@inproceedings{DoehringStollenwerkGongetal.2015, author = {D{\"o}hring, Thorsten and Stollenwerk, Manfred and Gong, Qingqing and Proserpio, Laura and Winter, Anita and Friedrich, Peter}, title = {The challenge of developing thin mirror shells for future X-ray telescopes}, series = {Proceedings of SPIE}, volume = {2015}, booktitle = {Proceedings of SPIE}, number = {9628}, organization = {Hochschule Aschaffenburg}, pages = {962809-1 -- 962809-8}, year = {2015}, abstract = {Previously used mirror technologies are not able to fulfil the requirements of future X-ray telescopes due to challenging requests from the scientific community. Consequently new technical approaches for X-ray mirror production are under development. In Europe the technical baseline for the planned X-ray observatory ATHENA is the radical new approach of silicon pore optics. NASA´s recently launched NuSTAR mission uses segmented mirrors shells made from thin bended glasses, successfully demonstrating the feasibility of the glass forming technology for X-ray mirrors. For risk mitigation also in Europe the hot slumping of thin glasses is being developed as an alternative technology for lightweight X-ray telescopes. The high precision mirror manufacturing requires challenging technical developments; several design trades and trend-setting decisions need to be made and are discussed within this paper. Some new technical and economic aspects of the intended glass mirror serial production are also studied within the recently started interdisciplinary project INTRAAST, an acronym for "industry transfer of astronomical mirror technologies". The goal of the project, embedded in a cooperation of the Max-Planck-Institute for extraterrestrial Physics and the University of Applied Sciences Aschaffenburg, is to master the challenge of producing thin mirror shells for future X-ray telescopes. As a first project task the development of low stress coatings for thin glass mirror substrates have been started, the corresponding technical approach and first results are presented.}, subject = {Astronomie}, language = {en} } @inproceedings{WinterBreunigFriedrichetal.2015, author = {Winter, Anita and Breunig, Elias and Friedrich, Peter and Proserpio, Laura and D{\"o}hring, Thorsten}, title = {Indirect glass slumping for future X-ray missions: overview, status and progress}, series = {Proceedings of SPIE}, volume = {2015}, booktitle = {Proceedings of SPIE}, number = {9603}, organization = {Max-Planck-Institut f{\"u}r extraterrestrische Physik}, pages = {960308-1 -- 960308-8}, year = {2015}, abstract = {Future X-ray telescopes aim for large effective area within the given mass limits of the launcher. A promising method is the hot shaping of thin glass sheets via a thermal slumping process. This paper presents the status and progress of the indirect glass slumping technology developed at the Max-Planck-Institut for extraterrestrial Physics (MPE). Recent developments in our research include the use of the mould material Cesic under vacuum, as well as the fabrication of a high-precision slumping mould, which meets the requirements of large, high angular resolution missions like ATHENA. We describe the way forward to optimise the slumping process on these materials, the force-free integration concept and its progress, as well as the first test on reflective coating application.}, subject = {Astronomie}, language = {en} } @misc{SpeitDoehringWolff2014, author = {Speit, Burkard and D{\"o}hring, Thorsten and Wolff, Silke}, title = {Lead-containing space glass, its production and use}, year = {2014}, abstract = {The optical glasses have increased refractive indices and are useful for making space-saving and light-weight imaging optics with lenses of different glass types for use in different objects travelling in space. The optical glasses are suitable for production of optics having low total weight, which is decisive for space applications. These space glasses have high UV- and VIS-transmittance in a range of between 300 and 800 nm and high stability of transmittance over a period of years, because their aging has been greatly limited.}, subject = {Optisches Glas}, language = {en} } @misc{SpeitDoehringWolff2013, author = {Speit, Burkard and D{\"o}hring, Thorsten and Wolff, Silke}, title = {Lead-containing space glass, its production and use}, year = {2013}, abstract = {The space glass has a composition, in wt. \% based on oxide content, of: SiO2, 5-65; B2O3, 0-40; Al2O3, 0-12; PbO, 25-50; Na2O 0-8; K2O, 0-20; Sigma alkali metal oxides, at least 0.25; and at least 0.1 wt. \% of a total amount of three or more doping agents selected from CeO2, MoO3, Bi2O3, WO3, Ag2O, SnO2, Sb2O3 and As2O3. In addition, it contains one or more of the following doping agents in the following amounts: at most 1 wt. \%, CeO2; at most 0.02 wt. \%, As2O3; at most 0.3 wt. \%, Sb2O3; and at most 0.5 wt. \%, SnO2. Light-weight optical systems for space are made from it, because of its high radiation resistance. A preferred process for making space glass includes melting the oxide starting ingredients at 1050 DEG C. to 1200 DEG C. to form a melt and refining the melt at 1230 DEG C. to 1350 DEG C.}, subject = {Optisches Glas}, language = {en} } @misc{SpeitWolffDoehring2014, author = {Speit, Burkard and Wolff, Silke and D{\"o}hring, Thorsten}, title = {Verre spatial contenant du plomb, ses production et utilisation}, year = {2014}, abstract = {The optical glasses have increased refractive indices and are useful for making space-saving and light-weight imaging optics with lenses of different glass types for use in different objects travelling in space. The optical glasses are suitable for production of optics having low total weight, which is decisive for space applications. These space glasses have high UV- and VIS-transmittance in a range of between 300 and 800 nm and high stability of transmittance over a period of years, because their aging has been greatly limited.}, subject = {Optisches Glas}, language = {fr} } @misc{SpeitWolffDoehring2014, author = {Speit, Burkard and Wolff, Silke and D{\"o}hring, Thorsten}, title = {Lead-containing space glass, its production and use}, year = {2014}, abstract = {The space glasses have a composition, in wt. \% based on oxide content, including SiO2, 12-45; B2O3, 0-4; Al2O3, 0-4; TiO2, 0-5; PbO, 50-82; Na2O, 0-4; K2O, 0-8; and at least 0.1 wt. \% of a total amount of at least three doping agents selected from CeO2, MoO3, Bi2O3, WO3, Ag2O, SnO2, Sb2O3 and As2O3. Light-weight and space-saving optical systems for outer space applications can be made with these space glasses, which have high UV- and VIS-transmittance and high transmittance stability, because of their high radiation resistance based on their dopant content. A preferred process for making the space glass includes melting the above-stated oxide ingredients in a quartz crucible at 1050 DEG C. to 1200 DEG C. to form a melt and refining the melt at 1230 DEG C. to 1350 DEG C.}, subject = {Optisches Glas}, language = {en} } @misc{DoehringMitra2012, author = {D{\"o}hring, Thorsten and Mitra, Ina}, title = {OPTICAL COMPONENT}, year = {2012}, abstract = {To provide an optically uniform quality component which is a large size optical transparency component such as a lenz, prism, mirror or the like. ;SOLUTION: The optical component comprises an optical glass which comprises 35 to 70 wt.\% SiO2, 17 to 35 wt.\% Al2O3, 3 to 17 wt.\% P2O5, 0 to 6 wt.\% Li2O, 0.5 to 4 wt.\% MgO, 0.5 to 3 wt.\% ZnO, a maximum of 1 wt.\% CaO, a maximum of 0.5 wt.\% BaO, 0.5 to 6 wt.\% TiO2, 0.5 to 3 wt.\% ZrO2, 0 to 1 wt.\% Na2O, 0 to 1 wt.\% K2O, a maximum of 2 wt.\% of refining agents, and a maximum of 1 wt.\% of a coloring oxide and other impurities, and has at least 50 mm maximum thickness.}, subject = {Optisches Glas}, language = {en} } @misc{SchaeferDoehringSeibertetal.2013, author = {Sch{\"a}fer, Martin and D{\"o}hring, Thorsten and Seibert, Volker and Westerhoff, Thomas and Nowak, Hans-Joachim}, title = {SUBSTRATE FOR MIRROR SUPPORT WITH REDUCED WEIGHT AND MIRROR PROVIDED WITH MIRROR SUPPORT WITH REDUCED WEIGHT}, year = {2013}, abstract = {To provide a substrate for a mirror support, in which there still remains a high rigidity, despite a reduced weight. ;SOLUTION: In a substrate, particularly in a substrate for a mirror support, in which recesses are introduced in one surface, preferably in the back side of the substrate, as a result of which, in particular, bridging pieces are defined between the recesses, in order to achieve the situation in which despite a reduced weight, a high rigidity still remains, which means only a slight sagging after the correct take-in of the substrate in a holding device provided for it, at least one first position of the bridging pieces includes a width that is different from a second portion of the bridging pieces.}, subject = {Spiegeloptik}, language = {en} } @misc{SchaeferDoehringSeibertetal.2014, author = {Sch{\"a}fer, Martin and D{\"o}hring, Thorsten and Seibert, Volker and Westerhoff, Thomas and Nowak, Hans-Joachim}, title = {Substrate for a mirror support with reduced weight as well as mirror with reduced-weight mirror support}, year = {2014}, abstract = {Diesen Text {\"u}bersetzen Erste Seite Clipping von US8911098 (B2) In a substrate, particularly in a substrate for a mirror support, in which recesses are introduced in one surface, preferably in the back side of the substrate, as a result of which, in particular, bridging pieces are defined between the recesses, in order to achieve the situation that despite a reduced weight, a high rigidity still remains, which means only a slight sagging after its correct uptake in a holding device provided for it, it is provided that at least one first portion of the bridging pieces has a width that is different than a second portion of the bridging pieces.}, subject = {Spiegeloptik}, language = {en} } @misc{SchaeferDoehringSeibertetal.2015, author = {Sch{\"a}fer, Martin and D{\"o}hring, Thorsten and Seibert, Volker and Westerhoff, Thomas and Nowak, Hans-Joachim}, title = {Mirror supporting substratum for e.g. terrestrial observation, has spacers defined between one set of recesses and/ or two set of recesses, where part of one set of spacers has width different from width of part of other set of spacers}, year = {2015}, abstract = {The substratum (1) has two set of recesses (2, 3, 4, 7, 8) formed in a rear face (16), where the substratum is produced from a monolithic block of material including a lithium- aluminum- silicon type glass ceramic material. Set of spacers (5, 6, 9, 10) are defined between one set of recesses (2, 3, 4) and/ or the two set of recesses. A part of one set of spacers (5, 6) defined by the former recesses has width different from width of a part of other set of spacers (9, 10) defined by the latter recesses.