Improved Radiography and 3D Tomography Due to Better Beam Geometry

Abstract Many facilities use a neutron guide for radiography. As the beam is usually only a few centimeters wide, samples and detector are scanned across the beam to illuminate the whole detector area. The beam divergence on a neutron guide depends on the neutron wavelength, and the effective divergence depends on the transmitted spectrum. This paper gives examples of the effect of different spectra on the resolution of real-life measurements and shows a way to achieve better images on a neutron guide.