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Precise Quantum Measurement of Vacuum with Cold Atoms
Published
Author(s)
Daniel Barker, Bishnu Acharya, James A. Fedchak, Nikolai Klimov, Eric Norrgard, Julia Scherschligt, Eite Tiesinga, Stephen Eckel
Abstract
We describe the cold-atom vacuum standards (CAVS) under development at the National Institute of Standards and Technology. The CAVS measures pressure in the ultra-high and extreme-high vacuum regimes by measuring the loss rate of sub-millikelvin sensor atoms from a magnetic trap. Ab-initio quantum scattering calculations of cross sections and rate coefficients relate the density of background gas molecules or atoms to the loss rate of ultra-cold sensor atoms. The resulting measurement of pressure through the ideal gas law is traceable to the second and the kelvin, making it a primary realization of the pascal. At NIST, two versions of the CAVS have been constructed: a laboratory standard used to achieve the lowest possible uncertainties and pressures and a portable version that is a potential replacement for the Bayard-Alpert ionization gauge. Both types of CAVSs are connected to a combined extreme-high vacuum flowmeter and dynamic expansion system to enable sensing of a known pressure of gas. In the near future, we anticipate being able to compare the laboratory scale CAVS, the portable CAVS, and the flowmeter/dynamic expansion system to validate the operation of the CAVS as both a standard and vacuum gauge
Barker, D.
, Acharya, B.
, Fedchak, J.
, Klimov, N.
, Norrgard, E.
, Scherschligt, J.
, Tiesinga, E.
and Eckel, S.
(2022),
Precise Quantum Measurement of Vacuum with Cold Atoms, Review of Scientific Instruments, [online], https://doi.org/10.1063/5.0120500, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935360
(Accessed October 9, 2025)