On the Precision Measurement of Nuclear Magnetic Moments by the Molecular Beam Magnetic Resonance Method. The Moments of ${\mathrm{H}}^1$, ${\mathrm{Li}}^7$, ${\mathrm{F}}^{19}$, and ${\mathrm{Na}}^{23}$

A direct comparison of nuclear magnetic moments with the electronic moment is made. This is done by the measurement of the Larmor precession frequency of the nucleus and the frequencies of some of the lines of the radiofrequency spectra of the alkali atoms in the same magnetic field. In this way the magnetic moment of the proton is found to be 2.7896±0.0008 nuclear magnetons. The precision of this value is very much greater than that which has heretofore been obtained by measurement of magnetic field by usual methods. The same methods are used in a redetermination of the magnetic moments of ${\mathrm{Li}}^7$, ${\mathrm{F}}^{19}$ and ${\mathrm{Na}}^{23}$. Since the nuclear gyromagnetic ratio of ${\mathrm{Li}}^7$ has previously served as a standard in terms of which other $g$ values were expressed, an improvement in the precision of this $g$ value makes it possible to restate, with improved precision, the $g$ values and magnetic moments of other nuclei.