}, subject = {Spiegeloptik}, language = {en} } @misc{SpeitWolffDoehring2015, author = {Speit, Burkard and Wolff, Silke and D{\"o}hring, Thorsten}, title = {Lead-containing space glass, its production and its use}, year = {2015}, abstract = {The invention relates to a lead-containing space glass, its production and its use. The optical glasses have increased refractive indices and are useful for making space-saving and light-weight imaging optics with lenses of different glass types for use in different objects travelling in space. The optical glasses are suitable for production of optics having low total weight, which is decisive for space applications. These space glasses have high UV- and VIS-transmittance in a range of between 300 and 800 nm and high stability of transmittance over a period of years, because their aging has been greatly limited.}, subject = {Optisches Glas}, language = {en} } @misc{SpeitWolffDoehring2015, author = {Speit, Burkard and Wolff, Silke and D{\"o}hring, Thorsten}, title = {Lead-containing space glass, its production and use}, year = {2015}, abstract = {The invention relates to a lead-containing space glass, its production and use. The optical glasses have increased refractive indices and are useful for making space-saving and light-weight imaging optics with lenses of different glass types for use in different objects travelling in space. The optical glasses are suitable for production of optics having low total weight, which is decisive for space applications. These space glasses have high UV- and VIS-transmittance in a range of between 300 and 800 nm and high stability of transmittance over a period of years, because their aging has been greatly limited.}, subject = {Optisches Glas}, language = {en} } @inproceedings{DoehringProbstStollenwerketal.2016, author = {D{\"o}hring, Thorsten and Probst, Anne-Catherine and Stollenwerk, Manfred and Wen, Mingwu and Proserpio, Laura}, title = {Development of low-stress Iridium coatings for astronomical x-ray mirrors}, series = {Proceedings of SPIE 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray}, volume = {2016}, booktitle = {Proceedings of SPIE 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray}, number = {9905}, editor = {den Herder, Jan-Willem A. and Takahashi, Tadayuki and Bautz, Marshall}, doi = {10.1117/12.2232074}, pages = {99056S-1 -- 99056S-7}, year = {2016}, abstract = {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.}, subject = {R{\"o}ntgenspiegel}, language = {en} } @inproceedings{LechnerDoehring2016, author = {Lechner, Kevin and D{\"o}hring, Thorsten}, title = {Market study on the enabling technology of computer generated holograms}, series = {DGaO Proceedings}, volume = {2016}, booktitle = {DGaO Proceedings}, organization = {Deutsche Gesellschaft f{\"u}r angewandte Optik}, issn = {1614-8436}, url = {http://nbn-resolving.de/nbn:de:0287-2016-P009-4}, pages = {2}, year = {2016}, abstract = {Computer generated holograms (CGHs) are used in interferometric testing to enable the high-quality production of non-spherical optical elements. Today the CGH production is mastered by a few manufacturers only. To provide CGH users with an overview on the corresponding market, this market study was raised. A table of commercial and institutional CGH suppliers has been created.}, subject = {Synthetisches Hologramm}, language = {en} } @inproceedings{DoehringStollenwerkProserpioetal.2016, author = {D{\"o}hring, Thorsten and Stollenwerk, Manfred and Proserpio, Laura and Breunig, Elias and Friedrich, Peter}, title = {The challenging development of lightweight glass mirrors for future X-ray telescopes}, series = {DGaO Proceedings}, volume = {2016}, booktitle = {DGaO Proceedings}, publisher = {Deutsche Gesellschaft f{\"u}r angewandte Optik}, address = {Erlangen}, organization = {Hochschule Aschaffenburg}, issn = {1614-8436}, url = {http://nbn-resolving.de/nbn:de:0287-2016-B018-0}, pages = {2}, year = {2016}, abstract = {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.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{ProbstDoehringSalmasoetal.2016, author = {Probst, Anne-Catherine and D{\"o}hring, Thorsten and Salmaso, Bianca and Proserpio, Laura}, title = {Shape measurement of thin glass substrates for X-ray mirrors: cross calibration of different equipments}, series = {Proceedings of European Optical Society Annual Meeting 2016}, volume = {2016}, booktitle = {Proceedings of European Optical Society Annual Meeting 2016}, publisher = {European Optical Society}, organization = {Hochschule Aschaffenburg}, pages = {2}, year = {2016}, abstract = {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.}, subject = {R{\"o}ntgenspiegel}, language = {en} } @inproceedings{DoehringProbstZeising2018, author = {D{\"o}hring, Thorsten and Probst, Anne-Catherine and Zeising, Sebastian}, title = {Analyse der Schichtspannungen von R{\"o}ntgenspiegeln mit einem Weißlichtinterferometer}, series = {DGaO-Proceedings}, volume = {2018}, booktitle = {DGaO-Proceedings}, number = {2018}, publisher = {Deutsche Gesellschaft f{\"u}r angewandte Optik e.V.}, address = {Erlangen}, organization = {Hochschule Aschaffenburg}, issn = {1614-8436}, pages = {P10-1 -- P10-2}, year = {2018}, abstract = {An der Hochschule Aschaffenburg werden iridiumbasierte Schichtsysteme f{\"u}r r{\"o}ntgenastronomische Anwendungen hergestellt. Unter Nutzung eines Weißlichtinterferometers wurde hierf{\"u}r ein Verfahren zur Vermessung der inh{\"a}renten Schichtspannungen entwickelt. Erste vielversprechende Ergebnisse von spannungsarmen R{\"o}ntgenreflexionsbeschichtungen werden vorgestellt.}, subject = {R{\"o}ntgenspiegel}, language = {de} } @inproceedings{ProbstDoehringStollenwerketal.2017, author = {Probst, Anne-Catherine and D{\"o}hring, Thorsten and Stollenwerk, Manfred and Mingwu, Wen and Proserpio, Laura}, title = {Iridium coatings for space based x-ray optics}, series = {Proceedings of SPIE}, volume = {2017}, booktitle = {Proceedings of SPIE}, number = {10562}, editor = {Cugny, Bruno and Karafolas, Nikos and Sodnik, Zoran}, doi = {10.1117/12.2296167}, pages = {105621E-01 -- 105621E-09}, year = {2017}, abstract = {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.}, subject = {Iridium}, language = {en} } @article{DoehringHudec2018, author = {D{\"o}hring, Thorsten and Hudec, Rene}, title = {JEUMICO and TRILAMICO: Dimensions of successful Bavarian-Czech cooperation}, series = {Contributions of the Astronomical Observatory Skalnat{\´e} Pleso}, volume = {2018}, journal = {Contributions of the Astronomical Observatory Skalnat{\´e} Pleso}, number = {Vol. 48 / 3}, editor = {Skopal, August{\´i}n}, pages = {430 -- 436}, year = {2018}, abstract = {In December 2017 the two projects JEUMICO (an acronym for Joint European Mirror Cooperation) and TRILAMICO (standing for Trilateral Mirror Collaboration) are ending. Different aspects of this Bavarian-Czech collaboration between Aschaffenburg University and the Czech Technical University in Prague are discussed. The multiple dimensions of this cooperation are scientific achievements, public relation measures, internationalization of education, financial aspects, inter-cultural communication, and also the actual political situation within Europe.}, subject = {R{\"o}ntgenspiegel}, language = {en} } @article{StehlikovaProbstNentvichetal.2018, author = {Stehlikova, Veronika and Probst, Anne-Catherine and Nentvich, Ondrej and Urban, Martin and Sieger, Ladislav and D{\"o}hring, Thorsten and Hudec, Ren{\´e}}, title = {Study of multiple layers coatings for X-ray mirrors}, series = {Contributions of the Astronomical Observatory Skalnat{\´e} Pleso}, volume = {2018}, journal = {Contributions of the Astronomical Observatory Skalnat{\´e} Pleso}, number = {48}, editor = {Skopal, August{\´i}n}, pages = {488 -- 497}, year = {2018}, abstract = {This paper focuses on a theoretical background that motivated the experimental campaign of multiple layer coatings of X-ray mirrors, and the first results of the testing of the prepared samples. Simulations of the use of different overcoats were performed in order to improve the reflectivity of thin iridium coatings designed for X-ray optics effective in the energy up to 10 keV. Samples based on these simulations were prepared and are being tested for the properties that influence the X-ray optical performance, such as layer homogeneity, density and surface micro-roughness. Further the topic of the coating stress was addressed, as it is an issue in case of thin, lightweight X-ray mirrors and affects the time stability of layers. The discussion and preliminary results conclude our contribution.}, subject = {R{\"o}ntgenspiegel}, language = {en} } @article{BuettnerProbstEmmerichetal.2018, author = {B{\"u}ttner, Andre and Probst, Anne-Catherine and Emmerich, Florian and Damm, Christine and Rellinghaus, Bernd and D{\"o}hring, Thorsten and Stollenwerk, Manfred}, title = {Influence of Sputtering Pressure on the Microstructure and Layer Properties of Iridium Thin Films}, series = {Thin Solid Films}, volume = {2018}, journal = {Thin Solid Films}, number = {662}, issn = {0040-6090}, pages = {41 -- 46}, year = {2018}, abstract = {Iridium layers with low stress, high density, and low surface roughness find widespread use in different high-technology applications. This paper presents a study of the influence of the sputtering pressure on the properties of iridium thin films and of its effect on the substrate surface microstructure. We analysed the dependence of the microstructure, crystalline structure, electrical resistivity, and deposition rate on the sputtering pressure and surface defects of the substrate. For the latter, plasma etching of the substrate was performed for different processing times and its effect on the surface roughness of substrates and, subsequently, on the grown iridium films, was examined. The sputtering pressure and the substrate plasma etching time both had a strong influence on the microstructure and surface roughness. These microstructural changes are in good agreement with the tendency described in the Thornton Structure-Zone Model for different sputtering pressures and the microstructure phase map of Alvarez. The electrical resistivity, deposition rate, and crystalline structure were highly dependent on the sputtering pressure.}, subject = {Iridium}, language = {en} } @inproceedings{DoehringProbstStollenwerketal.2017, author = {D{\"o}hring, Thorsten and Probst, Anne-Catherine and Stollenwerk, Manfred and Emmerich, Florian and Stehl{\´i}kov{\´a}, Veronika and Inneman, Adolf}, title = {Prototyping iridium coated mirrors for X-ray astronomy}, series = {Proceedings of the International Society for Optics and Photonics}, volume = {2017}, booktitle = {Proceedings of the International Society for Optics and Photonics}, number = {10235}, editor = {Hudec, Ren{\´e} and Pina, Ladislav}, publisher = {SPIE International Society for Optics and Photonics}, address = {Bellingham WA}, organization = {Hochschule Aschaffenburg}, doi = {10.1117/12.2265931}, pages = {1023504-1 -- 1023504-8}, year = {2017}, abstract = {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.