  Understanding the neutron background is essential for determining the neutron
yield from nuclear reactions. In the analysis presented here, the shadow bars
are placed in front of neutron detectors to determine the energy dependent
neutron background fractions. The measurement of neutron spectra with and
without shadow bars is important to determine the neutron background more
accurately. The neutron background, along with its sources and systematic
uncertainties, are explored with a focus on the impact of background models and
their dependence on neutron energy.
