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 -