The hyperfine structure of the D2 optical line in 22Na and
23Na has been investigated using high resolution laser spectroscopy
of a well-collimated atomic beam. The hyperfine splitting constants
A and B for the excited 3p2P3/2 level for both investigated sodium
isotopes have been obtained. They are as follows: A(22)=7.31(4) MHz,
B(22)=4.71(28) MHz, A(23)=18.572(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 electric quadrupole moment
of 22Na has been deduced: Qs(22)=+0.185(11) b. The sign of Qs(22),
determined for the first time, indicates a prolate nuclear
deformation. A precise value of the isotope shift 22,23Na in the D2 line
has also been obtained