The Sign of the Magnetic Moment of theK39Nucleus

Abstract

The assignment of quantum numbers to the magnetic levels of alkali atoms depends on the sign of the nuclear magnetic moment. If a beam of normal alkali atoms is split in a weak inhomogeneous magnetic field and transitions are then induced among the component magnetic levels, a subsequent strong field analysis of a selected state suffices to identify its quantum numbers and hence to determine the sign of the moment. This method applied to ${\mathrm{K}}^{39}$ determines its nuclear magnetic moment to be positive in contradiction to the findings of Jackson and Kuhn from h.f.s. data. A similar experiment on ${\mathrm{Na}}^{23}$ shows its nuclear moment to be positive in agreement with the h.f.s. result of Granath and Van Atta.