Characterization of the detection chain of the Micro-channel X-ray Telescope

This paper describes the first performance tests and characterization of the detection chain of the Micro-channel X-ray Telescope (MXT), one of the instruments on board the French-Chinese mission SVOM for the study of Gamma-Ray Bursts. The MXT detector consists of a back-illuminated 450µm-thick fully-depleted frame-store silicon pnCCD, operating in the 0.2−10keV energy range. Featuring an imaging area of ≈4cm2, the device is read out in parallel by two CAMEX ASICs and is powered and controlled by its dedicated Front-End Electronics. A complete setup based on a cryostat and a multi-energy X-ray source have been designed for the characterization of the detection chain. The tests, performed at ≈−65°C, demonstrate a spectral resolution of (82±2)eV at 1.5keV as well as a <200eV low-level threshold. Both of those results are in compliance with the performance requirements of the instrument.