Helium 23P fine structure measurement in a discharge cell

T. Zelevinsky, D. Farkas, G. Gabrielse

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A precise measurement of helium 23P fine structure was carried out in a discharge cell using Doppler-free laser spectroscopy. It is the only known experiment to directly measure all three fine structure intervals at a 1 kHz level of accuracy. The 23P1 - 23P 2 interval value agrees with other experiments but disagrees with theoretical predictions of two-electron QED. When this disagreement is resolved, the 23P0 - 23P1 interval measurement reported here will allow a determination of the fine structure constant to 14 parts in 109, surpassing the precision of the well known QED-independent quantum Hall effect and Josephson effect determinations. The discharge cell is shown to be advantageous in the study and correction of systematic frequency shifts related to light pressure, and the use of the cell ensures that the possible systematic errors are substantially different from those reported in other experiments.

Original languageEnglish (US)
Title of host publicationLaser Spectroscopy - Proceedings of the 17th International Conference, ICOLS 2005
PublisherWorld Scientific Publishing Co. Pte Ltd
Number of pages11
ISBN (Print)9789812566591
StatePublished - Jan 1 2005
Event17th International Conference on Laser Spectroscopy, ICOLS 2005 - Aviemore, United Kingdom
Duration: Jun 19 2005Jun 24 2005


Other17th International Conference on Laser Spectroscopy, ICOLS 2005
CountryUnited Kingdom

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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