Characterization of the x-ray beam at PANTER

The PANTER x-ray test facility of Max Planck Institute for Extraterrestrial Physics is used for calibrating x-ray optics, detectors, and telescopes from Europe and around the world. The 130m x-ray beamline is composed of a long vacuum tube (Ø 1 meter) with a point-like x-ray source on one end and a large vacuum test chamber (12-meter-long, Ø 3.5 meter) on the other end. This work describes the characterization of the x-ray source's stability, including the beam's spectral, temporal, and spatial characteristics during long extensive campaigns, such as a flight module calibration. The beam’s energy spectrum and intensity are monitored continuously with a commercial Amptek Silicon-Drift-Detector (SDD) installed inside the vacuum tube at a distance of 35 meters from the x-ray source. The x-ray optic characterization is conducted by measurements with the TRoPIC pnCCD camera, a prototype of MPE’s eROSITA cameras which is located inside the large chamber. We compare the beam measured by the TRoPIC camera and SDD throughout a long observing time and discuss the correlation of the results and the method of how to derive the beam intensity at any given point in time as measured by TRoPIC. The beam characterization in terms of x-ray source stability and spectral characteristics is performed at relevant energies in the 0.1 to 11 keV range.