First measurement of the near-threshold2H(γ→,n)panalyzing power using a free-electron laser basedγ-ray source

Abstract

The first measurement of the ${}^{2}\mathrm{H}(\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}},n)p$ analyzing power near threshold has been performed using the High-Intensity Gamma-ray Source (HIGS) at the Duke Free-Electron Laser Laboratory. A 3.58 MeV $\ensuremath{\gamma}$-ray beam having an energy resolution of $2.5%$ and $100%$ linear polarization was incident on an active ${\mathrm{C}}_{6}{\mathrm{D}}_{12}$ target. Outgoing neutrons were detected parallel and perpendicular to the plane of $\ensuremath{\gamma}$-ray polarization at a lab angle of 150\ifmmode^\circ\else\textdegree\fi{}. The experimentally determined analyzing power provides a sensitive measurement of the relative $E1$ and $M1$ contributions to the total cross section.