X-ray imaging performance of the flight model JET-X telescope

Construction of the Flight Model Joint European X-ray Telescope (JET-X) for the Russian Spectrum-X mission has been completed and performance tests and calibration of the instrument have been carried out. Separate measurements of the responses of the X-ray mirrors, the CCD detectors and the optical filters already indicate that JET-X will achieve spatial resolutions of around 20 arcsec, an on-axis collecting area of 310cm(2) at 1.5 keV and an energy resolution of 130 eV at 6 keV. As a final step in the calibration of the telescope assembly, end-to-end X-ray tests on the complete instrument have been performed in the X-ray beam line facility at MPE Garching. Results from this calibration programme are reported and the overall response of the two X-ray telescopes are compared with the previously measured responses of the mirror, the CCD detectors and the optical filters. In-orbit sensitivity responses are derived from these calibration data sets, for the normal operating modes of JET-X.