Small-Angle Elastic Scattering of Fast Neutrons and the Electric Polarizability of the Neutron

The differential cross section for elastic scattering of 0.57-MeV neutrons by uranium was measured at seven angles between 3.6° and 18° to a relative accuracy of about 4%. After subtraction of the Schwinger scattering contribution, the data show no evidence of enhanced small-angle scattering such as that previously observed at higher energies by Aleksandrov and by Dukarevich and Dyumin. The present data are consistent with an electric polarizability $\alpha$ of the neutron of less than 2×${10}^{-40\mathrm{}}$ ${\mathrm{cm}}^3$. As this upper limit to $\alpha$ is smaller than the value needed to account for the anomalous small-angle scattering reported by Aleksandrov and by Dukarevich and Dyumin, it is concluded that the enhanced scattering is not produced by an electric polarizability of the neutron.