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 copyright foto DESY/KH

The world’s fastest soft X-ray camera, called DSSC, has been successfully put in operation at the European XFEL near Hamburg - a research infrastructure than can deliver ultra-short and ultra-intense flashes of X-rays. The successful installation and qualification of this unique detector marks the culmination of more than a decade of international collaborative research and development of a group of reserarchers associated to INFN (Sections of Milano and of Pavia) in collaboration with DESY, University of Heidelberg and European XFEL. The international consortium of the DSSC partners is coordinated by Matteo Porro (European XFEL). The INFN group of Milano (Andrea Castoldi, Carlo Fiorini, Chiara Guazzoni) is with Politecnico di Milano and led the development of the analog front-end electronics and the calibration of the DSSC detector. The INFN group of Pavia (Massimo Manghisoni, Valerio Re) is with Università di Bergamo and was responsible of the tests of the individual sensor modules.

The DSSC detector (DePFET Sensor with Signal Compression), designed specifically for imaging low energy X-rays (0.5 – 6 keV), will significantly expand the scientific capabilities of the instrument for Spectroscopy and Coherent Scattering (SCS) where it is currently installed. It will enable ultrafast studies of electronic, spin and atomic structures on the time scale of few tens of femtoseconds making use of each X-ray flash provided by the European XFEL. At the end of May, the first scientific experiments were successfully conducted at the SCS instrument using the DSSC camera for the first time.

During a typical experiment, ultra-intense and ultra-short X-ray flashes hit the sample under analysis. The European XFEL can deliver up to 2700 X-ray flashes in quick succession with a time difference between two flashes of only 220 nanoseconds. The X-rays diffused by the atoms of the sample produce a distinctive pattern that is recorded and stored by the detector located behind the sample. At full capacity, the DSSC detector can acquire images at the impressive rate of 4.5 million images per second with single-photon resolution and for every train of pulses the DSSC detector can store 800 one megapixel images. This makes the DSSC the fastest soft X-ray detector in the world.