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James A. Fedchak (Fed)

Jim Fedchak has been with NIST since 2003. He leads the vacuum project, which includes realizing and disseminating absolute pressures from 10-7 Pa to 30 Pa, and low gas flow from 10-12 mol/s to 10-6 mol/s. He is directly responsible for ionization gauge calibrations and spinning rotor gauge calibrations. Jim's knowledge of vacuum science and technology covers a variety of applications derived from his previous work experience. Previously, Jim worked with the Low-background Infrared Radiation project at NIST doing cryogenic infrared radiometry; worked in the photonics industry with New Focus Inc.; performed atomic spectroscopy at the University of Wisconsin; and developed spin-polarized targets at Argonne National Laboratory. He has a PhD in experimental atomic and molecular physics from the College of William and Mary. He has numerous publications in all of these fields. Jim is a member of the Low Pressure Working Group of the CCM, and is presently a member of the AVS Vacuum Technology Division Committee.

Publications

Precise Quantum Measurement of Vacuum with Cold Atoms

Author(s)
Daniel Barker, Bishnu Acharya, James A. Fedchak, Nikolai Klimov, Eric Norrgard, Julia Scherschligt, Eite Tiesinga, Stephen Eckel
We describe the cold-atom vacuum standards (CAVS) under development at the National Institute of Standards and Technology. The CAVS measures pressure in the

A constant pressure flowmeter for the extremely high vacuum

Author(s)
Stephen Eckel, Daniel Barker, James A. Fedchak, Emmanuel Newsome, Julia Scherschligt, Robert E. Vest
We demonstrate operation of a constant-pressure flowmeter capable of generating and accurately measuring flows as low as $1\times10^-13}$mol/s. Generation of

Comparison of two multiplexed portable cold atom vacuum standards

Author(s)
Lucas Ehinger, Bishnu Acharya, Daniel Barker, James A. Fedchak, Julia Scherschligt, Eite Tiesinga, Stephen Eckel
We compare the vacuum measured by two portable cold atom vacuum standards (pCAVS) based on ultracold $^7$Li atoms. Our pCAVS devices share the same laser system

Patents (2018-Present)

Optomechanical Pressure Measurement System And Method Using The Vibrational Modes Of A Membrane

NIST Inventors
Stephen Eckel , James A. Fedchak , Thomas Purdy and Robinjeet Singh
An optomechanical pressure-measurement system measures pressure in the range of 10.sup.−6 Pa-10.sup.−2 Pa by measuring various properties of a vibrational mode of an ultra-thin membrane member. With independent measurements of the thickness and density of the membrane, in addition to the measured

Uniaxial Counter-Propagating Monolaser Atom Trap

NIST Inventors
Stephen Eckel , James A. Fedchak , Julia Scherschligt , Daniel Barker , Eric Norrgard and Nikolai Klimov
A uniaxial counter-propagating monolaser atom trap cools and traps atoms with a single a laser beam and includes: an atom slower that slows atoms to form slowed atoms; an optical diffractor including: a first diffraction grating that receives primary light and produces first reflected light; a
Created October 9, 2019, Updated December 8, 2022