Back-Goudsmit Effect in Hfs ofNa233P32and the Electric Quadrupole Interaction Coefficient

Recent rf resonance experiments, at zero magnetic field, on the hfs of ${\mathrm{Na}}^{23}$ $3P_{\frac{3}{2}}$ left some doubt as to whether the value of the electric quadrupole coefficient, $b$, was 2.6 or -21.6 Mc/sec. It is pointed out that the doubt can be resolved by experiments under Back-Goudsmit coupling conditions, since a resonance curve showing four or three main maxima will be observed, respectively, according as $b=2.6\mathrm{} or -21.6\mathrm{}$ Mc/sec. Under these conditions too, the Landé factor can be measured. Preliminary experiments are reported which give a value of 1.34±0.02 for the Landé factor.