Metrology of IXO mirror segments

For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

[1]  William W. Zhang,et al.  Optical metrology for the segmented optics on the Constellation-X spectroscopy x-ray telescope , 2004, SPIE Astronomical Telescopes + Instrumentation.

[2]  William A. Podgorski,et al.  Advances in the active alignment system for the IXO optics , 2010, Astronomical Telescopes + Instrumentation.

[3]  Michael Kuchel.  Interferometric measurement of rotationally symmetric aspheric surfaces , 2007 .

[4]  Guangjun Gao,et al.  Computer-generated hologram cavity interferometry test for large x-ray mirror mandrels: design , 2009 .

[5]  Paolo Conconi,et al.  3D characterization of thin glass x-ray mirrors via optical profilometry , 2010, Optical Engineering + Applications.

[6]  W. W. Zhang,et al.  Progress toward a complete metrology set for the International X-ray Observatory (IXO) soft x-ray mirrors , 2009, Optical Engineering + Applications.

[7]  Kai-Wing Chan,et al.  An approach for alignment, mounting, and integration of IXO mirror segments , 2009, Optical Engineering + Applications.

[8]  Finn Erland Christensen,et al.  Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics , 2000 .

[9]  Kai-Wing Chan,et al.  Mounting and alignment of IXO mirror segments , 2010, Astronomical Telescopes + Instrumentation.

[10]  T. Hadjimichael,et al.  An alignment procedure for multi-element precision cylinder lenses and modular enclosure to house them , 2009, Optical Engineering + Applications.

[11]  Mikhail V. Gubarev,et al.  Incoming metrology of segmented x-ray mandrels at MSFC , 2004, SPIE Astronomical Telescopes + Instrumentation.

[12]  William W. Zhang,et al.  Wavefront sensing of x-ray telescopes , 2010, Astronomical Telescopes + Instrumentation.