The latest X-IFU response matrices produced by Didier Barret/Edoardo Cucchetti (IRAP) and verified by the Bamberg group led by Joern Wilms, with the support of the system team, including Philippe Peille. These files have been produced for the so-called Athena cost-constrained configuration, with a diameter corresponding to a peak effective area at 1 keV of ~1.4 square meters. The response files cover 50 eV to 12.5 keV but the usual range for the fits should be 0.2-12 keV. Please check the FITs headers to see the assumptions used. Check also the README file, and look at the PDF files. Further information can be found in the SPIE papers: Barret et al. (SPIE, 2018).
Please contact directly Didier Barret for any enquiries.