A Pico-Second Stable Clock and Trigger Distribution System for the European XFEL
K.Rehlich (DESY) A.Hidvegi, C.Bohm, C.Bohm* (Stockholm University Department of Physics)
For the operation of the European X-Ray Free Electron Laser (XFEL), a system wide synchronous low-jitter clock and precise, adjustable triggers must be generated and distributed throughout the 3.5 km long facility. Consumers are numerous diagnostics, controls, and experiments. Fast ADCs require the jitter of a distributed 1.3GHz clock to be in the order of a few pico seconds (RMS) and synchronized to the accelerating RF. Due to cable lengths, and the temperature dependence of the propagation speed, temperature drifts are a serious issue. Therefore a complex monitoring and compensation mechanism has been developed to minimize these effects. The hardware platform of the XFEL will be based on the new standard µTCA and ATCA. Therefore the timing is implemented as a AMC (Advanced Mezzanine Card) module that fits into both crate systems. A prototype of this new clock and trigger system has been developed and first measurements have shown, that the strong requirements can be fulfilled.