Neutron Photoproduction from $^{139}$La Using 12-15 MeV Linearly Polarized $\gamma$-Rays

Data have been collected at the High Intensity $\gamma$-ray Source (HI$\gamma$S) to investigate neutron emission from a $^{139}$La target with linearly polarized gamma rays at $E_\gamma$= 12, 13, 14, and 15 MeV. Liquid scintillator detectors were placed at scattering angles of 55$^\circ$, 90$^\circ$ and 125$^\circ$ above, below and to the left and right of the target. Six additional detectors were placed at angles of 72$^\circ$, 107$^\circ$, and 142$^\circ$ above and to the right of the target. The ratio of neutron yields parallel to neutron yields perpendicular to the plane of polarization observed as a function of $E_n$, $E_\gamma$, and $\theta$ characterizes the response of the nucleus and may prove to be a useful observable in nuclear forensics. The results of the experiment will be discussed.