Polarization and Differential Cross Section for Neutrons Scattered fromC12

Abstract

The polarization $P\left(\theta \right)$ and differential cross section $\sigma \left(\theta \right)$ for the scattering of neutrons of $0.1\le E_n\le 2.0$ MeV from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ have been measured at five or nine angles. $P\left(\theta \right)$ contains a slowly varying $sin\theta$ term and is dominated by a negative $sin2\theta$ term which grows strongly with energy so that $P\left(120\mathrm{}°\right)$ reaches as much as 40% at higher energies. The experimental values of $\sigma \left(\theta \right)$ and $P\left(\theta \right)$ are simultaneously described reasonably well over this energy range in terms of a two-level $R$-function formalism. Anomalous background effects are estimated by use of a square-well interaction potential.