Thin-foil reflection gratings for Constellation-X

Ralf K. Heilmann, Mireille Akilian, Chih Hao Chang, Craig R. Forest, Chulmin Joo, Andrew Lapsa, Juan C. Montoya, Mark L. Schattenburg

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)


The Reflection Grating Spectrometer (RGS) on Constellation-X is designed to supply astronomers with high spectral resolution in the soft x-ray band from 0.25 to 2 keV. High resolution, large collecting area and low mass at grazing incidence require very flat and thin grating substrates, or thin-foil optics. Thin foils typically have a diameter-to-thickness ratio of 200 or higher and as a result very low stiffness. This poses a number of technological challenges in the areas of shaping, handling, positioning, and mounting of such optics. The most minute forces (gravity sag, friction, thermal mismatch with optic mount, etc.) can lead to intolerable deformations and limit figure metrology repeatability. We present results of our efforts in the manipulation and metrology of suitable grating substrates, utilizing a novel low-stress foil holder with friction-reducing flexures. A large number of reflection gratings is needed to achieve the required collecting area. We have employed nanoimprint lithography (NIL) - which uses imprint films as thin as 100 nm or less - for the high-fidelity and low-stress replication from 100 mm diameter saw-tooth grating masters.

Original languageEnglish
Pages (from-to)283-290
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Issue numberPART 1
Publication statusPublished - 2004
EventUV and Gamma-Ray Space Telescope Systems - Glasgow, United Kingdom
Duration: 2004 Jun 212004 Jun 24

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Thin-foil reflection gratings for Constellation-X'. Together they form a unique fingerprint.

Cite this