}, subject = {Iridium}, language = {en} } @inproceedings{StehlikovaUrbanNentvichetal.2017, author = {Stehlikova, Veronika and Urban, Martin and Nentvich, Ondrej and Inneman, Adolf and D{\"o}hring, Thorsten and Probst, Anne-Catherine}, title = {Study of lobster eye optics with iridium coated X-ray mirrors for a rocket experiment}, series = {Proceedings of the International Society for Optics and Photonics (SPIE)}, volume = {2017}, booktitle = {Proceedings of the International Society for Optics and Photonics (SPIE)}, number = {10235}, editor = {Hudec, Rene}, publisher = {SPIE International Society for Optics and Photonics}, address = {Bellingham WA}, organization = {Czech Technical University in Prague}, doi = {10.1117/12.2265769}, pages = {1023505-1 -- 1023505-7}, year = {2017}, abstract = {In the field of astronomical X-ray telescopes, different types of optics based on grazing incidence mirrors can be used. This contribution describes the special design of a lobster-eye optics in Schmidt's arrangement, which uses dual reflection to increase the collecting area. The individual mirrors of this wide-field telescope are made of at silicon wafers coated with reflecting iridium layers. This iridium coatings have some advantages compared to more common gold layers as is shown in corresponding simulations. The iridium coating process for the X-ray mirrors was developed within a cooperation of the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague. Different mirror parameters essential for a proper function of the X-ray optics, like the surface microroughness and the problematic of a good adhesion quality of the coatings were studied. After integration of the individual mirrors into the final lobster-eye optics and the corresponding space qualification testing it is planned to fly the telescope in a recently proposed NASA rocket experiment.}, subject = {Iridium}, language = {en} } @misc{SpeitWolffDoehring2017, author = {Speit, Burkard and Wolff, Silke and D{\"o}hring, Thorsten}, title = {LEAD-CONTAINING RADIATION RESISTANT GLASS AND MANUFACTURING THE SAME}, year = {2017}, abstract = {PROBLEM TO BE SOLVED: To provide a radiation resistant glass having radiation resistance and high transparency.SOLUTION: There is provided a radiation resistant glass containing, by wt.\%, the following components: SiO of 12 to 45, BO of 0 to 4, AlO of 0 to 4, TiO of 0 to 5, PbO of 50 to 82, NaO of 0 to 4, KO of 0 to 8, and at least 3 doping agents selected from a group consisting of CeO, MoO, BiO, WO, AgO, SnO, SbO and AsO where the total of these doping agents are at least at 0.1 wt.\% and the weight percentage of AsO is 0 to <0.2\%.}, subject = {Glas}, language = {mul} } @inproceedings{ProbstDoehringZeisingetal.2017, author = {Probst, Anne-Catherine and D{\"o}hring, Thorsten and Zeising, Sebastian and Salmaso, Bianca and Stollenwerk, Manfred and Proserpio, Laura}, title = {Challenges in metrology of mirror segments for X-ray telescopes}, series = {Proceedings of the 8th High Level Expert Meeting Asphere Metrology}, volume = {2017}, booktitle = {Proceedings of the 8th High Level Expert Meeting Asphere Metrology}, number = {8}, publisher = {UTOB e.V.}, address = {Braunschweig}, organization = {Hochschule Aschaffenburg}, pages = {4}, year = {2017}, abstract = {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.}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringProbstStehlikovaetal.2017, author = {D{\"o}hring, Thorsten and Probst, Anne-Catherine and Stehlikova, Veronika and Skala, Petr and Inneman, Adolf and Hudec, Rene}, title = {JEUMICO - Bayerisch-tschechische Kooperation zur Entwicklung von R{\"o}ntgenteleskopen}, series = {DGaO-Proceedings}, volume = {2017}, booktitle = {DGaO-Proceedings}, number = {2017}, publisher = {DGaO}, organization = {Hochschule Aschaffenburg}, issn = {1614-8436}, pages = {2}, year = {2017}, abstract = {Das Projekt JEUMICO wird vom Projekttr{\"a}ger BAYHOST im Rahmen eines Programms f{\"u}r bilaterale wissenschaftliche Projekte zwischen Tschechien und Bayern gef{\"o}rdert. Inhaltlich werden von der Hochschule Aschaffenburg und der Technischen Universit{\"a}t Prag hier gemeinsam R{\"o}ntgenoptiken f{\"u}r ein geplantes astronomisches Experiment an Bord einer NASA-H{\"o}henrakete entwickelt.}, subject = {R{\"o}ntgenstrahlung}, language = {de} } @inproceedings{HudecDoehringRemisova2017, author = {Hudec, Rene and D{\"o}hring, Thorsten and Remisova, Katerina}, title = {Lobster Eye Optics \& Biomimetics}, series = {DGaO-Proceedings}, volume = {2017}, booktitle = {DGaO-Proceedings}, number = {2017}, publisher = {DGaO}, organization = {Czech Academy of Sciences}, issn = {1614-8436}, pages = {2}, year = {2017}, abstract = {We present optic designs based on biomimetic, namely technical applications of animal eyes principles (here: Lobster Eyes) for the special application of wide field X-ray imaging. Thereby we show and discuss some experimental results and correlate them with simulations. Preliminary results of an ongoing study on other strange animal mirror eyes with potential scientific and technical applications are also discussed. Some of them are based on the principle of multilayer multi-mirror active optics arrangements. The Lobster Eye X-ray optics needs special reflective coatings for a better performance, which are currently developed within the Bavarian-Czech cooperation project JEUMICO.}, subject = {R{\"o}ntgenastronomie}, language = {en} } @inproceedings{SkalaDoehringHudec2017, author = {Skala, Petr and D{\"o}hring, Thorsten and Hudec, Rene}, title = {Colors of the universe - market study on optical filters for professional astronomy}, series = {DGaO-Proceedings}, volume = {2017}, booktitle = {DGaO-Proceedings}, number = {2017}, publisher = {DGaO}, organization = {Czech Technical University in Prague}, issn = {1614-8436}, pages = {2}, year = {2017}, abstract = {For astronomers, filters are essential observational tools and in many cases, it is hard for them to find the best supplier. We present list of filters manufacturers and their capabilities sorted and discussed.}, subject = {Markt{\"u}bersicht}, language = {en} } @article{HudecDoehring2017, author = {Hudec, Rene and D{\"o}hring, Thorsten}, title = {JEUMICO: Czech-Bavarian astronomical X-ray optics project}, series = {Contributions of the Astronomical Observatory Skalnat{\´e} Pleso}, volume = {2017}, journal = {Contributions of the Astronomical Observatory Skalnat{\´e} Pleso}, number = {47}, editor = {Slovak Academy of Sciences Astronomical Institute,}, pages = {170 -- 177}, year = {2017}, abstract = {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. Corresponding mirror segments use substrates of at silicon wafers which are coated with thin iridium � lms, as this material is promising high re ectivity in the X-ray range of interest. The sputtering parameters are optimized in the context of the expected re ectivity 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.}, subject = {Iridium}, language = {en} } @inproceedings{Doehring2017, author = {D{\"o}hring, Thorsten}, title = {Critical discussion on the UV absorption properties of Earth's atmosphere}, series = {Proceedings of SPIE}, volume = {2017}, booktitle = {Proceedings of SPIE}, number = {10453}, publisher = {SPIE}, organization = {Hochschule Aschaffenburg}, doi = {10.1117/12.2271645}, pages = {104530I-1 -- 104530I-10}, year = {2017}, abstract = {Sun´s ultraviolet radiation is classified into UV-A, UV-B, and UV-C bands. Thereby UV-A passes through Earth´s atmosphere, while UV-B is partially absorbed by ozone. The limitations of the commonly accepted statement, that UV-C is always completely absorbed by Earth´s atmosphere, are discussed critically. Below 200 nm the solar spectrum is strongly absorbed by molecular oxygen. The stratospheric ozone layer has strong absorption between 200 nm and 300 nm. However, the "ozone hole" increases UV-B radiation just below 300 nm and may also open a transmitting atmospheric window for harmful UV-C at the overlap region between oxygen absorption and ozone absorption.}, subject = {Ozonloch}, language = {en} } @inproceedings{DoehringProbstEmmerichetal.2017, author = {D{\"o}hring, Thorsten and Probst, Anne-Catherine and Emmerich, Florian and Stollenwerk, Manfred and Stehlikova, Veronika and Friedrich, Peter and Damm, Christine}, title = {Development of iridium coated X-ray mirrors for astronomical applications}, series = {Proceedings of the International Society for Optics and Photonics (SPIE)}, volume = {2017}, booktitle = {Proceedings of the International Society for Optics and Photonics (SPIE)}, number = {10399}, publisher = {SPIE}, doi = {10.1117/12.2273988}, pages = {103991C-1 -- 103991C-8}, year = {2017}, abstract = {Future space-based X-ray observatories need to be very lightweight for launcher mass constraints. Therefore they will use a reduced mirror thickness, which results in the additional requirement of low coating stress to avoid deformation of the initial precisely shaped mirror substrates. Due to their excellent reflection properties iridium coatings are sometimes applied for grazing incidence mirrors in astronomical X-ray telescopes. At Aschaffenburg University of Applied Sciences the coating of thin iridium films by an RF-magnetron sputtering technique is under development. The work is embedded in collaborations with the Max-Planck-Institute for Extraterrestrial Physics in Germany, the Czech Technical University in Prague, the Osservatorio Astronomico di Brera in Italy, the German Leibniz Institute for Solid State and Materials Research in Dresden, and the French Institute Fresnel. Sputtering with different parameters leads to iridium films with different properties. The current work is focused on the microstructure of the iridium coatings to study the influence of the substrate and of the argon gas pressure on the thin film growing process. Correlations between coating density, surface micro-roughness, the crystalline structure of the iridium layers, and the expected reflectivity of the X-ray mirror as well as coating stress effects are presented and discussed. The final goal of the project is to integrate the produced prototype mirrors into an X-ray telescope module. On a longer timescale measurements of the mirror modules optical performance are planned at the X-ray test facility PANTER.