TY - CHAP A1 - Döhring, Thorsten A1 - Stadtmüller, Johannes A1 - Stollenwerk, Manfred A1 - Cotroneo, Vincenzo A1 - Pareschi, Giovanni A1 - Gibertini, Eugenio A1 - Magagnin, Luca T1 - Low-density coatings for enhanced X-ray reflectivity of astronomical telescope mirrors T2 - DGaO Proceedings N2 - 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. KW - Dopamin KW - Iridium KW - mirror KW - coating KW - X-ray KW - Röntgenteleskop Y1 - 2021 UR - https://www.dgao-proceedings.de/download/122/122_p3.pdf SN - 1614-8436 VL - 2021 IS - 122 SP - 1 EP - 2 PB - DGaO ER - TY - GEN A1 - Döhring, Thorsten A1 - Stadtmüller, Johannes A1 - Stollenwerk, Manfred A1 - Cotroneo, Vincenzo A1 - Pareschi, Giovanni A1 - Gibertini, Eugenio A1 - Magagnin, Luca T1 - Low-density coatings for enhanced X-ray reflectivity of astronomical telescope mirrors T2 - DGaO Jahrestagung N2 - 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. N2 - Poster KW - X-ray KW - mirror KW - coating KW - iridium KW - satellite KW - Röntgenstrahlung KW - Spiegelteleskop Y1 - 2021 UR - https://dgao.de/jahrestagung/ VL - 2021 SP - 1 EP - 1 ER - TY - CHAP A1 - Pareschi, Giovanni A1 - Civitani, Marta Maria A1 - Sironi, Giorgia A1 - Yang, Yang A1 - Cotroneo, Vincenzo A1 - Valsecchi, Giuseppe A1 - Magagnin, Luca A1 - Döhring, Thorsten A1 - Bradshaw, Miranda A1 - Burwitz, Vadim A1 - Pelliciari, Carlo T1 - Reflectivity-enhancement at low x-ray energies in astronomical telescopes using low-density overcoatings: alternative materials and deposition methods T2 - Proceedings of SPIE N2 - Low density overcoatings (mainly based on materials containing Carbon) onto usual high-density coatings (based i.e. on materials like e.g. like Ir, Au or Pt) have been proposed since many years ago in order to enhance the X- ray reflectivity at low energy (between 0.5 and 4 keV) of X-ray astronomical optics. The trick is to make use of the total reflection from the thin low-density material (which does not suffer much the photoelectric absorption) at low X-ray energies; the reflection of photons at higher energies (< 4 keV) occurs thanks to the much denser material under the overcoating. For several future projects, like e.g. ATHENA, LYNX and eXTP, it is foreseen the use of low-density overcoatings that will importantly increase the effective area at low X-ray energies. In this paper we will introduce the use of overcoatings based on materials different from the usual ones considered so far like C, B4C and SiC. In particular, we will discuss about a novel approach based on the use of thin layer of a Carbon-like materials deposited using a dip coating method. A possible combination with an intermediate thin layer of Chromium deposited e.g. via sputtering onto the usual high density material (Ir, Au or Pt) before the application of the Carbon-like material is also considered in the study, because it can further greatly enhance the soft X-ray effective area of future X-ray telescopes. KW - coating KW - X-ray KW - telescope KW - iridium KW - Röntgenteleskop Y1 - 2019 U6 - https://doi.org/https://doi.org/10.1117/12.2532392 VL - 2019 IS - 11119 SP - 11119OS-1 EP - 11119OS-13 PB - SPIE ER - TY - CHAP A1 - Cotroneo, Vincenzo A1 - Bruni, Ricardo A1 - Döhring, Thorsten A1 - Ferreira, Desiree A1 - Gibertini, Eugenio A1 - Henriksen, Peter A1 - Magagnin, Luca A1 - Massahi, Sonny A1 - Pareschi, Giovanni A1 - Romaine, Suzanne A1 - Sethares, Leandra A1 - Sironi, Giorgia A1 - Spiga, Daniele A1 - Tagliaferri, Gianpiero A1 - Valsecchi, Giuseppe T1 - Development of low-density coatings for soft x-ray reflectivity enhancement for ATHENA and other missions T2 - Proceedings of SPIE N2 - Metallic coatings made of precious metals (e.g. Ir, Pt or Au) with high atomic number Z have been traditionally employed at grazing incidence for X-rays reflection and focalization. These