MEASUREMENT OF NA 5S(1 2) HYPERFINE SPLITTING BY IONIZATION USING A SAMPLE OF COLD ATOMS/

Hyperfine splitting of the 5S(1/2) state of sodium is measured using a sample of cold atoms held in a magneto-optical trap. Splitting determ ination is made through a nearly resonant two-photon excitation to the 5S(1/2) state followed by ionization. The laser employed has a sideba nd generated by an acousto-optic modulator that avoids the need of a p recise calibration of the laser scan. Ions are detected as a function of the laser frequency. We obtained Delta nu(HFS)(5S(1/2)) = 154.4 +/- 0.4 MHz. Comparison with previous results shows that the technique pr esented here is very promising for high precision measurements. (C) 19 98 Elsevier Science B.V. All rights reserved.