Novel carbon nanotube-based foils have recently emerged in the semicon industry. These filters offer a promising path to producing high performance light blocking filters for x-ray instrumentation applications.In this activity, the technology shall be developed and demonstrators for the 2 instruments onboard ATHENA shall be produced.

As required for the ATHENA mission, filters with high opacity for IR/Visible/UV light need to be developed to reduce the straylight in these spectra. At the same time, a high transmission in the x-ray band shall be maintained.The experience from recent developments in the semicon industry of producing suitable large size carbon nanotube-based foils, shall be utilized. These foils shall form the support membrane for the required x-ray filters. Alternative paths to close the porous structure of these foils shall be identified and explored.Suitable test filters shall be produced and evaluated allowing a down-selection of the most promising implementation architecture and production method.In the following phase, demonstrators for filters as required for ATHENA, shall be produced.The resulting filters shall be characterized with regards to their performance (x-ray transmission, blocking characteristics in the other bands, environmental compatibility).