TY - CHAP A1 - Ghigo, Mauro A1 - Citterio, Oberto A1 - Mazzoleni, Francesco A1 - Pareschi, Giovanni A1 - Aschenbach, Bernd A1 - Bräuninger, Heinrich W. A1 - Friedrich, Peter A1 - Hasinger, Günther A1 - Döhring, Thorsten A1 - Esemann, Hauke A1 - Jedamzik, Ralf A1 - Hölzel, Eva A1 - Parodi, Giancarlo T1 - The manufacturing of the XEUS x-ray glass segmented mirrors: status of the investigation and last results T2 - Proceedings of SPIE KW - Spiegelteleskop Y1 - 2004 VL - 5168 SP - 180 EP - 195 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 - 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 - Rivolta, Giocomo A1 - Basso, Stefano A1 - Civitani, Marta 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 -