The data acquisition card for the Large Pixel Detector at the European-XFEL

The Front End Module (FEM) is a custom on-detector FPGA based digital data acquisition card for the Large Pixel Detector (LPD) currently under construction for the European X-ray Free Electron Laser (Eu-XFEL) facility in Hamburg. The data acquisition systems at the Eu-XFEL facility will have to cope with beam timing and data rates comparable to those in particle physics experiments and employs similar components and techniques. The prototype Large Pixel Detector under construction at the STFC Rutherford Appleton Laboratory contains one Megapixel sensor elements and is constructed out of 16 identical supermodules. A FEM card is mounted on the rear of each supermodule and provides readout and control functions. Each FEM is linked to the central data acquisition by a 10 Gbps optical fibre data link running 10Gb UDP/IP protocols. In normal operation the LPD detector will generate 10 GBytes/sec of processed data for every one Megapixel of sensor area. This paper describes the design of the FEM and experience with the first prototype cards.