U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Daniel Barker ()

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 33 of 33

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

Vacuum Furnace for Degassing Stainless-Steel Vacuum Components

March 1, 2018
Author(s)
James A. Fedchak, Julia K. Scherschligt, Daniel S. Barker, Stephen P. Eckel, Alex P. Farrell, Makfir Sefa
Ultra-high vacuum systems must often be constructed of materials with ultra-low outgassing rates to achieve pressure of 10-6 Pa and below. In such a case, any component placed into the ultra-high vacuum system must also be constructed of materials with

Development of a new UHV/XHV pressure standard (Cold Atom Vacuum Standard)

November 10, 2017
Author(s)
Julia Scherschligt, James A. Fedchak, Daniel Barker, Stephen Eckel, Nikolai Klimov, Constantinos Makrides, Eite Tiesinga
The National Institute of Standards and Technology has recently begun a program to develop a primary pressure standard that is based on ultra-cold atoms, covering a pressure range of 1 × 10-6 Pa to 1 × 10-10 Pa and possibly lower. These pressures

Perspectives for a new realization of the pascal by optical methods

October 24, 2017
Author(s)
Jay H. Hendricks, Karl Jousten, Jack A. Stone Jr., Patrick F. Egan, Tom Rubin, Christof Gaiser, Rene Schodel, James A. Fedchak, Jacob E. Ricker, Jens Fluegge, Stephen P. Eckel, Julia K. Scherschligt, Daniel S. Barker, Kevin O. Douglass, Gregory F. Strouse, Uwe Sterr, Waldimir Sabuga
Since the beginning of measurement of pressure in the 17th century, the unit of pressure has been defined by the relationship of force per unit area. The present state of optical technology now offers the possibility of using a thermodynamic definition

An ultra-low noise, high-voltage piezo driver

December 8, 2016
Author(s)
Neal C. Pisenti, Alessandro Restelli, Ben J. Reschovsky, Daniel Barker, Gretchen K. Campbell
We present an ultra-low noise, high-voltage driver suited for use with piezoelectric actuators and other low- current applications. The architecture uses a flyback switching regulator to generate up to 250V in our current design, with an output of 1 kV or