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Search Publications by: Gordon A. Shaw (Fed)

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Displaying 1 - 25 of 51

Gravimetric deposition of microliter drops with radiometric confirmation

September 9, 2023
Denis E. Bergeron, Richard Essex, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren, Ryan P. Fitzgerald
A manual gravimetric dispensing technique is demonstrated using a micropipettor modified for use with removeable microcapillaries. Liquid scintillation sources were prepared from a well-characterized 241Am reference solution, providing a radiometric check

Isotope Dilution Mass Spectrometry as an Independent Assessment for Mass Measurements of Milligram Quantities of Aqueous Solution

January 1, 2023
Richard Essex, Jacqueline L. Mann, Denis E. Bergeron, Ryan P. Fitzgerald, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren
Isotope dilution mass spectrometry was used to independently assess the accuracy of mass measurement methods developed to quantitatively dispense milligram quantities of aqueous solution. Solutions of isotopically enriched 158Gd and enriched 155Gd were

Proceedings of EUSPEN 2022

October 26, 2022
Sven Schulze, Kumar Arumugam, Rene Theska, Gordon A. Shaw
The 2019 redefinition of the kilogram in the International System of Units (SI) connects the unit of mass with Planck's constant (h) through electrical metrology by means of precision balances. This not only changes the way the mass is defined, but also


May 22, 2022
Gordon A. Shaw
Quantitative dispensing of liquids by mass becomes increasingly difficult as sample volume decreases. Whereas milliliter quantities of liquid can be directly weighed as dispensed on an analytical balance or using pycnometer methods, microliter samples are

Toward a New Primary Standardization of Radionuclide Massic Activity Using Microcalorimetry and Quantitative Milligram-Scale Samples

February 24, 2022
Ryan P. Fitzgerald, Bradley Alpert, Dan Becker, Denis E. Bergeron, Richard Essex, Kelsey Morgan, Svetlana Nour, Galen O'Neil, Dan Schmidt, Gordon A. Shaw, Daniel Swetz, R. Michael Verkouteren, Daikang Yan
We present a new paradigm for the primary standardization of radionuclide activity per mass of solution (Bq/g). Two key enabling capabilities are 4π decay-energy spectrometry using chip-scale sub-Kelvin microcalorimeters and direct realization of mass by

Comparison of electrostatic and photon pressure force references at the nanonewton level

May 3, 2021
Gordon Shaw, John A. Kramar, Paul Williams, Matthew Spidell, Richard Mirin, Julian Stirling
This work describes a comparison between nanonewton force references derived from an electrostatic force balance and photon pressure force from calibrated laser optical power in the 1 watt range. The NIST Electrostatic Force Balance (EFB) is used to

Scaling of Mass and Force Using Electrical Metrology

May 3, 2021
Gordon Shaw
The impending redefinition of the International System of Units (SI) allows realization of the kilogram using electrical metrology. It can be shown that electrical metrology can also be used to scale mass using electrostatic forces. An approach to mass

Design of an electrostatic balance to measure optical power of 100 kW

February 19, 2021
Lorenz Keck, Gordon A. Shaw, Renee Theska, Stephan Schlamminger
To accommodate the need for increased portability and accuracy in laser power measurement instrumentation above 100 Watt at the National Institute of Standards and Technology (NIST), a new instrument is required. This instrument is intended to create a new

Simplified kilogram traceability for photon momentum radiometers

October 1, 2020
Kyle A. Rogers, Paul A. Williams, Gordon A. Shaw, John H. Lehman
High power laser applications in areas such as laser processing of materials can require an accurately measured laser power. Radiation pressure-based laser power measurement has been proven as a practical method for quantifying these high-power levels in

Using Radiation Pressure to Develop a Radio-Frequency Power Measurement Technique Traceable to the Redefined SI

October 15, 2018
Christopher L. Holloway, Matthew T. Simons, David R. Novotny, John H. Lehman, Paul A. Williams, Gordon A. Shaw
We discuss a power measurement technique traceable to the International System of Units based on radiation pressure (or radiation force) carried by an electromagnetic wave. A measurement of radiation pressure offers the possibility for a power measurement