materials offer a range of reflection extended to higher energies, but also present a series of absorption edges, which limit the reflectivity in the 2-4 keV band and below. Therefore the search for alternative coatings, able to improve the reflection in the soft energy range, is particularly relevant for the development of future telescopes, like ATHENA (ESA), Lynx (NASA) and eXTP (CAS). Low-Z overcoatings (e.g. carbon or B4C), applied on top of the high-Z metallic layer, can enhance the reflectivity in the softer band (mainly below 2 keV), but conventional deposition methods for these materials are not easily compatible with some of the mainstream technologies for mirror fabrication (notably, the silicon pore optics that will be used for the ATHENA X-ray mission which is being implemented by ESA). In this work we discuss novel solutions (carbon-like overcoatings realized by dip coating or vapor phase deposition), which can be particularly convenient for the application to ATHENA and to future telescopes. KW - X-ray KW - optics KW - ATHENA KW - iridium KW - reflectivity KW - Röntgenteleskop Y1 - 2021 U6 - https://doi.org/https://doi.org/10.1117/12.2599803 VL - 2021 IS - 11852 SP - 118524P-1 EP - 118524P-13 PB - SPIE ER - TY - GEN A1 - Giovanni, Pareschi A1 - Döhring, Thorsten A1 - Valsecchi, Guiseppe A1 - Magagnin, Luca A1 - Bradshaw, Miranda A1 - Burwitz, Vadim A1 - Civitani, Marta Maria A1 - Cotroneo, Vincenzo A1 - Gibertini, Eugenio A1 - Pelliciari, Carlo A1 - Sironi, Giorgia A1 - Yang, Yang T1 - Enhancing the ATHENA effective area at low x-ray energies with unconventional overcoatings T2 - Proceedings of the X-RAY ASTRONOMY 2019 conference N2 - Low density overcoatings (mainly based on materials containing Carbon) onto usual hi Z materials (like Ir, Au or Pt) have been proposed more than 10 years ago for enhancing the X-ray reflectivity at low energy (between 0.5 and 4 keV) in X-ray astronomical optics. The hack is to use the total reflection from the low density material (which do not suffer much the photoelectric absorption) at low energy, while the photons at high energy are reflected by the high density material. Now for several future projects like e.g. ATHENA and eXTP it is foreseen the use of low density overcoatings that will importantly increase the effective area at low energy. In this poster we will discuss about the use of materials different from the ones considered so far, in particular based on a thin layer of Chromium followed by another layer of a Carbon-like material, and of novel approaches for their application. N2 - Poster KW - X-ray KW - mirror KW - coating KW - reflectivity KW - ATHENA KW - Röntgenteleskop Y1 - 2019 UR - https://indico.ict.inaf.it/event/720/contributions/5665/ VL - 2019 SP - 1 EP - 1 ER - TY - GEN A1 - Ermilova, Elena A1 - Hertwig, Andreas A1 - Döhring, Thorsten A1 - Stanik, Eva A1 - Cotroneo, Vincenzo A1 - Gibertini, Eugenio T1 - Ellipsometrische Charakterisierung von Polydopamin für funktionelle technische Schichten N2 - Obwohl das organische Molekül Dopamin (3,4-Dihydroxyphenethylamin) allgemein eher als „Glückshormon“ bekannt ist, sind dünne Schichten aus Polydopamin heute zunehmend auch für innovative technische Anwendungen von Interesse. Ein Beispiel sind reflexionsverstärkende Beschichtungen für astronomische Röntgenspiegel. Bei der Herstellung durch eine Tauchbeschichtung wachsen die selbstorganisierenden Polydopamin-Schichten in Einzel- oder Mehrfach-Moleküllagen mit reproduzierbaren Dicken von wenigen Nanometern auf. Mit der Methode der spektroskopischen Ellipsometrie wurde die dielektrische Funktion von Polydopamin vom ultravioletten bis zum nahen infraroten Spektralbereich zunächst bei Modellschichten ausreichender Dicke vermessen. Über ein optisches Modell wurden diese Daten dann zur Bestimmung der