A Quantitative Determination of the Magnetic Moment of the Neutron in Units of the Proton Moment

Abstract

A precision determination of the ratio of the magnetic moments of neutron and proton is presented. The method consists in determining the Larmor precession frequencies of neutrons and protons simultaneously in the same extremely homogeneous magnetic field. In this manner the ratio of the two Larmor frequencies gives directly the ratio of the two magnetic moments. The precession frequency of the neutrons is obtained by the occurrence of non-adiabatic transitions of a polarized neutron beam, the precession frequency of the protons by nuclear induction. Measurements are made so that only small differences in frequency have to be measured in terms of a constant but otherwise unknown standard. The value of the ratio of the two moments is found to be $\frac{|{\ensuremath{\mu}}_{N}|}{{\ensuremath{\mu}}_{P}}=0.685001\ifmmode\pm\else\textpm\fi{}0.00003$. By use of this value in connection with the recent determination of the ratio of the moments of proton and deuteron by Bloch, Levinthal, and Packard, the deviation of the deuteron moment from additivity is found to be 0.02230\ifmmode\pm\else\textpm\fi{}0.00009 nuclear magnetons.