Hannover 2003 – wissenschaftliches Programm
Q 45.7: Poster
Donnerstag, 27. März 2003, 16:30–18:30, Lichthof
Optical Measurement of the 2S Hyperfine Interval in Atomic Hydrogen in a Near-to-Zero Magnetic Field — •N. Kolachevsky1,2, M. Fischer1, S.G. Karshenboim1,3, and T.W. Hänsch1,4 — 1Max-Planck-Institut für Quantenoptik, Garching — 2P.N. Lebedev Physics Institute, Moscow, Russia — 3D.I. Mendeleev Institute for Metrology, St. Petersburg, Russia — 4Ludwig-Maximilians-Universität München
We report on a preliminary result of a precision optical measurement of the 2S hyperfine interval in atomic hydrogen. In a weak external magnetic field it is possible to derive this interval as a frequency difference between two optical two-photon transitions excited between corresponding 1S and 2S hyperfine levels. The interval was found to be 177 556 846 (12) Hz which is the most precise measurement of this interval to date. Pressure shift of this interval is presently under investigation. The theoretical evaluation of the combination of 1S and 2S hyperfine intervals D21theor= 49 953(3) Hz is in a good agreement with the D21 value deduced from this measurement.