Schichtdicken deutlich dünnerer Polydopamin-Schichten verwendet. Das Ergebnis dieser Studie ermöglicht ein besseres Verständnis des Zusammenhangs von Schichtdicken und Schichteigenschaften in Abhängigkeit von den gewählten Prozessparametern. Darüber hinaus wird ein Ausblick auf potentielle weitere technische Anwendungen des interessanten bionischen Materials Polydopamin gegeben. N2 - Poster KW - Optik bei unkonventionellen Wellenlängen KW - Dünne Schichten KW - Optische Materialeigenschaften KW - Dünne Schicht KW - Röntgenastronomie Y1 - 2024 UR - https://www.dgao-proceedings.de/abstract/abstract_only.php?id=3017 ER - TY - CHAP A1 - Ermilova, Elena A1 - Hertwig, Andreas A1 - Döhring, Thorsten A1 - Stanik, Eva A1 - Cotroneo, Vincenzo A1 - Gibertini, Eugenio T1 - Ellipsometrical characterization of poly-dopamine layers considered for technical applications T2 - Proceedings of SPIE N2 - Although the organic molecule dopamine (3,4-dihydroxyphenethylamine) is commonly known as the “hormone of happiness”, thin films of poly-dopamine also have interesting technical properties. When produced by dip coating, the self-organizing layers grow in a reproducible thickness of single or multiple molecule monolayers of a few nanometer thickness only. In this work, we introduce a method of determining the layer thickness of poly-dopamine on mirrors for astronomical X-ray telescopes. This work is based on spectroscopic ellipsometry measurements and involves the development of an optical model for the poly-dopamine layers including the dielectric function. Thereby the complex refractive index of the produced layers was determined, covering the range from the ultraviolet to the near infrared spectral region. These measurement results and the corresponding technical challenges are presented in this contribution. Furthermore, an outlook to potential technical applications of this interesting material is given and poly-dopamine layers will make scientist and engineers hopefully happy as an innovative and fascinating technical solution for the future. KW - dopamine KW - ellipsometry KW - refractive index KW - thin films KW - X-ray mirror KW - Dünne Schicht KW - Dopamin KW - Ellipsometrie Y1 - 2024 UR - https://doi.org/10.1117/12.3015281 U6 - https://doi.org/https://doi.org/10.1117/12.3015281 VL - 2024 IS - 13013 SP - 1301309-1 EP - 1301309-8 ER - TY - CHAP A1 - Ermilova, Elena A1 - Hertwig, Andreas A1 - Döhring, Thorsten A1 - Stanik, Eva A1 - Cotroneo, Vincenzo A1 - Gibertini, Eugenio T1 - Ellipsometrische Charakterisierung von Polydopamin für funktionelle technische Schichten T2 - DGaO-Proceedings N2 - Dünne Schichten aus dem bionischen Material Polydopamin (PDA) sind heute zunehmend auch für innovative technische Anwendungen von Interesse. Mittels spektroskopischer Ellipsometrie wurde die dielektrische Funktion von PDA vom ultravioletten bis zum nahen infraroten Spektralbereich vermessen. Über ein Modell wurde auch die Dicke dieser selbstorganisierenden Schichten bestimmt. KW - Polydopamin KW - PDA KW - Ellipsometrie KW - Röntgenspiegeln KW - Astronomie KW - Dünne Schicht KW - Röntgenastronomie Y1 - 2024 UR - https://www.dgao-proceedings.de/download/125/125_b6.pdf VL - 2024 IS - 125 SP - 1 EP - 2 ER - TY - CHAP A1 - Rivolta, Giacomo A1 - Basso, Stefano A1 - Civitani, Marta Maria A1 - Cotroneo, Vincenzo A1 - Döhring, Thorsten A1 - Michler, Willy-Leopold A1 - Pareschi, Giovanni A1 - Spiga, Daniele A1 - Stollenwerk, Manfred T1 - Upgrade of a laboratory X-ray diffractometer to extend its operating range towards soft energies T2 - Proceedings of SPIE N2 - The optical properties of X-ray mirror samples are commonly measured using diffractometers based on laboratory sources; like the Bede D1 diffractometer operating at INAF-OAB. This instrument can generate a collimated X-ray beam up to 60 keV, even