Our x-ray window has been tested successfully at the BESSY II synchrotron source

"A good alternative is a 1 µm-thick graphenic carbon window (G1, G2) produced by KETEK for RT applications (Huebner et al., 2015). Our test showed that this window can be also used under cryo-temperatures. This graphenic carbon window has an opening of 7 mm and 90% transmission at 2 keV. We have not observed any degradation after one year of use at the PINK beamline." JOURNAL OF SYNCHROTRON RADIATION , Volume 31| Part 3| May 2024| Pages 622-634  https://doi.org/10.1107/S1600577524002200