Design of an ultra-compact imaging chamber and radiation beamstop for a neutron radiography system employing particle transport

•The UUTR neutron radiography capability is computationally examined regarding the design of tri-layered neutron beamstop prototype intended to be utilized for both imaging and shielding purposes.•Augmentations are used to increase computational efficiency in MCNP6 simulations for deeply-penetrating shielding problems by employing adjoint-SN computed weight windows following the CADIS method.•Neutron responses in tally regions of importance within the beamstop design between CADIS-MCNP6 and PENTRAN are in good agreement and differ by less than 8%.