A setup for soft proton scattering on x-ray mirrors

Protons with energies between tens of keV and some MeV can degrade the performance of X-ray detectors and contribute to the instrument background. In-orbit measurements showed that the flux of soft protons funneled through Wolter-type mirrors is considerably larger than expected from simulations. Up to now, just very few results from laboratory experiments have been reported and the data is not sufficient to pinpoint the best analytical description of the physical process or to validate simulation codes. In order to improve this situation, a small angle scattering experiment to measure the proton reflection properties of X-ray mirrors has been set up at the accelerator facility of the University of Tubingen. The experimental setup and initial preliminary results obtained with samples of eROSITA mirror shells are presented.