}, subject = {Iridium}, language = {en} } @inproceedings{StehlikovaProserpioFriedrichetal.2017, author = {Stehlikova, Veronika and Proserpio, Laura and Friedrich, Peter and Madarasz, Emanuel and Breunig, Elias and Burwitz, Vadim and D{\"o}hring, Thorsten and Probst, Anne-Catherine}, title = {Indirect glass slumping of grazing incidence mirror segments for lightweight x-ray telescopes}, series = {Proceedings of the International Society for Optics and Photonics (SPIE)}, volume = {2017}, booktitle = {Proceedings of the International Society for Optics and Photonics (SPIE)}, number = {10399}, publisher = {SPIE}, organization = {Max-Planck Institut f{\"u}r extraterrestrische Physik}, doi = {10.1117/12.2272671}, pages = {103991Z-1 -- 103991Z-7}, year = {2017}, abstract = {The paper provides a description of recent progress in the development of lightweight, precision and highthroughput grazing-incidence mirrors for X-ray astronomy made of glass. In particular, the indirect slumping technology under investigation at the Max Planck Institute for Extraterrestrial Physics (MPE) is reviewed and recent activities are presented together with the research approach. The glass slumping technique foresees several steps: a thermal forming process using a suitable mould; a re ective layer application; the alignment and integration of mirror segments into a supporting structure; and the � nal veri� cation of prototype modules using X-rays. Each step is considered at MPE, with the involvement of partner institutes and universities. The last year of activities was mainly dedicated to the procurement of new moulds and to the application of Iridium coating. The main results will be presented.}, subject = {Iridium}, language = {en} } @inproceedings{StehlikovaProbstNentvichetal.2017, author = {Stehlikova, Veronika and Probst, Anne-Catherine and Nentvich, Ondrej and Urban, Martin and Inneman, Adolf and Sieger, Ladislav and Marsikova, Veronika and D{\"o}hring, Thorsten}, title = {Development of iridium coated silicon X-ray mirrors for Lobster Eye astronomical telescopes}, series = {Proceedings of EOSMOS 2017}, volume = {2017}, booktitle = {Proceedings of EOSMOS 2017}, number = {EOSMOS 2017}, publisher = {European Optical Society}, organization = {CVUT Prag}, pages = {1 -- 2}, year = {2017}, abstract = {In the field of X-ray astronomy different types of telescope optics based on grazing incidence mirrors can be used. This contribution presents a special design of a Lobster Eye wide-field telescope with mirrors based on flat silicon wafers and the task of coating such mirror substrates with reflective iridium layers.}, subject = {Iridium}, language = {en} } @article{ProbstStollenwerkEmmerichetal.2017, author = {Probst, Anne-Catherine and Stollenwerk, Manfred and Emmerich, Florian and B{\"u}ttner, Andre and Zeising, Sebastian and Stadtm{\"u}ller, Johannes and Riethm{\"u}ller, Franziska and Stehlikova, Veronika and Mingwu, Wen and Proserpio, Laura and Damm, Christine and Rellinghaus, Bernd and D{\"o}hring, Thorsten}, title = {Influence of sputtering pressure on the nanostructure and the X-ray reflectivity of iridium coatings}, series = {Surface and Coatings Technology}, volume = {2017}, journal = {Surface and Coatings Technology}, number = {343}, issn = {0257-8972}, pages = {101 -- 107}, year = {2017}, abstract = {Reflective mirror coatings made of iridium are used in X-ray telescopes of the Chandra X-ray Observatory (CXO) launched in 1999 by the National Aeronautics and Space Administration (NASA) to investigate astronomical sources at photon energies below 10. keV. These coatings were produced in a DC magnetron sputtering process and have so far proven their suitability for space-based applications. We are considering in the present paper the processing of thin iridium films for lightweight telescopes using the radio frequency magnetron sputtering technique with an oblique angle deposition. The coating development presented here is focused on the influence of total sputtering pressure on film properties as well as on its impact on the mirror's performance. Characterisation methods such as X-ray diffractometry, X-ray reflectometry, atomic force microscopy and transmission electron microscopy have been used. Correlations between morphology, density, surface micro-roughness, crystal structure of the iridium layer and the expected reflectivity of the X-ray mirror are described and discussed.}, subject = {Iridium}, language = {en} } @misc{DoehringProbullaKomziketal.2018, author = {D{\"o}hring, Thorsten and Probulla, Theodor and Komzik, Richard and Mann, Michael and Sivanic, Peter and Stollenwerk, Manfred}, title = {Slovak-Bavarian collaboration on the development of telescope instrumentation}, editor = {Hambalek, Lubomir}, organization = {Hochschule Aschaffenburg}, pages = {1}, year = {2018}, abstract = {Within the project SLOBATCO (Slovak-Bavarian Telescope Collaboration) the Astronomical Institute of the Slovak Academy of Sciences and Aschaffenburg University of Applied Sciences collaborate in the development and commissioning of the new {\O}1.3 m astronomical telescope and the corresponding scientific instrumentation. The project is funded by the Bavarian Academic Center for Central, Eastern and Southeastern Europe (BAYHOST). Technical work packages are targeting filter wheel software for the VIS camera, additional IR filters, and an upgrade of the mirror coating facility by additional sputtering equipment.}, subject = {Spiegelteleskop}, language = {en} } @article{ProbstBegouDoehringetal.2018, author = {Probst, Anne-Catherine and Begou, Thomas and D{\"o}hring, Thorsten and Zeising, Sebastian and Stollenwerk, Manfred and Stadtm{\"u}ller, Johannes and Emmerich, Florian and Lumeau, Julien}, title = {Coating stress analysis and compensation for iridium-based x-ray mirrors}, series = {Applied Optics}, volume = {2018}, journal = {Applied Optics}, number = {57 (29)}, editor = {Publishing OSA,}, pages = {8775 -- 8779}, year = {2018}, abstract = {Iridium-based coatings for mirrors of x-ray telescopes are studied. In particular, stress-induced deformation is characterized and shown to be compressive and equal to -1786  MPa. Two methods for stress compensation are then studied. One relies on the deposition of silica on the back surface of the substrate and a second one relies on the deposition of a chromium sublayer. Advantages and drawbacks of each of these techniques are presented.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @misc{HudecPinaMarsikovaetal.2018, author = {Hudec, Rene and Pina, Ladislav and Marsikova, Veronika and Inneman, Adolf and D{\"o}hring, Thorsten}, title = {Kirkpatrick Baez X-ray Optics for Astrophysics: Recent Status}, editor = {Deutsche Gesellschaft f{\"u}r angewandte Optik,}, organization = {CVUT Prag}, pages = {1 -- 1}, year = {2018}, abstract = {X-ray optics in KB (Kirkpatrick Baez) arrangement represent promising alternative to Wolter optics in common use. We will present some new results including KB module developed and tested in X-rays within the EU AHEAD project.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @misc{HudecPinaMarsikovaetal.2018, author = {Hudec, Rene and Pina, Ladislav and Marsikova, Veronika and Inneman, Adolf and D{\"o}hring, Thorsten}, title = {Lobster Eye X-ray Optics for Astrophysics: Recent Status}, editor = {Deutsche Gesellschaft f{\"u}r angewandte Optik,}, organization = {CVUT Prag}, pages = {1 -- 1}, year = {2018}, abstract = {X-ray optics in LE (Lobster Eye) arrangement represent important part of future X-ray wide field telescopes and monitors. We will present some new results in the design, development, tests and applications of LE X-ray optics with emphasis on astrophysics.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @book{Doehring1993, author = {D{\"o}hring, Thorsten}, title = {Das laserinduzierte Plasma - eine R{\"o}ntgenlichtquelle}, publisher = {Technische Hochschule Aschaffenburg}, year = {1993}, abstract = {Dissertation}, subject = {Lasererzeugtes Plasma}, language = {de} } @misc{HartmannDoehringSchaefer2009, author = {Hartmann, Peter and D{\"o}hring, Thorsten and Sch{\"a}fer, Martin}, title = {Glass Ceramic ZERODUR® for Space Application}, series = {DGaO-Proceedings}, volume = {2009}, journal = {DGaO-Proceedings}, issn = {1614-8436}, year = {2009}, abstract = {Poster}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{KlingLucarelliHartmannetal.2009, author = {Kling, G{\"u}nther and Lucarelli, Stefano and Hartmann, Peter and Nattermann, Kurt and D{\"o}hring, Thorsten and Kuhr, Markus and Thomas, Peter}, title = {Double Ring Tests on ZERODUR K20 and Etched ZERODUR}, series = {Proceedings 11th European Conference on Spacecraft Structures, Materials and Mechanical Testing, 15-17 Sep 2009, Toulouse, France}, booktitle = {Proceedings 11th European Conference on Spacecraft Structures, Materials and Mechanical Testing, 15-17 Sep 2009, Toulouse, France}, year = {2009}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringJedamzikHartmann2007, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Hartmann, Peter}, title = {Mirrors for solar telescopes made from ZERODUR glass ceramic}, series = {Proceedings of SPIE}, volume = {6689}, booktitle = {Proceedings of SPIE}, number = {66890X}, year = {2007}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringJedamzik2007, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf}, title = {Manufacturing of lightweighted ZERODUR components at SCHOTT}, series = {Proceedings of SPIE}, volume = {6666}, booktitle = {Proceedings of SPIE}, number = {666602}, year = {2007}, subject = {Zerodur}, language = {en} } @inproceedings{HartmannNattermannDoehring2007, author = {Hartmann, Peter and Nattermann, Kurt and D{\"o}hring, Thorsten}, title = {Strength aspects for the design of ZERODUR glass ceramics structures}, series = {Proceedings of SPIE}, volume = {6666}, booktitle = {Proceedings of SPIE}, number = {666603}, year = {2007}, subject = {Zerodur}, language = {en} } @inproceedings{DoehringJedamzikHartmann2007, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Hartmann, Peter}, title = {ZERODUR mirror substrates for solar Telescopes}, series = {Modern Solar Facilities - Advanced Solar Science : Proceedings of a Workshop held at G{\"o}ttingen September 27-29, 2006}, booktitle = {Modern Solar Facilities - Advanced Solar Science : Proceedings of a Workshop held at G{\"o}ttingen September 27-29, 2006}, publisher = {Universit{\"a}tsverlag}, address = {G{\"o}ttingen}, pages = {77 -- 82}, year = {2007}, subject = {Zerodur}, language = {en} } @inproceedings{DoehringLoosenHartmann2006, author = {D{\"o}hring, Thorsten and Loosen, Klaus-Dieter and Hartmann, Peter}, title = {The technical challenge of large ELT filters}, series = {Proceedings of SPIE}, volume = {6273}, booktitle = {Proceedings of SPIE}, number = {62730U}, year = {2006}, subject = {Filter}, language = {en} } @inproceedings{DoehringHartmannJedamzik2006, author = {D{\"o}hring, Thorsten and Hartmann, Peter and Jedamzik, Ralf}, title = {Properties of Zerodur mirror blanks for extremely large telescopes}, series = {Proceedings of SPIE}, volume = {6148}, booktitle = {Proceedings of SPIE}, number = {61480G}, year = {2006}, subject = {Zerodur}, language = {en} } @inproceedings{DoehringHartmannJedamzik2005, author = {D{\"o}hring, Thorsten and Hartmann, Peter and Jedamzik, Ralf}, title = {Status of ZERODUR mirror blank production at SCHOTT}, series = {Proceedings of SPIE}, volume = {5869}, booktitle = {Proceedings of SPIE}, number = {586902}, year = {2005}, subject = {Zerodur}, language = {en} } @inproceedings{JedamzikDoehringMueller2005, author = {Jedamzik, Ralf and D{\"o}hring, Thorsten and