Printer Friendly

Advancing the theory of the hydrogen atom. (News Briefs).

The hydrogen atom is the most basic atom from the point of view of atomic structure theory. Historically, efforts to understand its detailed properties have led to many advances in understanding fundamental physics. This atom is important not only as a model system that tests the limits of atomic theory and experiment, but it also provides information on fundamental physical constants, such as the Rydberg constant. In the past decade, the precision of the experiments has been improving rapidly, and improvements in the theory have been necessary to keep pace.

Over the past several years, a NIST-led project has carried out a precise calculation of the most basic quantum electrodynamic (QED) effect in the spectrum of hydrogen, namely the radiative process in which the atom emits and then reabsorbs a photon (the quantum of electromagnetic radiation). This process results in shifts of the atomic energy levels, which, in turn, affect the frequencies of light that are emitted and absorbed in experiments. The NIST work has led to a reduction of the uncertainty in the one-photon QED effect by over three orders of magnitude.

This accomplishment was made possible by a number of factors, including the high-performance computing resources at NIST and new developments in numerical analysis. The calculation required months of intensive, high-performance parallel computation.

This project was a collaboration between NIST, the Technical University of Dresden, and the University of Regensburg, both in Germany. The results have received wide recognition. For example, the project has been described as a "spectacular success" in Physics Reports, Vol. 342, p. 63 (2001).

CONTACT: Peter Mohr, (301) 975-3217; mohr@nist.gov.
COPYRIGHT 2002 National Institute of Standards and Technology
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2002, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Journal of Research of the National Institute of Standards and Technology
Article Type:Brief Article
Geographic Code:1USA
Date:Mar 1, 2002
Words:268
Previous Article:Coherence between nodes of a dual multiplexed trap. (News Briefs).
Next Article:NIST contributes to development of next generation multimedia standard MPEG-7. (News Briefs).
Topics:


Related Articles
First X-ray pattern of hydrogen solid.
Squeezed hydrogen turns semi-metallic.
Bouncing cold hydrogen atoms to a focus.
Iron swells up when squeezed with hydrogen.
Hydrogen can peel atoms off layer by layer.
The lightest metal in the universe; scientists make a fleeting metal from hydrogen.
Sticking tough with new hydrogen bonds.
Crystalline hydrogen gets its first X ray.
Hydrogen atoms chill to quantum sameness.
How about hydrogen?

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters