Hyperfine splitting and isotope shift in the atomic D-2 line of Na-22,Na-23 and the quadrupole moment of Na-22

The hyperfine structure of the D-2 optical line in Na-22 and Na-23 has been investigated using high resolution laser spectroscopy of a well-collimated atomic beam. The hyperfine splitting constants A and B for the excited 3p P-2(3/2) level for both investigated sodium isotopes have been obtained. Th ey are as follows: A(22) = 7.31(4) MHz, B(22) = 4.71(28) MHz, A(23) = 18.57 2(24) MHz, B(23) = 2.723(55) MHz. With this data, using the high precision MCHF calculations for the electric field gradient at the nucleus, the elect ric quadrupole moment of Na-22 has been deduced: Q(s)(22) = +0.185(11) b. T he sign of Q(s)(22), determined for the first time, indicates a prolate nuc lear deformation. A precise value of the isotope shift Na-22,Na-23 in the D -2 line has also been obtained.