though the most interesting energy region for x-ray astronomy applications is usually below 10 keV. In the softest part of this range (below 6 keV), high X-ray absorption in air hinders a full and precise characterization of optical components. In this work, we present an upgrade of the Bede D1 diffractometer that extends the operative range of the instrument below 6 keV; this is done by maximizing the flux at lowest energies and by reducing absorption by means of a helium-rich atmosphere. The upgraded instrument will be used for the tests of X-ray mirrors with innovative soft X-ray coatings, with potential application to the next generation X-ray telescopes (such as ATHENA and eXTP). KW - X-ray KW - mirror KW - reflectivity KW - refractometer KW - ATHENA KW - Röntgenspiegel KW - Diffraktometer Y1 - 2022 UR - https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12181/121814S/Upgrade-of-a-laboratory-x-ray-diffractometer-to-extend-its/10.1117/12.2629940.short U6 - https://doi.org/doi: 10.1117/12.2629940 SN - 0277-786X VL - 2022 IS - 12181 SP - 121814S-1 EP - 121814s-7 PB - SPIE ER - TY - CHAP A1 - Cotroneo, Vincenzo A1 - Bruni, Ricardo A1 - Civitani, Marta Maria A1 - Döhring, Thorsten A1 - Gibertini, Eugenio A1 - Magagnin, Luca A1 - Pareschi, Giovanni A1 - Rivolta, Giacomo A1 - Romaine, Suzanne A1 - Sethares, Leandra A1 - Sironi, Giorgia A1 - Tagliaferri, Gianpiero A1 - Valsecchi, Giuseppe T1 - Dopamine dip-liquid overcoatings for soft X-ray reflectivity enhancement T2 - Proceedings of SPIE N2 - It has been known for some time that sputtered low-density coatings deposited under vacuum (e.g. carbon or B4C), applied on top of high-density metallic coatings, can enhance the reflectivity in the soft x-ray band (below ~5 keV). In the last years, we experimented with novel carbonated coatings obtained by dip-liquid deposition, in which a thin film is formed on the surface of a mirror by immersion in a suitable precursor solution. After several attempts with different chemical compounds, we found an optimal candidate both for the reflectivity performance and for the convenience of the deposition process, which is much simpler and inexpensive compared to conventional processes. In particular, such coatings can enhance the soft x-ray response at the reflection angles employed in future telescopes, like ATHENA (ESA), Lynx (NASA) and eXTP (CAS). In this paper we consider the application of dip-liquid overcoatings on conventional coatings (Au, Ir) or in combination with recently proposed chromium overcoatings and their possible uses to enhance the reflectivity of x-ray mirrors at low, medium or higher energies, presenting the first experimental results of x-ray tests on these coatings. KW - astronomical telescopes KW - soft x-ray KW - reflectivity enhancement KW - dopamine overcoatings KW - Röntgenspiegel KW - Röntgenteleskop Y1 - 2022 UR - https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12181/2630212/Dopamine-dip-liquid-overcoatings-for-soft-x-ray-reflectivity-enhancement/10.1117/12.2630212.short U6 - https://doi.org/10.1117/12.2630212 VL - 2022 IS - 12181 SP - 1218117 EP - 1218117 ER - TY - CHAP A1 - Rivolta, Giacomo A1 - Bruni, Ricardo A1 - Civitani, Marta Maria A1 - Cotroneo, Vincenzo A1 - Döhring, Thorsten A1 - Gibertini, Eugenio A1 - Magagnin, Luca A1 - Pareschi, Giovanni A1 - Romaine, Suzanne A1 - Sethares, Leandra A1 - Sironi, Giorgia A1 - Tagliaferri, Gianpiero A1 - Valsecchi, Giuseppe T1 - Development in carbon-based coatings for X-ray astronomy T2 - IWXM 2022, 7th International Workshop on Metrology for X-ray Optics, Mirror Design and Fabrication, Berlin, 5th - 8th April 2022 KW - x-ray astronomy KW - carbon-based coatings KW - x-ray telescopes KW - Röntgenastronomie KW - Röntgenteleskop Y1 - 2022 ER - TY - CHAP A1 - Döhring, Thorsten A1 - Stollenwerk, Manfred