Volume 76, Number 3, November 2006
|Page(s)||409 - 415|
|Section||Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics|
|Published online||29 September 2006|
Helium - metrology at
Laser Centre Vrije Universiteit - De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
2 Department of Applied Physics, Eindhoven University of Technology P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Accepted: 8 September 2006
An experiment is proposed to excite the “forbidden” - magnetic dipole () transition at in a collimated and slow atomic beam of metastable helium atoms. It is demonstrated that an excitation rate of can be realised with the beam of a 2 W narrow-band telecom fiber laser intersecting the atomic beam perpendicularly. A Doppler-limited sub-MHz spectroscopic linewidth is anticipated. Doppler-free excitation of 2% of trapped and cooled atoms may be realised in a one-dimensional optical-lattice geometry, using the 2 W laser both for trapping and spectroscopy. The very small (8 Hz) natural linewidth of this transition presents an opportunity for accurate tests of atomic structure calculations of the helium atom. A measurement of the 3He-4He isotope shift allows for accurate determination of the difference in nuclear charge radius of both isotopes.
PACS: 42.50.Xa – Optical tests of quantum theory / 31.30.Jv – Relativistic and quantum electrodynamic effects in atoms and molecules / 32.80.-t – Photon interactions with atoms
© EDP Sciences, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.