Prototyping iridium coated mirrors for X-ray astronomy
- X-ray astronomy uses space-based telescopes to overcome the disturbing absorption of the Earth´s atmosphere. The telescope mirrors are operating at grazing incidence angles and are coated with thin metal films of high-Z materials to get sufficient reflectivity for the high-energy radiation to be observed. In addition the optical payload needs to be light-weighted for launcher mass constrains. Within the project JEUMICO, an acronym for “Joint European Mirror Competence”, the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague started a collaboration to develop mirrors for X-ray telescopes. The X-ray telescopes currently developed within this Bavarian- Czech project are of Lobster eye type optical design. Corresponding mirror segments use substrates of flat silicon wafers which are coated with thin iridium films, as this material is promising high reflectivity in the X-ray range of interest. The deposition of the iridium films is based on a magnetron sputtering process. Sputtering with different parameters, especially by variation of the argon gas pressure, leads to iridium films with different properties. In addition to investigations of the uncoated mirror substrates the achieved surface roughness has been studied. Occasional delamination of the iridium films due to high stress levels is prevented by chromium sublayers. Thereby the sputtering parameters are optimized in the context of the expected reflectivity of the coated X-ray mirrors. In near future measurements of the assembled mirror modules optical performances are planned at an X-ray test facility.
Author: | Thorsten DöhringORCiD, Anne-Catherine Probst, Manfred StollenwerkORCiD, Florian Emmerich, Veronika Stehlíková, Adolf Inneman |
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DOI: | https://doi.org/10.1117/12.2265931 |
Parent Title (English): | Proceedings of the International Society for Optics and Photonics |
Publisher: | SPIE International Society for Optics and Photonics |
Place of publication: | Bellingham WA |
Editor: | René Hudec, Ladislav Pina |
Document Type: | Conference Proceeding |
Language: | English |
Year of Completion: | 2017 |
Date of first Publication: | 2017/05/31 |
Creating Corporation: | Hochschule Aschaffenburg |
Contributing Corporation: | Czech Technical University in Prague |
Release Date: | 2017/06/06 |
Tag: | Lobster Eye; X-ray; iridium; lightweight optic; mirror |
GND Keyword: | Iridium; Röntgenastronomie; Spiegelteleskop |
Volume: | 2017 |
Issue: | 10235 |
Page Number: | 8 |
First Page: | 1023504-1 |
Last Page: | 1023504-8 |
Urheberrecht: | 0 |
research focus : | Materials / Innovative Material Processing |
Materials / Material Testing & Sensor Technology | |
Licence (German): | Keine Lizenz - es gilt das deutsche Urheberrecht |