Wolter Mirrors for Neutron Imaging

Publication date: 2017 Source:Physics Procedia, Volume 88 Author(s): Huarui Wu, Boris Khaykovich, Xuewu Wang, Daniel S. Hussey Conventional radiography based on attenuation of a well-collimated beam remains the mainstay of neutron imaging. The spatial resolution attained with this pinhole-camera method depends on the beam collimation; therefore, achieving the spatial resolution of a few microns is practically difficult, since collimating the neutron beam results in a low flux. The use of focusing devices allows maintaining sufficient spatial resolution without collimating the beam. Therefore, axisymmetric grazing-incidence focusing mirrors (Wolter mirrors) have begun to be introduced to neutron imaging. In this paper, a design of a neutron microscope for NIST Center for Neutron Research (NCNR) is presented. We evaluate the spatial resolution and study field curvature aberrations of Wolter mirrors through ray-tracing simulations. A general formula is found describing the field curvature, and ways to counter these aberrations are discussed.

Source: Physics Procedia - June 24, 2017 Category: Physics Source Type: research