M{\"u}ller, Rolf}, title = {Homogeneity of the coefficient of linear thermal expansion of ZERODUR}, series = {Proceedings of SPIE}, volume = {5868}, booktitle = {Proceedings of SPIE}, number = {58680S}, year = {2005}, subject = {Zerodur}, language = {en} } @inproceedings{HartmannNattermannDoehring2008, author = {Hartmann, Peter and Nattermann, Kurt and D{\"o}hring, Thorsten}, title = {ZERODUR glass ceramics: strength data for the design of structures with high mechanical stresses}, series = {Proceedings of SPIE}, volume = {7018}, booktitle = {Proceedings of SPIE}, number = {70180O}, year = {2008}, subject = {Glaskeramik}, language = {en} } @inproceedings{DoehringJedamzikThomasetal.2008, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Thomas, Armin and Hartmann, Peter}, title = {Forty years of ZERODUR mirror substrates for astronomy: review and outlook}, volume = {7018}, number = {70183B}, year = {2008}, subject = {Spiegelteleskop}, language = {en} } @article{DoehringSchreiber2008, author = {D{\"o}hring, Thorsten and Schreiber, Ulrich}, title = {Glaskeramik - Fundament f{\"u}r h{\"o}chste Pr{\"a}zision}, series = {Photonik}, journal = {Photonik}, number = {2}, issn = {1432-9778}, pages = {52 -- 55}, year = {2008}, subject = {Glaskeramik}, language = {de} } @misc{DoehringHudec2018, author = {D{\"o}hring, Thorsten and Hudec, Rene}, title = {Optics development for X-ray astronomy - a review on four joint Bavarian-Czech projects}, organization = {Hochschule Aschaffenburg}, pages = {1 -- 1}, year = {2018}, abstract = {In the years 2016 to 2018 the Bavarian-Czech Academic Agency (BTHA) funded in summary four bilateral projects between Aschaffenburg University and CVUT Prague: JEUMICO, TRILAMICO, JODEXRA, and AXROCO. The effective combination of equipment, manpower, and know-how of both partners resulted in the development of stress-compensated iridium coatings for astronomical X-ray mirrors. The findings have been published at scientific conferences and in joint papers. This poster gives a review on the social , political and educational aspects of the collaborations in form of a photo documentation.}, subject = {R{\"o}ntgenspiegel}, language = {en} } @misc{DoehringGoeslingPribullaetal.2019, author = {D{\"o}hring, Thorsten and G{\"o}sling, Lukas and Pribulla, Theodor and Komzik, Richard}, title = {Segmented infrared filters for the 1.3m telescope in the Slovak Tatra Mountains}, organization = {TH Aschaffenburg}, pages = {1}, year = {2019}, abstract = {Since 2015, the Astronomical Institute of the Slovak Academy of Sciences (AI SAS) is operating a modern EU-funded reflecting telescope with a 130 cm primary mirror, located in the Skalnat{\´e} Pleso Observatory in the Tatra Mountains at an altitude of 1783 m. In 2018, the funding agency BAYHOST granted the proposed project SLOBATCO to Aschaffenburg University of Applied Sciences. The cooperation project pursues the development of astronomical NIR filters, which are designed for the atmospheric transmission windows in the infrared spectral range. In order to avoid a complex cryogenic filter wheel for the NIR CCD camera operated at low temperatures, the observations should be realized through a segmented filter using precise shifts of the image field. The bi-national cooperation project and the specification of the infrared filter combination are presented in this poster contribution.}, subject = {Spiegelteleskop}, language = {en} } @incollection{Doehring2019, author = {D{\"o}hring, Thorsten}, title = {Hochschule Aschaffenburg}, series = {Deutsche Raumfahrtakteure : Bundesl{\"a}nder - Organisation - Raumfahrt - raumfahrtbasierte Anwendungen}, booktitle = {Deutsche Raumfahrtakteure : Bundesl{\"a}nder - Organisation - Raumfahrt - raumfahrtbasierte Anwendungen}, publisher = {Deutsches Zentrum f{\"u}r Luft- und Raumfahrt e. V. (DLR)}, address = {K{\"o}ln}, pages = {87 -- 87}, year = {2019}, abstract = {Die Hochschule Aschaffenburg zeichnet sich durch wirtschaftsnahe, {\"u}berwiegend interdisziplin{\"a}re und innovative Studieng{\"a}nge aus. Enge Kooperationen mit Unternehmen sowie Partnerschaften mit ausl{\"a}ndischen Hochschulen garantieren den Studierenden, dass sie praxisrelevantes Wissen erwerben, welches f{\"u}r eine erfolgreiche Arbeit in einer zunehmend globalen Arbeitswelt erforderlich ist. Professorinnen und Professoren der Fakult{\"a}t Ingenieurwissenschaften sind mit ihren Forschungsteams {\"u}ber internationale Kooperationen an mehreren Raumfahrtprojekten beteiligt. Es werden Spiegelschichten f{\"u}r R{\"o}ntgensatelliten entwickelt, Katalysatoren f{\"u}r Raketentriebwerke beschichtet und die Auswirkungen kosmischer Strahlung auf das Herz-Kreislauf-System und auf Gehirnzellen untersucht. Die Ergebnisse werden in wissenschaftlichen Publikationen und auf Fachkonferenzen pr{\"a}sentiert. Studierende sind {\"u}ber Spezialvorlesungen und Abschlussarbeiten zu Raumfahrtthemen hierbei mit eingebunden.}, subject = {Raumfahrttechnik}, language = {de} } @incollection{DoehringKrausseSchneiderStoermann2018, author = {D{\"o}hring, Thorsten and Krauße, Sylvana and Schneider-St{\"o}rmann, Ludger}, title = {Der Studiengang Internationales Technisches Vertriebsmanagement an der Hochschule Aschaffenburg - Ausbildung von Vertriebsingenieuren f{\"u}r einen globalen Markt}, series = {Internationalisierung der Curricula in den MINT-F{\"a}chern}, booktitle = {Internationalisierung der Curricula in den MINT-F{\"a}chern}, publisher = {wbv Media}, address = {Bielefeld}, doi = {10.3278/6004649w}, pages = {161 -- 170}, year = {2018}, abstract = {Die Wettbewerbsf{\"a}higkeit der Exportnation Deutschland erfordert hervorragend ausgebildete Vertriebsingenieure. Dieses Ausbildungsziel verfolgt der Studiengang „Internationales Technisches Vertriebsmanagement" an der Hochschule Aschaffenburg. Als Besonderheit komplettiert ein f{\"u}r alle Studierende verpflichtender Auslandsaufenthalt die international ausgerichtete Ausbildung. Neben Lehrveranstaltungen in englischer Sprache gibt es eine internationale Projektwoche als Maßnahme zur "Internationalisation at Home". Der Studiengang ist {\"u}ber die „Academic Association of Sales Engineering" international vernetzt.}, language = {de} } @inproceedings{DoehringHartmann2005, author = {D{\"o}hring, Thorsten and Hartmann, Peter}, title = {Large Lenses and Filters for ELTs : Challenges and Opportunities for SCHOTT}, series = {Instrumentation for Extremely Large Telescopes : Proceedings of a Workshop held at Ringberg Castle ; 25-29 July 2005}, booktitle = {Instrumentation for Extremely Large Telescopes : Proceedings of a Workshop held at Ringberg Castle ; 25-29 July 2005}, publisher = {MPIA}, address = {Heidelberg}, pages = {33 -- 37}, year = {2005}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{HartmannDoehring2005, author = {Hartmann, Peter and D{\"o}hring, Thorsten}, title = {Mirror blank production for ELTs}, series = {Instrumentation for Extremely Large Telescopes : a Workshop held at Ringberg Castle, Bavaria, 25-29 July 2005 ; proceedings}, booktitle = {Instrumentation for Extremely Large Telescopes : a Workshop held at Ringberg Castle, Bavaria, 25-29 July 2005 ; proceedings}, publisher = {Max-Planck-Institut f{\"u}r Astronomie}, address = {Heidelberg}, year = {2005}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringJedamzikWittmer2004, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Wittmer, Volker}, title = {Production of the 4.1-m Zerodur mirror blank for the VISTA Telescope}, series = {Proceedings of SPIE}, volume = {5494}, booktitle = {Proceedings of SPIE}, pages = {340 -- 349}, year = {2004}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringHartmannJedamzik2004, author = {D{\"o}hring, Thorsten and Hartmann, Peter and Jedamzik, Ralf}, title = {ZERODUR mirror blanks for ELTs: technology and production capacity at SCHOTT}, series = {Proceedings of SPIE}, volume = {5382}, booktitle = {Proceedings of SPIE}, pages = {285 -- 295}, year = {2004}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringJedamzikHartmann2004, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Hartmann, Peter}, title = {Forming mandrels for x-ray telescopes made of modified Zerodur}, series = {Proceedings of SPIE}, volume = {5168}, booktitle = {Proceedings of SPIE}, pages = {148 -- 156}, year = {2004}, subject = {Zerodur}, language = {en} } @inproceedings{GhigoCitterioMazzolenietal.2004, author = {Ghigo, Mauro and Citterio, Oberto and Mazzoleni, Francesco and Pareschi, Giovanni and Aschenbach, Bernd and Br{\"a}uninger, Heinrich W. and Friedrich, Peter and Hasinger, G{\"u}nther and D{\"o}hring, Thorsten and Esemann, Hauke and Jedamzik, Ralf and H{\"o}lzel, Eva and Parodi, Giancarlo}, title = {The manufacturing of the XEUS x-ray glass segmented mirrors: status of the investigation and last results}, series = {Proceedings of SPIE}, volume = {5168}, booktitle = {Proceedings of SPIE}, pages = {180 -- 195}, year = {2004}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringJedamzikThomas2003, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Thomas, Armin}, title = {Zerodur mandrels for the next generation of x-ray telescopes}, series = {Proceedings of SPIE}, volume = {4851}, booktitle = {Proceedings of SPIE}, pages = {647 -- 655}, year = {2003}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{DoehringHartmannMorian2003, author = {D{\"o}hring, Thorsten and Hartmann, Peter and Morian, Hans F.}, title = {Optical glasses and glass ceramics for large optical systems}, series = {Proceedings of SPIE}, volume = {4842}, booktitle = {Proceedings of SPIE}, pages = {56 -- 66}, year = {2003}, subject = {Zerodur}, language = {en} } @article{DoehringMorian2000, author = {D{\"o}hring, Thorsten and Morian, Hans F.