@inproceedings{a513fff4b71748668685d99e1737a642,
title = "Lateral shift mapping metrology for X-ray telescope mirrors",
abstract = "Currently, high-resolution X-ray telescope mirrors, such as for the Lynx X-Ray Observatory concept, are measured using a Fizeau interferometer with a cylindrical null corrector. Uncertainties in the null wavefront directly couple into the surface measurement uncertainty, including the axial figure and cone angle variation. We extend the absolute surface metrology method of lateral shift mapping for measuring X-ray telescope mirror segments. Lateral shift mapping involves laterally shifting the surface under test relative to the null to multiple positions. The null wavefront can be extracted from the difference between these shifted measurements, leaving only the surface under test. Accurately extracting quadratic terms of the surface under test requires measuring its tilt during shifting. We will show surface metrology results of optical flats measured by Fizeau-based lateral shift mapping with the required angle measured using an autocollimator and compare these results against a three-flat test. We will show how we plan to extend this method to conical X-ray telescope mirror metrology. The lateral shift mapping method reduces the uncertainty introduced by the cylindrical null, a critical step toward making high-resolution X-ray telescope mirrors.",
keywords = "Absolute metrology, Lynx, Metrology, X-ray mirror metrology, X-ray telescope",
author = "Wisniewski, {Hayden J.} and Whalen, {Mallory M.} and Heilmann, {Ralf K.} and Schattenburg, {Mark L.} and Chalifoux, {Brandon D.}",
note = "Funding Information: We would like to thank Will Zhang at NASA Goddard Space Flight Center and David Windt at RXO for engaging conversations while developing this method. We want to thank Heng Zuo at MIT for giving us access to the translation stage used. This work was funded by NASA grant 80NSSC20K0907. Publisher Copyright: {\textcopyright} 2021 SPIE.; Optics for EUV, X-Ray, and Gamma-Ray Astronomy X 2021 ; Conference date: 01-08-2021 Through 05-08-2021",
year = "2021",
doi = "10.1117/12.2594275",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "O'Dell, {Stephen L.} and Gaskin, {Jessica A.} and Giovanni Pareschi",
booktitle = "Optics for EUV, X-Ray, and Gamma-Ray Astronomy X",
}