XFEL is an X-ray laser, which is currently under construction at DESY in Hamburg. It generates ultra-short laser flashes with a luminosity that is billions of times higher than that of the best current X-ray sources. With these flashes one can decipher the atomic details of viruses and cells, make three-dimensional images of the nano-cosmos, film chemical reactions and processes such as those inside of planets. More ...
XFEL Video, X-Ray Flash Creation (© DESY 2000):
XFEL will use 2-D sensors for image acquisition initially with 1M pixel, higher resolutions are planned for later. For one of these sensors - the DSSC (DEPFET sensor with signal compression) - our research group is developong the FPGA-based readout system. An I/O module located close to the detector receives the data from 16-detector ASICs - according to 1/16 of the detector - each over a 400 Mbit/s differential lines and combines them into four high-speed serial channels (3 Gbit/s). Due to lack of return lines at this point a protocol with forward error correction (FEC) has to be used. These high-speed data are received in a remote DAQ module and converted to 10Gb Ethernet UDP. This module is also responsible for communication with the global clock and control system and for the configuration of the sub-detector. In a separate train-builder unit, the 16 UDP channels are combined into full images and sent to the PC farm of the DAQ system.
Due to the limitations on space and power particularly the I/O module requires special optimizations.