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### Proceedings Paper

Monocrystalline silicon and the meta-shell approach to building x-ray astronomical optics
Author(s): William W. Zhang; Kim D. Allgood; Michael P. Biskach; Kai-Wing Chan; Michal Hlinka; John D. Kearney; James R. Mazzarella; Ryan S. McClelland; Ai Numata; Lawrence G. Olsen; Raul E. Riveros; Timo T. Saha; Peter M. Solly
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Paper Abstract

Angular resolution and photon-collecting area are the two most important factors that determine the power of an X-ray astronomical telescope. The grazing incidence nature of X-ray optics means that even a modest photon-collecting area requires an extraordinarily large mirror area. This requirement for a large mirror area is compounded by the fact that X-ray telescopes must be launched into, and operated in, outer space, which means that the mirror must be both lightweight and thin. Meanwhile the production and integration cost of a large mirror area determines the economical feasibility of a telescope. In this paper we report on a technology development program whose objective is to meet this three-fold requirement of making astronomical X-ray optics: (1) angular resolution, (2) photon-collecting area, and (3) production cost. This technology is based on precision polishing of monocrystalline silicon for making a large number of mirror segments and on the metashell approach to integrate these mirror segments into a mirror assembly. The meta-shell approach takes advantage of the axial or rotational symmetry of an X-ray telescope to align and bond a large number of small, lightweight mirrors into a large mirror assembly. The most important features of this technology include: (1) potential to achieve the highest possible angular resolution dictated by optical design and diffraction; and (2) capable of implementing every conceivable optical design, such as Wolter-I, WolterSchwarzschild, as well as other variations to one or another aspect of a telescope. The simplicity and modular nature of the process makes it highly amenable to mass production, thereby making it possible to produce very large X-ray telescopes in a reasonable amount of time and at a reasonable cost. As of June 2017, the basic validity of this approach has been demonstrated by finite element analysis of its structural, thermal, and gravity release characteristics, and by the fabrication, alignment, bonding, and X-ray testing of mirror modules. Continued work in the coming years will raise the technical readiness of this technology for use by SMEX, MIDEX, Probe, as well as major flagship missions.

Paper Details

Date Published: 29 August 2017
PDF: 9 pages
Proc. SPIE 10399, Optics for EUV, X-Ray, and Gamma-Ray Astronomy VIII, 103990S (29 August 2017); doi: 10.1117/12.2270861
Show Author Affiliations
William W. Zhang, NASA Goddard Space Flight Ctr. (United States)
Kim D. Allgood, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
Michael P. Biskach, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
Kai-Wing Chan, NASA Goddard Space Flight Ctr. (United States)
Univ. of Maryland, Baltimore County (United States)
Michal Hlinka, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
John D. Kearney, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
James R. Mazzarella, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
Ryan S. McClelland, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
Ai Numata, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)
Lawrence G. Olsen, NASA Goddard Space Flight Ctr. (United States)
Raul E. Riveros, NASA Goddard Space Flight Ctr. (United States)
Univ. of Maryland, Baltimore County (United States)
Timo T. Saha, NASA Goddard Space Flight Ctr. (United States)
Peter M. Solly, NASA Goddard Space Flight Ctr. (United States)
Stinger Ghaffarian Technologies, Inc. (United States)

Published in SPIE Proceedings Vol. 10399:
Optics for EUV, X-Ray, and Gamma-Ray Astronomy VIII
Stephen L. O'Dell; Giovanni Pareschi, Editor(s)