National Physical Laboratory

Laser Spectroscopy of Atomic Hydrogen: Absolute Frequency Measurements of the 2S-6S,6D Transitions

Further Information

Published: 23 May 2012

Authors: J. L. Flowers, P. W. Josephs-Franks, H. A. Klein, C. D.  Langham, H. S. Margolis, L. Wright, M. D. Plimmer, P. E. G. Baird and D. J. E. Knight

Related: Time and Frequency

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Hydrogen can provide a range of calculable reference frequencies, from the rf to the VUV, which are linked by welldefined atomic theory.

The Rydberg constant is determined by comparing measured transition frequencies in atomic hydrogen and deuterium to the theoretical expressions for the energy levels.

Although the 1S-2S transition frequency in hydrogen has been measured with an uncertainty of 1.4 parts in 1014 [2],
this is not sufficient to determine R∞ with higher accuracy.

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Last Updated: 1 Apr 2014
Created: 23 May 2012


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