Energy and angular distribution of photo-neutrons for 16.6 MeV polarized photon on medium–heavy targets

The energy spectra as well as the angular distribution of photo-neutrons, called the double differential cross sections (DDXs) of the ($\gamma$, xn) reaction were measured for 16.6 MeV linearly polarized photons on Pb, Au, Sn, Cu, Fe, and Ti targets. Polarized photons were prepared using the laser Compton scattering technique at BL01, NewSUBARU, Hyogo, Japan. The photo-neutrons were measured using liquid organic scintillators, placed at six different angles. The time-of-flight technique was used to determine the neutron energy. The low energy and high energy components on the DDXs were identified for all the targets. Flat angular dependence was observed for the low energy component; however, a cos(2$\Theta$) distribution was observed for the high energy component, where $\Theta$ is the angle between the photon polarization direction and neutron emission. The angular dependences were parameterized by fitting the experimental data. The obtained parameters were compared with those from previous studies conducted decades ago.