficients

2021 ◽  
Author(s):  
Navneeth Gokul ◽  
Andrew J. Schultz ◽  
David A. Kofke
Keyword(s):  
Ab Initio ◽  
Speed Of Sound ◽  
Virial Coefficients ◽  
Helium 4

Semiclassical fifth virial coefficients for improved ab initio helium-4 standards

2012 ◽  
Vol 531 ◽  
pp. 11-17 ◽  
Author(s):  
Katherine R.S. Shaul ◽  
Andrew J. Schultz ◽  
David A. Kofke ◽  
Michael R. Moldover
Keyword(s):  
Ab Initio ◽  
Virial Coefficients ◽  
Helium 4

Path-integral Mayer-sampling calculations of the quantum Boltzmann contribution to virial coefficients of helium-4

2012 ◽  
Vol 137 (18) ◽  
pp. 184101 ◽  
Author(s):  
Katherine R. S. Shaul ◽  
Andrew J. Schultz ◽  
David A. Kofke
Keyword(s):  
Path Integral ◽  
Virial Coefficients ◽  
Helium 4

Calculation of Thermodynamical, Transport and Structural Properties of Neon in Liquid and Supercritical Phases by Molecular Dynamics Simulations Using an Accurate ab initio Pair Potential

2003 ◽  
Vol 68 (3) ◽  
pp. 627-643 ◽  
Author(s):  
Muthusamy Venkatraj ◽  
Markus G. Müller ◽  
Hanspeter Huber ◽  
Robert J. Gdanitz
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Structural Properties ◽  
Pair Potential ◽  
Virial Coefficients ◽  
Energy Curve ◽  
Second Virial Coefficients ◽  
Analytical Potential ◽  
Supercritical Phase ◽  
Dynamics Simulations

An analytical potential energy curve (NE3) is constructed from points obtained by accurate ab initio calculations. The quality of the pair potential is established by a comparison of calculated and experimental second virial coefficients as a function of temperature. Molecular dynamics equilibrium simulations are performed with the NE3 potential for pressures between 20 and 1000 MPa and temperatures between 100 and 600 K in the supercritical phase and for one point in the liquid phase of neon. The properties are compared with those obtained from experiment. It is found that the accurate pair potential has a large effect on pressure, energies and enthalpies and a significant influence on other thermodynamic properties but little influence on transport and structural properties. In the supercritical phase the deviation between the calculated quantum-corrected and experimental pressure values is always less than 2%.

Second Virial Coefficients of Ground State Nitrogen Atoms

1976 ◽  
Vol 31 (12) ◽  
pp. 1722-1724 ◽  
Author(s):  
C. Guidotti ◽  
G. P. Arrighini ◽  
M. Capitelli ◽  
U. T. Lamanna
Keyword(s):  
Ab Initio ◽  
Ground State ◽  
Virial Coefficients ◽  
Nitrogen Molecule ◽  
Repulsive Potential ◽  
Second Virial Coefficients ◽  
Temperature Range

Abstract Second virial coefficients of ground state nitrogen atoms have been calculated in the temperature range 6000 - 20000 K. The results have been obtained using experimental potentials for the states 1∑g+, 3∑u+5∑g+ and of the nitrogen molecule and an ab initio Heitler-London potential for the 2∑u+ repulsive potential. Differences up to a factor of 5 are found between the present second virial coefficients and the corresponding values of Kessel'man et al.

High-precision virial coefficients of argon and carbon dioxide from integration of speed of sound data in the pressure–temperature domain

2012 ◽  
Vol 110 (11-12) ◽  
pp. 1349-1358 ◽  
Author(s):  
Andrés F. Estrada-Alexanders ◽  
Orlando Guzmán ◽  
Brenda Pérez-Vidal
Keyword(s):  
Carbon Dioxide ◽  
High Precision ◽  
Speed Of Sound ◽  
Virial Coefficients ◽  
Sound Data

scholarly journals Helium-3 Purification System And Acoustic Cavity For Concentration Determination

2020 ◽  
Vol 21 (2) ◽  
Author(s):  
Carlos Banuelos Perez ◽  
Wenguang Jiang
Keyword(s):  
Data Analysis ◽  
Speed Of Sound ◽  
Room Temperature ◽  
Filtering Method ◽  
Acoustic Cavity ◽  
Concentration Determination ◽  
Helium 4 ◽  
Purification System ◽  
Sample Data ◽  
Helium 3

This paper discusses a filtering method of using differential adsorption to purify helium-3 (3He) from a helium-4 (4He) impurity. In addition, the paper discusses the precision of an acoustic cavity in determining the concentration of a mixture through measuring the speed of sound for a given sample. Data analysis will include measurements at room temperature in air at 1 atm, 4He at ≈ 1.2 x 105 Pa and 1.6 x 105 Pa, and Nitrogen at ≈ 1.0 x 105 Pa.

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