Continuous-wave measurement of the 1S-2S transition frequency in atomic hydrogen: the 1S Lamb shift

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5376077

Beausoleil, R G

The 1S-2S transition frequency in atomic hydrogen was measured with a precision of 6 parts in 10/sup 10/ by continuous-wave Doppler-free two-photon spectroscopy. Cavity-enhanced multimilliwatt radiation near 243 nm produced by sum-frequency generation was employed and the 1S-2S transition was observed in a low-pressure hydrogen/helium cell with a resolution of 3 parts in 10/sup 9/. For a frequency comparison, an optical heterodyne signal was detected at the difference frequency between the 243-nm light used to excite the 1S-2S transition and the second harmonic of a reference laser locked to an interferometrically calibrated /sup 130/Te/sub 2/ absorption line near 486 nm. Choosing a value of the Rydberg constant measured independently by high-resolution spectroscopy of the hydrogen Balmer-..beta.. transition, the hydrogen ground-state Lamb shift was found to be 8 173.3(1.7) MHz, in good agreement with the theoretical value of 8 173.06(16) MHz calculated by Johnson and Soff. The 1S-2S transition has an unusually narrow natural linewidth of 1.3 Hz, offering an eventual experimental resolution of 5 parts in 10/sup 16/. The author proposes Doppler-free two-photon optical Ramsey spectroscopy of cold atoms falling freely because of gravity as a means of achieving this objective.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 5376077
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BALMER LINES
ELEMENTS
ENERGY-LEVEL TRANSITIONS
FUNDAMENTAL CONSTANTS
HYDROGEN
LAMB SHIFT
LINE WIDTHS
NONMETALS
RYDBERG CONSTANT
SPECTRAL SHIFT