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 - 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 -