Influence of a carbon over-coat on the X-ray reflectance of XEUS mirrors
Abstract
We describe measurements of the X-ray reflectance in the range 2-10 keV of samples representative of coated silicon wafers that are proposed for the fabrication of the X-ray evolving universe spectrometer (XEUS) mission. We compare the reflectance of silicon samples coated with bare Pt, with that for samples with an additional 10 nm thick carbon over-coating. We demonstrate a significant improvement in reflectance in the energy range ∼1-4 keV, and at a grazing incidence angle of 10 mrad (0.57°). We consider the resulting effective area that could be attained with an optimized design of the XEUS telescope. Typically an improvement of 10-60% in effective area, depending on photon energy, can be achieved using the carbon overcoat.
- Publication:
-
Optics Communications
- Pub Date:
- November 2007
- DOI:
- 10.1016/j.optcom.2007.06.049
- arXiv:
- arXiv:0707.2490
- Bibcode:
- 2007OptCo.279..101L
- Keywords:
-
- Astrophysics
- E-Print:
- 7 pages, 5 separate figures Accepted Optics Communications