Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

摘要

Neutron spectrum and scattered neutrons caused distortions are major problemsin fast neutron radiography and should be considered for improving the imagequality. This paper puts emphasis on the removal of these image distortions anddeviations for fast neutron radiography performed at the NECTAR facility of theresearch reactor FRM-II in Technische Universit\"at M\"unchen (TUM), Germany.The NECTAR energy spectrum is analyzed and established to modify the influencecaused by neutron spectrum, as well as the Point Scattered Function (PScF)simulated by the Monte-Carlo program MCNPX is used to evaluate scatteringeffects from the object and improve images qualities. Good analysis resultsprove the sounded effects of above two corrections.