Leon Chao

Publications

The Design and Development of a Tabletop Kibble Balance at NIST

May 23, 2019

Author(s):

Leon S. Chao, Frank C. Seifert, Darine El Haddad, Julian Stirling, David B. Newell, Stephan Schlamminger

On November 16, 2018, the 26th General Conference on Weights and Measures (CGPM) voted unanimously to revise the International System of Units (SI) from a...

The Design and Development of a Tabletop Kibble Balance at NIST

March 20, 2019

Author(s):

Leon S. Chao, Frank C. Seifert, Darine El Haddad, Stephan Schlamminger

A global paradigm shift to redefine the International System of Units (SI) from a system based on seven fundamental units to seven fundamental constants is...

Measurement of the Planck constant at the National Institute of Standards and Technology from 2015 to 2017

July 28, 2017

Author(s):

Darine El Haddad, Frank C. Seifert, Leon S. Chao, Antonio M. Possolo, David B. Newell, Jon R. Pratt, Carl J. Williams, Stephan Schlamminger

Researchers at the National Institute of Standards and Technology(NIST) estimate the value of the Planck constant as h = 6.62606994(10) x 10^-34 Js, hence with...

Bridging classical and quantum mechanics

September 28, 2016

Author(s):

Darine El Haddad, Frank C. Seifert, Leon S. Chao, Shisong Lee, David B. Newell, Jon R. Pratt, Carl J. Williams, Stephan Schlamminger

Using a watt balance and a frequency comb, a mass-energy equivalence is derived. The watt balance compares mechanical power measured in terms of the meter, the...

A precise instrument to determine the Planck constant, and the future kilogram

June 21, 2016

Author(s):

Darine El Haddad, Frank C. Seifert, Leon S. Chao, David B. Newell, Jon R. Pratt, Carl J. Williams, Stephan Schlamminger, Shisong Li

A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second and the kilogram to electrical power measured...