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Search Publications by: James A. Fedchak (Fed)

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Displaying 26 - 50 of 93

Note: A Bitter-type electromagnet for complex atomic trapping and manipulation

February 12, 2021
Author(s)
Jacob L. Siegel, Daniel Barker, James A. Fedchak, Julia Scherschligt, Stephen Eckel
We create a pair of symmetric Bitter-type electromagnet assemblies capable of producing multiple field configurations including uniform magnetic fields, spherical quadruple traps, or Ioffe-Pritchard magnetic bottles. Unlike other designs, our coil allows

Note: A Radio Frequency Voltage-Controlled Current Source for Quantum Spin Manipulation

October 19, 2020
Author(s)
Daniel S. Barker, Alessandro Restelli, James A. Fedchak, Julia K. Scherschligt, Stephen P. Eckel
We present a design for a wide-bandwidth, voltage-controlled current source that is easily integrated with radiofrequency magnetic field coils. Our design uses current feedback to compensate for the frequency-dependent impedance of a radiofrequency antenna

A wide-bandwidth, high-power radio-frequency driver for acousto-optic and electro-optic devices

August 6, 2019
Author(s)
Daniel S. Barker, Neal C. Pisenti, Alessandro Restelli, Julia K. Scherschligt, James A. Fedchak, Gretchen K. Campbell, Stephen P. Eckel
We present a design for a general-purpose radio-frequency amplifier circuit that is suitable for driving acousto-optic and electro-optic devices. Our design uses telecom amplifiers to achieve power output > 1 W over a 10 MHz to 1.1 GHz frequency range, and

Nuclear-Spin Dependent Parity Violation in Optically Trapped Polyatomic Molecules

July 3, 2019
Author(s)
Eric B. Norrgard, Daniel S. Barker, Stephen P. Eckel, James A. Fedchak, Nikolai N. Klimov, Julia K. Scherschligt
We investigate using optically trapped linear polyatomic molecules as probes of nuclear spin- dependent parity violation. The presence of closely spaced, opposite-parity $\ell$-doublets is a general feature of such molecules, allowing parity-violation

A single-beam slower and magneto-optical trap using a nanofabricated grating

June 11, 2019
Author(s)
Daniel S. Barker, Eric B. Norrgard, Nikolai N. Klimov, James A. Fedchak, Julia K. Scherschligt, Stephen P. Eckel
We demonstrate a compact (0.25 L) system for laser cooling and trapping atoms from a heated dispenser source. Our system uses a nano-fabricated diffraction grating to generate a magneto- optical trap (MOT) using a single input laser beam. An aperture in

Light-induced atomic desorption of lithium

October 8, 2018
Author(s)
Daniel S. Barker, Eric B. Norrgard, Julia K. Scherschligt, James A. Fedchak, Stephen P. Eckel
We demonstrate loading of a Li magneto-optical trap using light-induced atomic desorption. The magneto-optical trap confines up to approximately 10000 lithium atoms with loading rates up to 4000 atoms/s. We study the Li desorption rate as a function of the

Challenges to miniaturizing cold atom technology for deployable vacuum metrology

September 14, 2018
Author(s)
Stephen P. Eckel, Daniel S. Barker, James A. Fedchak, Nikolai N. Klimov, Eric B. Norrgard, Julia K. Scherschligt, Constantinos Makrides, Eite Tiesinga
Cold atoms are excellent metrological tools; they currently realize SI time and, soon, SI pressure in the ultra-high (UHV) and extreme high vacuum (XHV) regimes. The development of primary, vacuum metrology based on cold atoms currently falls under the

Quantum-based vacuum metrology at NIST

June 20, 2018
Author(s)
Julia K. Scherschligt, James A. Fedchak, Zeeshan Ahmed, Daniel S. Barker, Kevin O. Douglass, Stephen P. Eckel, Edward T. Hanson, Jay H. Hendricks, Thomas P. Purdy, Jacob E. Ricker, Robinjeet Singh
The measurement science in realizing and disseminating the SI unit for pressure, the pascal (Pa), has been the subject of much interest at NIST. Modern optical-based techniques for pascal metrology have been investigated, including multi-photon ionization

Recent Developments in Surface Science and Engineering, Thin Films, Nanoscience, Biomaterials, Plasma Science, and Vacuum Technology

May 31, 2018
Author(s)
Miran Mozetic, Alenka Vesel, Gregor Primc, J. Bauer, A. Eder, G. H. S. Schmid, David Ruzic, Zeeshan Ahmed, Daniel Barker, Kevin O. Douglass, Stephen Eckel, James A. Fedchak, Jay H. Hendricks, Nikolai Klimov, Jacob Edmond Ricker, Julia Scherschligt, Jack A. Stone Jr., Gregory F. Strouse, I. Capan, M Buljan, S. Milosevic, C Teichert, S R. Cohen, A G. Silva, M Lehocky, P Humpolicek, C Rodriguez, J Hernandez-Montelongo, E Punzon-Quijorna, D Mercier, M Manso-Silvan, G Ceccone, A Galtayries, K Stana-Kleinschek, I Petrov, J E. Greene, J Avila, C Y. Chen, B Caja, H Yi, A Boury, S Lorcy, M C. Asensio, T Gans, D O?Connell, F Reniers, A Vincze, M Anderle
Nanometer-sized structures, surfaces and sub-surface phenomena have played an enormous role in science and technological applications and represent a driving-force of current interdisciplinary science. Recent developments include the atomic-scale

A 3D-printed alkali metal dispenser

May 1, 2018
Author(s)
Eric B. Norrgard, Daniel S. Barker, James A. Fedchak, Nikolai N. Klimov, Julia K. Scherschligt, Stephen P. Eckel
We demonstrate and characterize a source of Li atoms made from direct metal laser sintered Ti. The source's outgassing rate is measured to be $5 \,(2)\cdot 10^{-7}$\,$\rm{Pa}~ \rm{L}~ \rm{s}^{-1}$ at the temperature which optimizes the number of atoms

Recommended practice for calibrating vacuum gauges of the ionization type

April 27, 2018
Author(s)
James A. Fedchak, Patrick J. Abbott, Jay H. Hendricks, Paul C. Arnold, Neil T. Peacock
This document represents a recommended practice for the calibration of ionization gauges using the comparison method. In this method, ionization gauges are compared to a working standard that has an SI traceable calibration. The ionization gauge is either

3D printed ABS-MOF composite materials and their gas storage properties

March 19, 2018
Author(s)
Michael Bible, Makfir Sefa, Julia Scherschligt, Zeeshan Ahmed, James A. Fedchak, Hartings Mathew
Metal organic framework materials (MOFs) have been primarily recognized for their ability to promote selective storage of gas molecules. In their as-synthesized (powdered) form, MOFs are not easily processed for use in end-devices where their properties
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