MEMS non-absorbing electromagnetic power sensor employing the effect of radiation pressure

September 8, 2018
Ivan Ryger, Aly Artusio-Glimpse, Paul A. Williams, Gordon A. Shaw, Matt Simons, Christopher L. Holloway, John H. Lehman
We demonstrate a compact electromagnetic power sensor based on force effects of electromagnetic radiation onto a highly reflective mirror surface. Unlike the conventional power measurement approach, the photons are not absorbed and can be further used in

Milligram mass metrology using an electrostatic force balance

September 28, 2016
Gordon A. Shaw, Julian Stirling, John A. Kramar, Alexander D. Moses, Patrick J. Abbott, Richard L. Steiner, Andrew D. Koffman, Jon R. Pratt, Zeina J. Kubarych
Although mass is typically defined within the International System of Units (SI) at the Kilogram level, the pending redefinition of the SI provides an opportunity to realize mass at any scale using electrical metrology. We propose the use of an

Optomechanical Motion Sensors

July 8, 2015
Felipe Guzman, Oliver Gerberding, John T. Melcher, Julian Stirling, Jon R. Pratt, Gordon A. Shaw, Jacob M. Taylor
Compact optical cavities can be combined with motion sensors to yield unprecedented resolution and SI-traceability in areas such as acceleration sensing and atomic force microscopy AFM, among others. We have incorporated Fabry-Perot fiber-optic micro

A self-calibrating optomechanical force sensor with femtonewton resolution

December 10, 2014
John T. Melcher, Julian Stirling, Felipe Guzman, Jon R. Pratt, Gordon A. Shaw
We report the development of an ultrasensitive optomechanical sensor designed to improve the accuracy and precision of force measurements with atomic force microscopy. The sensors achieve quality factors of 4.3x10^6 (a 100-fold improvement over quartz

Progress toward Radiation-Pressure-Based Measurement of High-Power Laser Emission - Under Policy Review

October 6, 2014
Paul A. Williams, Joshua A. Hadler, Daniel King, Robert Lee, Frank C. Maring, Gordon A. Shaw, Nathan A. Tomlin, John H. Lehman, Marla L. Dowell
We present an overview of our efforts toward using optical radiation pressure as a means to measure optical power from high-power lasers. Early results with measurements ranging from tens of watts to 92 kW prove the concept, but validation uncertainties

Milligram Mass Metrology Using Electrostatics

August 25, 2014
Gordon A. Shaw, John A. Kramar
— Although mass has historically been defined using an artifact standard, other means of realization are possible. One alternative approach employs a precision electromechanical balance, using the SI electrical units to derive a force used to measure the

Electrochemical Micromachining of NiTi Shape Memory Alloys with Ultrashort Voltage Pulses

December 8, 2011
Joseph Maurer, John Hudson, Steven E. Fick, Thomas P. Moffat, Gordon A. Shaw
Electrochemical micromachining (ECMM) with ultrashort voltage pulses has been used to fabricate microstructures on a NiTi shape memory alloy (SMA). Because of its unique properties, NiTi is a desirable material for use in various applications including

Calibration of dynamic sensors for noncontact-atomic force microscopy

August 12, 2011
Gordon A. Shaw, Jon R. Pratt, Zeina J. Kubarych
Access to quantitative information on surface forces in noncontact-atomic force microscopy (NC-AFM) requires the accurate calibration of several key sensor parameters. This work outlines a dynamic method for calibrating the spring constant of tuning fork

Nanomechanical standards based on the intrinsic mechanics of molecules and atoms

June 7, 2010
Jon R. Pratt, Gordon A. Shaw, Douglas T. Smith
For more than a decade, instruments based on local probes have allowed us to touch objects at the nanoscale, making it possible for scientists and engineers to probe the electrical, chemical, and physical behaviors of matter at the level of individual