Design of Neutron Microscopes Equipped with Wolter-Mirror Condenser and Objective Optics for High-Fidelity Imaging and Beam Transport
Daniel S. Hussey, B. Khaykovich
We present and compare designs of three types of neutron microscopes for high-resolution neutron imaging. Like optical microscopes, our neutron microscopes have both condenser and image-forming objective optics. The optics are based on glancing-incidence axisymmetric mirrors. The microscopes are designed to provide magnification of 10 to achieve a spatial resolution of better than 10 mm. Neutrons are focused on the sample by the condenser, while the objective focuses transmitted neutrons at the detector. Important for imaging applications, the resolution of the microscope is determined by the mirrors rather than by the beam collimation as in conventional pinhole imaging, leading to possible dramatic improvements in the signal rate and resolution. Also, in contrast to pinhole imaging, in the microscope, the samples are placed far from the detector to allow for bulky sample environment without sacrificing spatial resolution. The condenser optic is designed to maximize the neutron flux and to obtain the desired beam divergence at the sample. The condenser consists of axisymmetric, confocal, paraboloid and hyperboloid mirrors, which are concentrically nested. The image- forming mirrors are designed using axisymmetric confocal ellipsoid and hyperboloid sections, so called Wolter optics of type-I, II, and III. We conclude that Wolter type-I optics provides the best performance in terms of both the signal rate and resolution.
and Khaykovich, B.
Design of Neutron Microscopes Equipped with Wolter-Mirror Condenser and Objective Optics for High-Fidelity Imaging and Beam Transport, Journal of Imaging, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930464
(Accessed August 3, 2021)