Schmidt, J.
, Gavioso, R.
, May, E.
and Moldover, M.
(2007),
The Polarizability of Helium and Gas Metrology, Physical Review Letters
(Accessed June 7, 2023)
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The Polarizability of Helium and Gas Metrology
Published
Author(s)
, R Gavioso, E May,
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
Citation
Created June 21, 2007, Updated October 12, 2021