The HETG has been measured together with the HRC-I between 1.45 and 7 keV at individual energies rather than in a real scan. This has been done primarily for saving total integration time and preventing the detector from being overilluminated on one position because it couldn't be moved during scans. The energies have been chosen according to the edges and features. Most of the energies are also used for HRC alone and the LETG-HRC-S combination.

The data were taken out of focus by 15 - 25 mm. The ring focus is separated for higher orders into shell 1,3 (covered by MEG) and 4,6 (for HEG) because the dispersion is titlted by +/- 5° for both gratings. At the highest energies, the outermost shell has almost no reflectivity. Therefore, the MEG-spectrum appears to be much weaker than the HEG-spectrum. Towards lower energies, the MEG becomes more and more dominant. The degapping of the images is not perfect; this would require additional effort. (Text and image courtesy, Gisela Hartner and Peter Predehl, MPE.