TY - CHAP A1 - Döhring, Thorsten A1 - Probst, Anne-Catherine A1 - Stollenwerk, Manfred A1 - Wen, Mingwu A1 - Proserpio, Laura ED - den Herder, Jan-Willem A. ED - Takahashi, Tadayuki ED - Bautz, Marshall T1 - Development of low-stress Iridium coatings for astronomical x-ray mirrors T2 - Proceedings of SPIE 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray N2 - Previously used mirror technologies are not suitable for the challenging needs of future X-ray telescopes. This is why the required high precision mirror manufacturing triggers new technical developments around the world. Some aspects of X-ray mirrors production are studied within the interdisciplinary project INTRAAST, a German acronym for "industry transfer of astronomical mirror technologies". The project is embedded in a cooperation of Aschaffenburg University of Applied Sciences and the Max-Planck-Institute for extraterrestrial Physics. One important task is the development of low-stress Iridium coatings for X-ray mirrors based on slumped thin glass substrates. The surface figure of the glass substrates is measured before and after the coating process by optical methods. Correlating the surface shape deformation to the parameters of coating deposition, here especially to the Argon sputtering pressure, allows for an optimization of the process. The sputtering parameters also have an influence on the coating layer density and on the micro-roughness of the coatings, influencing their X-ray reflection properties. Unfortunately the optimum coating process parameters seem to be contrarious: low Argon pressure resulted in better micro-roughness and higher density, whereas higher pressure leads to lower coating stress. Therefore additional measures like intermediate coating layers and temperature treatment will be considered for further optimization. The technical approach for the low-stress Iridium coating development, the experimental equipment, and the obtained first experimental results are presented within this paper. KW - telescope KW - mirror KW - coating KW - iridium KW - astronomy KW - Röntgenspiegel KW - Iridium KW - Beschichtung Y1 - 2016 U6 - https://doi.org/10.1117/12.2232074 VL - 2016 IS - 9905 SP - 99056S-1 EP - 99056S-7 ER - TY - CHAP A1 - Döhring, Thorsten A1 - Stollenwerk, Manfred A1 - Proserpio, Laura A1 - Breunig, Elias A1 - Friedrich, Peter T1 - The challenging development of lightweight glass mirrors for future X-ray telescopes T2 - DGaO Proceedings N2 - Previously used mirror technologies are not able to fulfill the challenging requirements of future X-ray telescopes. A promising new technology under development is the hot slumping of thin glasses. Challenges, design trades and first results are presented, including the thermal shaping process, the development of low stress coatings and the mirror segments integration concept. KW - astronomy KW - telescope KW - mirror KW - X-ray KW - glass KW - Röntgenteleskop KW - Röntgenspiegel Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?nbn:de:0287-2016-B018-0 SN - 1614-8436 VL - 2016 PB - Deutsche Gesellschaft für angewandte Optik CY - Erlangen ER - TY - CHAP A1 - Probst, Anne-Catherine A1 - Döhring, Thorsten A1 - Salmaso, Bianca A1 - Proserpio, Laura T1 - Shape measurement of thin glass substrates for X-ray mirrors: cross calibration of different equipments T2 - Proceedings of European Optical Society Annual Meeting 2016 N2 - To predict the angular resolution of future X-ray telescopes combined from thermally formed thin glass mirror segments, submicron accuracy is required on the shape measurements of the individual mirror substrates. A dedicated cross-calibration campaign using instruments of different European research institutions is presented. KW - X-ray KW - mirror KW - calibration KW - glass KW - Röntgenspiegel KW - Kalibrieren Y1 - 2016 VL - 2016 PB - European Optical Society ER - TY - CHAP A1 - Probst, Anne-Catherine A1 - Döhring, Thorsten A1 - Stollenwerk, Manfred A1 - Mingwu, Wen A1 - Proserpio, Laura ED - Cugny, Bruno ED - Karafolas, Nikos ED - Sodnik, Zoran T1 - Iridium coatings for space based x-ray optics T2 - Proceedings of SPIE N2 - Future investigations of astronomical X-ray sources require light weight telescope systems with large collecting areas and good angular resolution. The Wolter I type telescope design offers a suitable possibility for obtaining performant X-ray mirrors with high collecting areas. The technology based on replicated slumped glass optics using thin glasses thereby provides the opportunity to fulfil the light weight and mass production requirements. In NASA's telescope NuSTAR this technology has been proven as advantageous compared to previous systems. Coating thin glasses with iridium, gold or platinum enhances the reflectivity of X-ray mirrors. KW - Iridium KW - coating KW - X-ray KW - astronomy KW - mirror KW - Iridium KW - Spiegelteleskop KW - Röntgenastronomie Y1 - 2017 U6 - https://doi.org/10.1117/12.2296167 VL - 2017 IS - 10562 SP - 105621E-01 EP - 105621E-09 ER - TY - CHAP A1 - Probst, Anne-Catherine A1 - Döhring, Thorsten A1 - Zeising, Sebastian A1 - Salmaso, Bianca A1 - Stollenwerk, Manfred A1 - Proserpio, Laura T1 - Challenges in metrology of mirror segments for X-ray telescopes T2 - Proceedings of the 8th High Level Expert Meeting Asphere Metrology N2 - High angular resolution, large collecting area and reduced weight per unit area are required for astronomical X-ray telescopes of the next generation observatories. New technologies for processing X-ray mirrors are under development to fulfill these needs. One option is to realize a Wolter I type telescope constituted of several hundred nested thin and light-weight X-ray mirror segments. The individual mirror segments need to be coated with an about 100 nm thick film of a high-reflective material to enhance the reflectivity for X-rays. Thereby an accurate shape metrology of the segments is necessary to predict the angular resolution of the astronomical telescope as well as to control the development process of X-ray mirrors. We present the challenges in shape measurements of thin glasses used to control the coating process and first experimental results about the repeatability of the measurements. KW - metrology KW - mirror KW - telescope KW - Spiegelteleskop Y1 - 2017 UR - http://www.upob.de/index.php?option=com_phocadownload&view=category&download=198:8th-high-level-expert-meeting-2017-detailed-programme&id=21:upob-high-level-expert-meetings&Itemid=70 VL - 2017 IS - 8 PB - UTOB e.V. CY - Braunschweig ER -