MicroTCA @ XFEL

The European XFEL is controlled by 250 MicroTCA Crates.

The 3.3 km long European XFEL accelerator was designed by DESY and constructed with contributions from other European countries. 27 000 bunches per second can be generated and distributed to experiments.
About 250 MicroTCA crates are installed to control the accelerator and experiments. All fast diagnostics and the high precision controls for the more than 700 accelerating cavities are controlled by MicroTCA.

MicroTCA is a modular high performance system

  • Shelfs for 1 ... 12 AMC modules are available.
  • Many possible combinations of front (AMC) and rear (RTM) modules saves development time.
  • Wide application rage form simple digital to 10 GSPS ADC.
  • Redundant fans and power supplies are foreseen.
  • Complete remote and local management.
  • State-of-the-art high speed data transfer.
  • Excellent analog signal quality.
  • Integrated Ethernet, PCIe, colck, trigger and interlock distribution.
  • AMC: Advanced Mezzanine Card; RTM: Rear Transition Module

    A shielded rack below the XFEL acceleration modules.

    Three MicroTCA crates are visible:

  • To control the RF of 16 cavities,
  • To protect the high power couplers of 16 cavities,
  • To control the magnets and the vacuum of a section.
  • High performance backplane communication

    All backplane communication is based on differential gigabit links.

  • Ethernet to all AMCs.
  • PCIe gen 3 with 4 lanes to all 12 AMCs (3.9 G Bytes/s per slot).
  • Clocks with a star topology between AMCs and MCH.
  • Point-to-point links for FPGA direct communication between AMCs.
  • MLVDS bus lines to all AMCs used for e.g. tiggers and interlocks.
  • A MicroTCA crate with an optional backplane for rear modules

    To build very compact systems a second backplane between RTM modules can be used. This patented second backplane is fully managed like the standard front backplane. In XFEL it is used to distribute RF signals to the down converters on the RTMs. It provides a better signal stability compared to an external cable solution for high precision RF with phase jitters in the order of a few fs. Optional power supplies on the rear side can deliver additional voltages and provide more power to the RTM modules.

    The XFEL gun

    One MicroTCA system that controls the diagnostics is shown on the left.

    High performance Radio Frequency controls

    ← The front side with fiber links to the central timing and for the machine protection system, and an Ethernet cable connected to the MCH.


    The rear side of the MicroTCA crate with the cable connections to the probes and forward and reflected power signals of the cavities →



    This MicroTCA shelf controls two independent RF systems with 8 cavities each of the XFEL injector.

    MicroTCA Workshop Dec. 2019: More info

    Trademarks and Copyrights:

    MicroTCA and µTCA are trademarks of PICMG
  • DESY: Deutsches Elektronen Synchrotron, Hamburg, link
  • MicroTCA Workshop: DESY Technology Lab, Hamburg, link
  • XFEL: DESY Site    European XFEL Site
  • Fotos and drawings by Kay Rehlich, 3D crate by Elma Electronic GmbH, MicroTCA Workshop by TechLab