}, title = {An eye on the sky}, series = {GLASS - Monthly Journal of the European Glass Industry}, volume = {2000}, journal = {GLASS - Monthly Journal of the European Glass Industry}, number = {77}, pages = {370 -- 371}, year = {2000}, subject = {Glas}, language = {en} } @inproceedings{AltmannEgleHafneretal.2000, author = {Altmann, J{\"u}rgen and Egle, Wilhelm J. and Hafner, Wolfgang and Derst, Gerhard and Matthes, Axel and D{\"o}hring, Thorsten}, title = {Fabrication of a demonstration mandrel for ESA's XEUS mirror development program}, series = {Proceedings of SPIE}, volume = {4012}, booktitle = {Proceedings of SPIE}, pages = {559 -- 566}, year = {2000}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{FriedrichBraeuningerBurkertetal.1998, author = {Friedrich, Peter and Br{\"a}uninger, Heinrich W. and Burkert, Wolfgang and D{\"o}hring, Thorsten and Egger, Roland and Hasinger, G{\"u}nther and Oppitz, Andreas and Predehl, Peter and Tr{\"u}mper, Joachim Ernst}, title = {X-ray tests and calibrations of the ABRIXAS mirror systems}, series = {Proceedings of SPIE}, volume = {3444}, booktitle = {Proceedings of SPIE}, pages = {369 -- 379}, year = {1998}, subject = {Spiegelteleskop}, language = {en} } @article{DoehringAschenbachBraeuningeretal.1998, author = {D{\"o}hring, Thorsten and Aschenbach, Bernd and Br{\"a}uninger, Heinrich W. and Briel, Ulrich G. and Burkert, Wolfgang and Egger, Roland and Hasinger, G{\"u}nther and Hippmann, Horst and Kendziorra, Eckhard and Oppitz, Andreas and Pfeffermann, Elmar and Predehl, Peter and Str{\"u}der, Lothar and Tr{\"u}mper, Joachim Ernst}, title = {X-ray qualification of the ABRIXAS telescope}, series = {Astronomical Notes - Astronomische Nachrichten}, volume = {319}, journal = {Astronomical Notes - Astronomische Nachrichten}, number = {1-2}, pages = {140 -- 140}, year = {1998}, subject = {Spiegelteleskop}, language = {en} } @article{DoehringAschenbachBraeuningeretal.1997, author = {D{\"o}hring, Thorsten and Aschenbach, Bernd and Br{\"a}uninger, Heinrich W. and Burkert, Wolfgang and Egger, Roland and Oppitz, Andreas}, title = {Charakterisierung von R{\"o}ntgensatelliten}, series = {Hf-Report: Hochfrequenztechnik, Optoelektronik, Mikrowellentechnik, Kommunikationstechnik}, volume = {11}, journal = {Hf-Report: Hochfrequenztechnik, Optoelektronik, Mikrowellentechnik, Kommunikationstechnik}, number = {4}, pages = {30 -- 34}, year = {1997}, subject = {R{\"o}ntgenstrahlung}, language = {de} } @article{DoehringSchreiber2009, author = {D{\"o}hring, Thorsten and Schreiber, Ulrich}, title = {Glass ceramics - foundation for highest precision}, series = {Photonik international}, volume = {2009}, journal = {Photonik international}, number = {1}, pages = {17 -- 19}, year = {2009}, subject = {Glaskeramik}, language = {de} } @inproceedings{JedamzikDoehringJohannsson2009, author = {Jedamzik, Ralf and D{\"o}hring, Thorsten and Johannsson, Thoralf}, title = {CTE characterization of ZERODUR® for the ELT century}, series = {Proceedings of SPIE}, volume = {7425}, booktitle = {Proceedings of SPIE}, number = {742504}, year = {2009}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringHartmannLentes2009, author = {D{\"o}hring, Thorsten and Hartmann, Peter and Lentes, Frank-Thomas}, title = {Heritage of ZERODUR® glass ceramic for space applications}, series = {Proceedings of SPIE}, volume = {7425}, booktitle = {Proceedings of SPIE}, number = {74250L}, year = {2009}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{HartmannNattermannDoehring2009, author = {Hartmann, Peter and Nattermann, Kurt and D{\"o}hring, Thorsten}, title = {ZERODUR® glass ceramics for high stress applications}, series = {Proceedings of SPIE}, volume = {7425}, booktitle = {Proceedings of SPIE}, number = {74250M}, year = {2009}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringJedamzikWesterhoff2009, author = {D{\"o}hring, Thorsten and Jedamzik, Ralf and Westerhoff, Thomas}, title = {Four decades of ZERODUR mirror substrates for astronomy}, series = {Proceedings of SPIE}, volume = {7281}, booktitle = {Proceedings of SPIE}, number = {728103}, year = {2009}, subject = {Spiegelteleskop}, language = {en} } @article{Doehring2008, author = {D{\"o}hring, Thorsten}, title = {From Heidelberg to Hawaii: SCHOTT's Century of Astronomy}, series = {400 Years of the Telescope Newsletter}, volume = {1}, journal = {400 Years of the Telescope Newsletter}, number = {9}, pages = {2 -- 7}, year = {2008}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{JedamzikHengstElsmannetal.2008, author = {Jedamzik, Ralf and Hengst, Joachim and Elsmann, Frank and Lemke, Christian and D{\"o}hring, Thorsten and Hartmann, Peter}, title = {Optical materials for astronomy from SCHOTT: the quality of large components}, series = {Proceedings of SPIE}, volume = {7018}, booktitle = {Proceedings of SPIE}, number = {70180O}, year = {2008}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{KriegCarreDoehringetal.2022, author = {Krieg, Janina and Carre, Antoine and D{\"o}hring, Thorsten and Hartmann, Peter and Hull, Tony and Jedamzik, Ralf and Westerhoff, Thomas}, title = {The past decade of ZERODUR® glass-ceramics in space applications}, series = {Proceedings of SPIE}, volume = {2022}, booktitle = {Proceedings of SPIE}, number = {12180}, publisher = {SPIE}, organization = {SCHOTT AG}, doi = {https://doi.org/10.1117/12.2628956}, pages = {121805N-1 -- 121805N-15}, year = {2022}, abstract = {For the past four decades, ZERODUR® glass ceramics has flown on many satellites including the prominent space missions METEOSAT, Hubble Space Telescope, CHANDRA, and LISA pathfinder. Firstly, this unique material is chosen as mirror substrate for high precision optics due to its extreme thermal stability. Its near-zero thermal expansion over a wide temperature range of several tens of Kelvin is homogenous within the entire volume. This enables control of the ZERODUR®'s surface profile at the 10-picometer level. SCHOTT has conducted comprehensive material characteristics studies on the mechanical properties and the radiation environment effects experienced in realistic orbits to define the suitability of ZERODUR® to survive both high loads during launch and to support long-term missions, respectively. Besides these advantageous material properties, this glass-ceramics can be extremely light-weighted by precision grinding enabled by the new SCHOTT competence center for machining and metrology. In this paper, we will continue to trace the recent developments of ZERODUR® glass ceramics as space material in the context of selected missions flown since 2009 and those anticipated. Major milestones such as the LISA pathfinder mission are discussed. Furthermore, we outline the viable use of ZERODUR® for great observatory architectures for IR/O/UV spaceborne telescopes. The objective of this paper is to supplement an earlier review of the use of ZERODUR® for space applications in the past decade and to summarize the latest progress and results of material studies toward very efficient production capabilities for high-performance light-weighted mirror substrates.}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{DoehringZeisingStieglitzetal.2022, author = {D{\"o}hring, Thorsten and Zeising, Sebastian and Stieglitz, Veronika and Burwitz, Vadim and Rukdee, Surangkhana and Friedrich, Peter and Jelinek, Martin and Hudec, Rene}, title = {R{\"o}ntgenteleskop-Funktionstests durch Beobachtung astronomischer Objekte am sichtbaren Nachthimmel}, series = {DGaO Proceedings}, volume = {2022}, booktitle = {DGaO Proceedings}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2022}, abstract = {Lobster-Eye-R{\"o}ntgenteleskope nutzen reflektierende Planspiegel unter streifendem Einfall und zeichnen sich durch ein großes Beobachtungsfeld aus. Die Spiegel reflektieren auch sichtbare Strahlung hervorragend. Nach R{\"o}ntgen-messungen im Labor wurden nun weitere Tests durchgef{\"u}hrt, um die Abbildungs-eigenschaften mit realen Objekten des sichtbaren Himmels zu untersuchen.}, subject = {R{\"o}ntgenteleskop}, language = {de} } @inproceedings{DoehringStollenwerkSchmittetal.2022, author = {D{\"o}hring, Thorsten and Stollenwerk, Manfred and Schmitt, Paul and Szeghalmi, Andrea}, title = {Umweltbest{\"a}ndige Spiegelbeschichtungen aus Iridium f{\"u}r den infraroten Spektralbereich}, series = {DGaO Proceedings}, volume = {2022}, booktitle = {DGaO Proceedings}, number = {123}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2022}, abstract = {Das Edelmetall Iridium ist hart; extrem dicht; thermisch, mechanisch und chemisch stabil; weist eine hohe Reflektivit{\"a}t im mittleren und fernen Infrarot auf und hat eine hohe Best{\"a}ndigkeit gegen{\"u}ber Umwelteinfl{\"u}ssen - auch ohne weitere Schutzschichten. Es wurden die komplexen Brechungsindizes f{\"u}r Iridium-Spiegelbeschichtungen bestimmt, welche vorhandene Literaturwerte erg{\"a}nzen.}, subject = {Iridium}, language = {de} } @inproceedings{HudecGilleGuimbelotetal.2022, author = {Hudec, Rene and Gille, Florian and Guimbelot, Elzear and Tichy, Vladimir and D{\"o}hring, Thorsten}, title = {Effective areas of astronomical X-ray optics for cubesats and rocket experiments}, series = {DGaO Proceedings}, volume = {2022}, booktitle = {DGaO Proceedings}, number = {123}, publisher = {DGaO}, organization = {Technische Universit{\"a}t Prag}, issn = {1614-8436}, pages = {1 -- 2}, year = {2022}, abstract = {The effective area is one of the main telescope parameters when justifying real space application. We discuss the estimation of the effective collecting area of an X-ray telescope by two different methods, an analytical method and a simulation algorithm, and then compare the results. The Lobster Eye type telescopes considered here are designed for rocket experiments and CubeSat flights.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @article{SchmittFeldeDoehringetal.2022, author = {Schmitt, Paul and Felde, Nadja and D{\"o}hring, Thorsten and Stollenwerk, Manfred and Uschmann, Ingo and Hanemann, Kevin and Siegler, Marie and Klemm, Georg and Gratzke, Nancy and T{\"u}nnermann, Andreas and Schwinde, Stefan and Schr{\"o}der, Sven and Szeghalmi, Adriana}, title = {Optical, structural, and functional properties of highly reflective and stable iridium mirror coatings for infrared applications}, series = {Optical Materials Express}, volume = {2022}, journal = {Optical Materials Express}, number = {12 / 2}, doi = {10.1364/OME.447306}, pages = {545 -- 559}, year = {2022}, abstract = {Metallic coatings are essential for numerous optical systems due to their high and broadband refl ectivity in the infrared spectral range. In contrast to well-established (protected)silver and gold mirror coatings, iridium is environmentally durable, referring to ISO 9211-3 and thermally stable up to 600 °C even without protective layers, as demonstrated. Additionally,the optical and related structural properties of atomic layer deposited (ALD) and magnetron sputtered (MS) Ir coatings were investigated using spectrophotometry, FTIR, ellipsometry, WLI,AFM, XRR, XRD, SEM, and electrical resistivity measurements. The properties of Ir ALD and Ir MS coatings diff er due to their topography and microstructure.}, subject = {Iridium}, language = {en} } @article{SchmittFeldeDoehringetal.2022, author = {Schmitt, Paul and Felde, Nadja and D{\"o}hring, Thorsten and Stollenwerk, Manfred and Uschmann, Ingo and Hanemann, Kevin and Siegler, Marie and Klemm, Georg and Gratzke, Nancy and T{\"u}nnermann, Andreas and Schwinde, Stefan and Schr{\"o}der, Sven and Szeghalmi, Adriana}, title = {Optical, structural, and functional properties of highly reflective and stable iridium mirrorcoatings for infrared applications: supplement}, series = {Optical Materials Express}, volume = {2022}, journal = {Optical Materials Express}, number = {12/2}, doi = {10.6084/m9.figshare.17121509}, pages = {545 -- 559}, year = {2022}, abstract = {Metallic coatings are essential for numerous optical systems due to their high and broadband refl ectivity in the infrared spectral range. In contrast to well-established (protected)silver and gold mirror coatings, iridium is environmentally durable, referring to ISO 9211-3 and thermally stable up to 600 °C even without protective layers, as demonstrated. Additionally,the optical and related structural properties of atomic layer deposited (ALD) and magnetron sputtered (MS) Ir coatings were investigated using spectrophotometry, FTIR, ellipsometry, WLI, AFM, XRR, XRD, SEM, and electrical resistivity measurements. The properties of Ir ALD and Ir MS coatings diff er due to their topography and microstructure.