Imaging hydrogenous materials with a neutron microscope

Abstract

Magnified images of materials containing hydrogen, for which the main contrast mechanism for neutrons is incoherent scattering, have been obtained using a microscope employing a neutron compound refractive lens (CRL). The CRL was composed of 100 MgF2 biconcave lenses that produced magnified (22.5×) images of polyethylene and polypropylene (hydrogen-rich) grids and biological specimens using 8.5Å cold neutrons with a 10% bandwidth. For hydrogenous materials, 98%–99% of the attenuation is by incoherent scattering and 1%–2% from neutron absorption by the hydrogen nuclei. The small angle of acceptance of the CRL discriminates against scattered neutrons from the hydrogenous object, thereby producing the needed contrast for imaging.