MCNP Calculation of Shielding Performance for W-Cu Shadow Shield

Calculation and analysis of the shielding performance were carried out by MCNP program for shadow shield. The results show that the neutron scattering background causing by shadow shield is less than 1.4%. The gamma-ray leakage rate emitted from shadow shield with neutron is between 10^-6~10^-14, and its disturbance to measurements of neutron scattering differential cross section can be ignored. The designed configuration obeys the shadow shielding criteria, and in the range of 4～10 m flight-path, the direct fluence from the primary neutron source is attenuated by the shadow shield to a factor of 10^-7, and the shielding effect is obvious.