An experimental measurement of the electric dipole moment of the neutron by a neutron-beam magnetic resonance method is described. The result of the experiment is that the electric dipole moment of the neutron equals the charge of the electron multiplied by a distance $D=(-0.1\mathrm{}\pm 2.4)\times {10}^{-20\mathrm{}}$ cm. Consequently, if an electric dipole moment of the neutron exists and is associated with the spin angular momentum, its magnitude almost certainly corresponds to a value of $D$ less than 5×${10}^{-20\mathrm{}}$ cm.

• Received 17 May 1957

DOI:https://doi.org/10.1103/PhysRev.108.120