Initial neutronic target station studies for the national spallation neutron source (NSNS)

Results found during initial NSNS target station neutronic design efforts are reported including the success of comparing neutron sources at 1 eV and moderator performance normalized to 1 eV. The usefulness of an analytic form is demonstrated. The angular dependence of the neutron current from a moderator face is presented together with the changes in neutron current with variation of moderator width, poison plate location and moderator material. The formation of an equilibrium state at low neutron energy is also discussed.