A1 - Stadtmüller, Johannes A1 - Zeising, Sebastian A1 - Flachs, Dennis A1 - Stehlikova, Veronika A1 - Burwitz, Vadim A1 - Krumrey, Michael K. A1 - Cotroneo, Vincenzo A1 - Klementova, Mariana T1 - Characterisation of X-ray mirrors based on chromium-iridium tri-layer coatings T2 - Proceedings of SPIE N2 - Iridium-based layer systems are highly effective mirror coatings for space-born X-ray telescopes. During the recent years, Aschaffenburg University of Applied Sciences and its partners developed stress compensated chromium-iridium coatings for such astronomical applications, using chromium as an adhesive layer between iridium reflective layer and mirror substrate. However, there was room for improvement: To overcome the disturbing reflectivity reduction of the iridium absorption edge around 2 keV photon energy, thin overcoat layers of chromium are applied in addition now. This layer system has been analyzed by atomic force microscopy and transmission electron microscopy images. Furthermore, the reflectivity of such innovative X-ray mirrors based on chromium-iridium tri-layer coatings was recently measured at PTB's four-crystal monochromator beamline at the synchrotron radiation facility BESSY II. The experimental results, obtained for photon energies between 1.9 keV and 11 keV at two grazing incidence angles (0.6 degree and 0.9 degree) and their comparison with corresponding simulations are presented in this contribution. When compared to simulations of pure iridium coatings, a significantly higher reflectivity was achieved especially in the soft X-ray regime between 2 keV and 4 keV. Such chromium-iridium tri-layer coatings have high potential to increase the effective area for X-ray telescopes in Lobster Eye Design, for Wolter-I type X-ray optics, and for silicon pore optics as considered for the ATHENA telescope of the European Space Agency. KW - iridium KW - mirror KW - X-ray KW - coating KW - telescope KW - Röntgenspiegel KW - Röntgenteleskop KW - Iridium Y1 - 2021 U6 - https://doi.org/https://doi.org/10.1117/12.2592551 VL - 2021 IS - 11776 SP - 1177607-1 EP - 11776076 PB - SPIE ER - TY - CHAP A1 - Khropost, Diana A1 - Riethmüller, Franziska A1 - Döhring, Thorsten A1 - Flachs, Dennis A1 - Hülagü, Deniz A1 - Hertwig, Andreas A1 - Cotroneo, Vincenzo A1 - Gibertini, Eugenio ED - Hudec, René ED - Pina, Ladislav T1 - Polydopamine: a bio-inspired polymer for X-ray mirror coatings and other technical applications T2 - EUV and X-ray Optics: Synergy between Laboratory and Space IX N2 - Although the organic molecule dopamine (3,4-dihydroxyphenethylamine) is commonly known as one of the “hormones of happiness”, thin polymer films of polydopamine (PDA) also have interesting technical properties. PDA is a very strong glue that sticks on almost everything, even under water. In nature, PDA is found in the byssal thread cuticles of mussels. When produced by dip-coating, the self-organizing PDA layers grow in a reproducible thickness of single or multiple molecule monolayers of a few nanometres thickness only. Here we present an optimized preparation regime as derived from polymerization analysis through absorption spectroscopy. One application is the use of thin PDA overcoatings to increase the soft X-ray reflectivity of astronomical X-ray mirrors. Furthermore, we give an outlook to other technical applications for this interesting material, presenting this bio-inspired organic polymer as an innovative technical solution for the future, with applications such as PDA-based super-capacitors and its promising role in enhancing separator materials for batteries. KW - polydopamin KW - ellipsometry KW - X-ray KW - battery KW - Röntgenspiegel KW - Beschichtung Y1 - 2025 U6 - https://doi.org/10.1117/12.3056298 VL - 2025 IS - 13531 SP - 135310H-1 EP - 135310H-11 PB - SPIE ER -