Nuclear Technology / Volume 168 / Number 3 / December 2009 / Pages 768-772
MC Calculations / Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (PART 3) / Radiation Protection / dx.doi.org/10.13182/NT09-A9304
Reflection of thermal and cold neutrons by polished surfaces and so-called supermirrors effect radiation fields in and around neutron beamlines. To allow the prediction of these radiation fields with MCNPX 2.5.0, two new input cards were implemented for defining mirror properties of surfaces. Mirror properties can be linked to any type of surface, in contrast to other neutron optics codes, where the mirror properties are part of component descriptions, allowing the simulation of very complex neutron optical devices. First calculations are under way to verify the new capability against combinations of MCNPX and MCSTAS (neutron optics code) simulations. Also, simulations are under way to compare the predicted neutron beam characteristics against measurements conducted at Paul Scherrer Institut.