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PUBLICATIONS

The Polarizability of Helium and Gas Metrology

Published

Author(s)

James W. Schmidt, R Gavioso, E May, Michael R. Moldover

Abstract

Using a quasi-spherical, microwave cavity resonator, we measured the refractive index of helium to deduce its molar polarizability Aε in the limit of zero density. We obtained (Aε,meas - Aε,theory)/Aε = (-1.8plus or minus} 8.4)× 10-6, where the standard uncertainty (8.4 ppm) is factor of 3.6 smaller than that of the best previous measurement. If the theoretical value of Ae is accepted, these data determine a value for the Boltzmann constant that is only (1.8 plus or minus} 8.4) ppm larger than the accepted value. Our techniques will enable a helium-based pressure standard and measurements of thermodynamic temperatures.
Citation
Physical Review Letters
Volume
98
Issue
06/22/07
Pub Type
Journals

Keywords

Boltzmann constant, dielectric constant, fundamental constant, helium, index of refraction, microwave resonator, polarizability, pressure standard, temperature standard
Thermometry metrology, Thermodynamics, Thermochemical properties, Standards, Metrology, Flow metrology and rheology, Chemistry, Chemical engineering and processing and Analytical chemistry

Citation

Schmidt, J. , Gavioso, R. , May, E. and Moldover, M. (2007), The Polarizability of Helium and Gas Metrology, Physical Review Letters (Accessed May 1, 2025)

Issues

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Created June 21, 2007, Updated October 12, 2021