Spill-Out and Spill-In

  • Ideally,  neutrino capture, neutron emission, positron annihilation, and gadolinium neutron capture all happen in the target.
  • Taking the possibility of one of these events happening in the  γ-catcher into account, there are two things that can happen.
  • Spill-out, when gadolinium neutron capture occurs in the γ-catcher after a neutrino capture in the target, and spill-in, when gadolinium neutron capture occurs in the target after a neutrino capture in the γ-catcher, can skew the data.
  •  Having the two detectors from the buffer layer inward as symmetric as possible will ensure that spill-out and spill-in have no ill effect on data accuracy.