}, subject = {Iridium}, language = {en} } @misc{DoehringStollenwerkSchmittetal.2022, author = {D{\"o}hring, Thorsten and Stollenwerk, Manfred and Schmitt, Paul and Szeghalmi, Adriana}, title = {Umweltbest{\"a}ndige Spiegelbeschichtungen aus Iridium f{\"u}r den infraroten Spektralbereich}, publisher = {DGaO}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2022}, abstract = {Hochreflektierende Metallbeschichtungen sind essenziell f{\"u}r zahlreiche optische Elemente. Bew{\"a}hrte Spiegelbeschichtungen aus Silber und Gold bieten eine hohe und breitbandige Eigenreflexion im infraroten Spektralbereich, sind ohne geeignete Schutzschichten jedoch anf{\"a}llig gegen{\"u}ber Umwelteinfl{\"u}ssen und mechanischer Beanspruchung. Insbesondere im langwelligen Spektralbereich verringern die Absorptionsbanden dieser Schutzschichten teilweise die hohe Spiegelreflektivit{\"a}t wieder. Das Edelmetall Iridium (Ir) ist hart; extrem dicht; thermisch, mechanisch und chemisch stabil; weist eine {\"a}hnlich hohe Reflektivit{\"a}t im mittleren und fernen Infrarot, wie Silber und Gold, auf und hat zus{\"a}tzlich eine hohe Best{\"a}ndigkeit gegen{\"u}ber Umwelteinfl{\"u}ssen - auch ohne Schutzschichten. In diesem Beitrag werden die optischen und strukturellen Eigenschaften von Iridium-Spiegelbeschichtungen, welche mittels Atomlagenabscheidung (ALD) und DC-Magnetron-Sputtern hergestellt wurden, vorgestellt und miteinander verglichen. Die komplexen Brechungsindizes f{\"u}r ALD-erzeugte und gesputterte Iridium-Spiegelbeschichtungen wurden f{\"u}r Wellenl{\"a}ngen von 200 nm bis 20 μm bestimmt, welche nun bereits vorhandene Literaturwerte erg{\"a}nzen.}, subject = {Iridium}, language = {de} } @misc{HudecGilleGuimbelotetal.2022, author = {Hudec, Rene and Gille, Florian and Guimbelot, Elzear and Tichy, Vladimir and D{\"o}hring, Thorsten}, title = {Effective areas of astronomical X-ray optics for cubesats and rocket experiments}, publisher = {DGaO}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2022}, abstract = {We address the problem of estimation the sensitivity of astronomical X-ray telescopes of Lobster Eye type , with emphasis on calculation of effective areas for telescopes designed for rocket and CubeSat flights. This parameter is one of the principal parameters when justifying the real space application. Indeed, the larger the effective area is, the more efficient the optical system is, able to provide images of fainter and more distant celestial targets. We discuss the estimation of the effective collecting area of a X-ray telescope by two different methods and then compare the results: the analytical method and then the simulation algorithm.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{DoehringStollenwerkSchmittetal.2022, author = {D{\"o}hring, Thorsten and Stollenwerk, Manfred and Schmitt, Paul and Szeghalmi, Adriana}, title = {Environmentally stable iridium mirror coatings for the infrared spectral range}, series = {Proceedings of SPIE}, volume = {2022}, booktitle = {Proceedings of SPIE}, number = {12298}, publisher = {SPIE}, organization = {TH Aschaffenburg}, doi = {https://doi.org/10.1117/12.2632057}, pages = {122980A-1 -- 122980A-08}, year = {2022}, abstract = {Highly reflective metal coatings are essential for numerous optical elements. Established mirror coatings made of silver (Ag) and gold (Au) offer high and broadband self-reflection in the infrared (IR) spectral range but are susceptible to environmental influences and mechanical stress without suitable protective layers. In the long-wavelength spectral range, in particular, the absorption bands of these protective layers partially reduce the high mirror reflectivity again. However, the noble metal iridium (Ir) is hard, extremely dense, and thermally, mechanically, and chemically stable. Iridium provides a similarly high reflectivity in the mid (MIR) and far-infrared (FIR) spectral range, as silver and gold, and high resistance to environmental influences - even without protective layers. In this paper, the different deposition processes, as well as the optical and structural properties of iridium mirror coatings fabricated by atomic layer deposition (ALD) and by magnetron sputtering (MS), are presented and compared with each other. The complex refractive indices for ALD and MS deposited iridium mirror coatings were determined for wavelengths from 200 nm to 20 μm, complementing the existing literature values. We demonstrate that iridium mirror coatings offer a high and broadband reflectivity from the mid to far-infrared spectral range. In contrast to established - protected - silver and gold mirror coatings, the iridium coatings are environmentally durable and thermally stable up to 600 °C, even without protective layers. Therefore, as an interesting mirror coating material, iridium has the potential for special applications in infrared astronomy and probably also for industrial instruments.}, subject = {Iridium}, language = {en} } @inproceedings{DoehringStieglitzHudecetal.2022, author = {D{\"o}hring, Thorsten and Stieglitz, Veronika and Hudec, Rene and Sapsai, Iryna and Friedrich, Peter and Burwitz, Vadim}, title = {Characterization of a lobster-eye type X-ray telescope}, series = {EOSAM-Conference}, volume = {2022}, booktitle = {EOSAM-Conference}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2022}, abstract = {Lobster-eye type X-ray telescopes use reflecting plano mirrors under grazing incidence and can observe a large field of view. As part of a Bavarian-Czech cooperation, two telescopes were build, equipped with mirrors coated with gold and iridium. Their X-ray characterization was carried out at the PANTER test facility, which simulates parallel starlight incident on the telescopes. The telescopes have an angular resolution of about 4 arc minutes in X-rays and a focal length of about 2 meters. The used X-ray mirrors reflect and focus visible light as well; their functionality in the optical regime was checked in laboratory tests. Now another test campaign will be carried out to examine the telescope resolution for real objects of the visible night sky and the imaging properties for star constellations.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @misc{DoehringRoedlingKimmeletal.2021, author = {D{\"o}hring, Thorsten and R{\"o}dling, Claudius and Kimmel, Kevin and Zeising, Sebastian and Stadtm{\"u}ller, Johannes and Stollenwerk, Manfred and Verma, Shruti and Rees, Paul}, title = {Optical characterization of reflective coatings for astronomical telescope mirrors}, series = {DGaO Jahrestagung}, volume = {2021}, journal = {DGaO Jahrestagung}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2021}, abstract = {With ground based optical telescopes astronomers observe celestial objects over a wide spectral range. As usually three or even more reflections at telescope mirrors are involved, good reflection properties of the mirror coatings are important. The aluminum evaporation technique has been - and is still - the standard solution for the reflective coatings of large astronomical mirrors. Such coatings have excellent reflectivity in the ultraviolet and in the visible, but perform poorly in the infrared. Silver is the metal having highest reflectivity for wavelengths longward of 400 nm, but isn´t the best choice for reflectivity in the ultraviolet and for blue light. To avoid degradation by oxidation, durable silver coatings need to be protected by transmitting overcoating layers. In the presented study, different metallic coatings - including unusual ones like sputtered iridium - are characterized to identify a coating that is most suitable for the spectral range from ultraviolet to infrared. Experimental results are compared to simulations based on the complex refractive indices of these materials. Thereby dependence of incidence angle and polarization is also considered.}, subject = {Spiegelteleskop}, language = {en} } @inproceedings{FreudenmannStollenwerkDoehringetal.2021, author = {Freudenmann, Dominic and Stollenwerk, Manfred and D{\"o}hring, Thorsten and Stadtm{\"u}ller, Johannes and Negri, Michele and Lauck, Felix}, title = {Combustion efficiency of iridium coated pellets for environmentally friendly space propulsion}, series = {14th Pico- and Nanosatellite Workshop, W{\"u}rzburg, Germany}, booktitle = {14th Pico- and Nanosatellite Workshop, W{\"u}rzburg, Germany}, year = {2021}, abstract = {Most of the satellite engines still uses critical fuels such as hydrazine, which is chemically aggressive, toxic and carcinogenic. New developments for satellite engines try to avoid such critical propellants. One promising approach is the usage of rocket-grade hydrogen peroxide [H2O2] in mono- and bipropellant driven rocket engines. Catalysts in the rocket engines convert the hydrogen peroxide by an exothermic catalytic reaction; the resulting hot gases oxygen and water vapor provide the thrust. Currently used catalysts are, for example, Al2O3 pellets impregnated with platinum. Within a joint research project of Aschaffenburg University and the German Aerospace Center new catalysts are developed. They consist of ceramic pellets coated with iridium using the magnetron sputtering process. Thereby the surface structure of the iridium layers strongly depends on the used sputtering process conditions [1]. After optimization of the sputtering parameters, it was demonstrated in laboratory experiments that the catalytic effect (measured by the volume of released gas) can be increased by a factor of four compared to platinum impregnated pellets [2]. In first hot firing tests at the test bench complex M11 at the DLR- Institute of Space Propulsion, these new, iridium-based catalysts have been used in a model combustion chamber for hydrogen peroxide decomposition. For this purpose, the reaction chamber was filled with iridium pellets in the high-altitude simulation chamber of the M11.2 test bench. The model chamber was equipped with numerous measuring devices like temperature and pressure sensors (e.g. Tcat, pcat). With the help of the mass flow and the herein obtained data, performance characteristics of the propellant system were accessible. High-concentrated hydrogen peroxide was used in the experiments as monopropellant (~ 87-wt.