A polyisotopic sodium beam produced by reactions of 20 GeV protons in an uranium target, was illuminated with a tunable cw dye laser. The atomic beam is analyzed by a six-pole magnet, ionized, and detected after selection of one isotope by use of a mass spectrometer. From the optical $D_1$ resonance lines the hyperfine structure, magnetic moments, and isotope shifts of ${}_{}{}^{21-31}{}_{}{}^{}\mathrm{Na}$ have been determined. The nuclear spins of ${}_{}{}^{26-30}{}_{}{}^{}\mathrm{Na}$ have been measured by magnetic resonance. The results are discussed in terms of nuclear deformation. The analysis of isotope shifts shows the presence of an appreciable volume shift contribution.

NUCLEAR STRUCTURE ${}_{}{}^{26-30}{}_{}{}^{}\mathrm{Na}$; measured $J$. ${}_{}{}^{21-31}{}_{}{}^{}\mathrm{Na}$; measured isotope shifts; deduced $\mu$. Atomic beam laser spectroscopy and magnetic resonance.

• Received 22 June 1978

DOI:https://doi.org/10.1103/PhysRevC.18.2342