\% H2O2). During the experiments, the combustion chamber was operated in pulse mode and in continuous mode. Aim of this campaign called MoCa ("Monopropellant Catalytic Demonstrator") is the demonstration of functionality and the performance evaluation of this iridium-based monopropellant system. Recent experimental results will be presented. References: [1] A. B{\"u}ttner et al., Thin Solid Films 2018, 662: 41-46 [2] M. Stollenwerk et al., Journal of Materials Science 2021, 56(16), 9974-9984}, subject = {Satellitentechnik}, language = {de} } @inproceedings{DoehringStieglitzBurwitzetal.2021, author = {D{\"o}hring, Thorsten and Stieglitz, Veronika and Burwitz, Vadim and Hartner, Gisela and M{\"u}ller, Thomas and Schmidt, Thomas and Rukdee, Surangkhana and Friedrich, Peter and Sahin, Fatih and Hudec, Rene}, title = {Charakterisierung von Weitwinkel-R{\"o}ntgenteleskopen in der Testanlage PANTER}, series = {DGaO Proceedings}, volume = {2021}, booktitle = {DGaO Proceedings}, number = {122}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2021}, abstract = {Im Rahmen einer bayerisch-tschechischen Kooperation entstanden zwei R{\"o}ntgenteleskope, best{\"u}ckt mit Gold- und Iridium-beschichteten Planspiegeln. Deren Charakterisierung erfolgte an der R{\"o}ntgentestanlage PANTER, welche parallel auf die Teleskope einfallendes Sternenlicht simuliert. Die Teleskope haben eine Winkelaufl{\"o}sung von ca. 4 Bogenminuten und eine Brennweite von rund 2 Metern.}, subject = {R{\"o}ntgenteleskop}, language = {de} } @inproceedings{DoehringStadtmuellerStollenwerketal.2021, author = {D{\"o}hring, Thorsten and Stadtm{\"u}ller, Johannes and Stollenwerk, Manfred and Cotroneo, Vincenzo and Pareschi, Giovanni and Gibertini, Eugenio and Magagnin, Luca}, title = {Low-density coatings for enhanced X-ray reflectivity of astronomical telescope mirrors}, series = {DGaO Proceedings}, volume = {2021}, booktitle = {DGaO Proceedings}, number = {122}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2021}, abstract = {High reflectivity grazing incidence mirrors of astronomical X-ray telescopes are usually coated with thin layers of iridium, gold, or platinum. Due to a series of absorption edges, these noble metals have low reflectivity in the 2 - 4 keV band. We present the development of innovative material combinations using chromium and an additional layer of polydopamine for enhanced reflectivity X-ray coatings.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{DoehringRoedlingKimmeletal.2021, author = {D{\"o}hring, Thorsten and R{\"o}dling, Claudius and Kimmel, Kevin and Zeising, Sebastian and Stadtm{\"u}ller, Johannes and Stollenwerk, Manfred and Verma, Shruti and Rees, Paul}, title = {Optical characterization of reflective coatings for astronomical telescope mirrors}, series = {DGaO Proceedings}, volume = {2021}, booktitle = {DGaO Proceedings}, number = {122}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 1}, year = {2021}, abstract = {Aluminium evaporation is still the standard solution for reflective coatings of large astronomical mirrors. Silver and gold are also used in specific cases depending on the targeted wavelength. This study characterized different metallic coatings - including unusual ones like sputtered iridium - to identify the most suitable mirror coating for the spectral range from ultraviolet to infrared wavelengths.}, subject = {Spiegelteleskop}, language = {en} } @misc{DoehringStadtmuellerStollenwerketal.2021, author = {D{\"o}hring, Thorsten and Stadtm{\"u}ller, Johannes and Stollenwerk, Manfred and Cotroneo, Vincenzo and Pareschi, Giovanni and Gibertini, Eugenio and Magagnin, Luca}, title = {Low-density coatings for enhanced X-ray reflectivity of astronomical telescope mirrors}, series = {DGaO Jahrestagung}, volume = {2021}, journal = {DGaO Jahrestagung}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2021}, abstract = {X-ray telescopes usually operate in space and are quite different from astronomical telescopes for visible light. For normal angles of incidence, optical light is reflected on the mirror surface, whereas X-rays are either transmitted or absorbed. However, also high reflectivity X-rays mirrors are possible, when the incident rays direction is almost parallel to the mirror surface. Such grazing incidence mirrors are usually coated with thin layers of precious metals like iridium, gold or platinum, as this result in high X-ray reflectivity. These noble metals offer a wide range of reflection up to high photon energies, but, due to a series of absorption edges, have low reflectivity in the 2 - 4 keV band and below. This contribution presents the development of innovative material combinations based on thin layers of iridium and chromium, followed by an additional layer of carbon-based materials. We also discuss corresponding production methods (like dip coating) for enhanced reflectivity mirror coatings of future X-ray telescopes.}, subject = {R{\"o}ntgenstrahlung}, language = {en} } @inproceedings{DoehringGoeslingPribullaetal.2019, author = {D{\"o}hring, Thorsten and G{\"o}sling, Lukas and Pribulla, Theodor and Komzik, Richard}, title = {Segmentierte Infrarotfilter f{\"u}r das {\O}1.3m Teleskop im slowakischen Tatra-Gebirge}, series = {DGaO-Proceedings}, volume = {2019}, booktitle = {DGaO-Proceedings}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2019}, abstract = {Im bayerisch-slowakischen Kooperationsprojekt SLOBATCO werden neuartige astronomische Filter entwickelt, welche auf die atmosph{\"a}rischen Transmissionsfenster im NIR Spektralbereich ausgelegt sind. Um ein aufwendiges Filterrad f{\"u}r die bei tiefen Temperaturen betriebene CCD-Kamera zu vermeiden, werden die Beobachtungen {\"u}ber eine segmentierte Filterkombination realisiert.}, subject = {Infrarot-Spektrum}, language = {de} } @inproceedings{PfenningDoehringMoeckel2019, author = {Pfenning, Stefan and D{\"o}hring, Thorsten and M{\"o}ckel, Michael}, title = {Einzelphotonenquellen - Schl{\"u}sselkomponenten f{\"u}r die Quantenwelt}, series = {DGaO-Proceedings}, volume = {2019}, booktitle = {DGaO-Proceedings}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2019}, abstract = {Deutschland investiert stark in Quantentechnologien und m{\"o}chte seine aktuelle Vorreiterrolle in diesem Markt behaupten. Einzelphotonenquellen werden als Schl{\"u}sselkomponenten vieler Quantentechnologien dabei zuk{\"u}nftig große Bedeutung erlangen. Dieser Beitrag gibt als Markt- und Technologiestudie einen {\"U}berblick {\"u}ber diese junge Hochtechnologiebranche.}, subject = {Einzelphotonenemission}, language = {de} } @inproceedings{HudecPinaInnemanetal.2019, author = {Hudec, Rene and Pina, Ladislav and Inneman, Adolf and Semencova, Veronika and D{\"o}hring, Thorsten}, title = {X/EUV and UV optics for miniature cubesats payloads}, series = {DGaO-Proceedings}, volume = {2019}, booktitle = {DGaO-Proceedings}, publisher = {DGaO}, organization = {CVUT Prag}, issn = {1614-8436}, pages = {1 -- 1}, year = {2019}, abstract = {The recent progress in cubesat technologies allows scientific payloads for these minisatellites to be considered. We will discuss the possible miniature X/EUV and UV telescopes and monitors as potential minisats payloads. The advanced electronics image detectors allows the size of the optics to be miniaturized, still providing valuable scientific results.}, subject = {Kleinsatellit}, language = {en} } @misc{SpeitWolffDoehring2019, author = {Speit, Burkard and Wolff, Silke and D{\"o}hring, Thorsten}, title = {LEAD-CONTAINING RADIATION-RESISTANT GLASS AND PRODUCTION THEREOF}, year = {2019}, abstract = {PROBLEM TO BE SOLVED: To provide an optical glass which is used for design of space-saving and light imaging optical elements provided with various glass-type lenses and used in flights of various objects in space and has an increased refractive index. SOLUTION: A glass for space comprises 5-65 wt.\% of SiO, 0-40 wt.\% of BO, 0-12 wt.\% of AlO, 5-50 wt.\% of PbO, 0-8 wt.\% of NaO and 0-20 wt.\% of KO and contains at least three doping agents selected from CeO, MoO, BiO, WO, AgO, SnO, SbOand AsOin a total content of the doping agents of at least 0.1 wt.\% in the glass for space. The glass for space preferably contains 0.5-1 wt.\% of TiO additionally.}, subject = {Optisches Glas}, language = {mul} } @inproceedings{StehlikovaDoehringSchaeferetal.2019, author = {Stehlikova, Veronika and D{\"o}hring, Thorsten and Sch{\"a}fer, Tobias and Stollenwerk, Manfred and Friedrich, Peter and Burwitz, Vadim and Hartner, Gisela and Bradshaw, Miranda and Liao, Yingyu and Pelliciari, Carlo}, title = {X-ray reflectivity measurements at chromium-iridium tri-layer coatings}, series = {Proceedings of SPIE}, volume = {2019}, booktitle = {Proceedings of SPIE}, number = {11119}, organization = {Max-Planck-Institut f{\"u}r Extraterrestrische Physik}, doi = {http://dx.doi.org/10.1117/12.2530439}, pages = {111191L-1 -- 111191L-6}, year = {2019}, abstract = {Studying astronomical objects in the X-ray regime, iridium-based layer systems are highly effective reflective materials for telescopes mirrors. Aschaffenburg University and the Czech Technical University in Prague jointly developed stress compensated chromium-iridium coatings. To overcome the disturbing reflectivity reduction of the iridium absorption edge around 2 keV photon energy and improve general reflectivity at lower incident energies, thin overcoat layers of chromium have been applied in addition. Corresponding measurements at several X-ray lines have been performed on these samples at the PANTER test facility of the Max-Planck Institute for extraterrestrial Physics. A part of the experimental results and their comparison with theoretical simulations are presented in this contribution.}, subject = {R{\"o}ntgenastronomie}, language = {en} } @article{DoehringStiehlerBoeweringetal.1994, author = {D{\"o}hring, Thorsten and Stiehler, Johannes and B{\"o}wering, Norbert and Heinzmann, Ulrich}, title = {Soft x-ray spectrum of a laser-produced gallium plasma}, series = {Journal of Physics B Atomic Molecular and Optical Physics}, volume = {27}, journal = {Journal of Physics B Atomic Molecular and Optical Physics}, number = {October}, pages = {L663 -- L669}, year = {1994}, subject = {R{\"o}ntgenspektrum}, language = {en} } @inproceedings{DoehringKoefferleinPayeretal.1994, author = {D{\"o}hring, Thorsten and K{\"o}fferlein, Matthias and Payer, Hans D. and Seidlitz, Harald K. and Thiel, Stephan}, title = {Simulation von Globalstrahlung in Expositionskammern}, series = {Umwelteinfl{\"u}sse - erfassen, simulieren, bewerten", Tagungsband der 23. Jahrestagung der Gesellschaft f{\"u}r Umweltsimulation, 09.-11. M{\"a}rz 1994, Pfinztal/Karlsruhe}, booktitle = {Umwelteinfl{\"u}sse - erfassen, simulieren, bewerten", Tagungsband der 23. Jahrestagung der Gesellschaft f{\"u}r Umweltsimulation, 09.-11. M{\"a}rz 1994, Pfinztal/Karlsruhe}, pages = {257 -- 269}, year = {1994}, subject = {Globalstrahlung}, language = {de} } @article{KloidtStockKleinebergetal.1993, author = {Kloidt, Andreas and Stock, Hans-J{\"u}rgen and Kleineberg, Ulf and D{\"o}hring, Thorsten and Pr{\"o}pper, Michael and Schmiedeskamp, Bernt and Heinzmann, Ulrich}, title = {Smoothing of interfaces in ultrathin Mo-Si multilayers by ion bombardment}, series = {Thin Solid Films}, volume = {228}, journal = {Thin Solid Films}, number = {1-2}, pages = {154 -- 157}, year = {1993}, subject = {D{\"u}nne Schicht}, language = {en} }