Martin Bruckner and Ralf Wischnewski from DESY has presented at the 33rd International Cosmic Ray Conference (ICRC2013) several articles describing a White Rabbit setup used for the HiSCORE-Tunka detector. This HiSCORE detector, a new non-imaging wide-angle Air-Cherenkov ground based array, is currently in its engineering phase. Time synchronization to nsec-level between detector stations, distributed over 10-100km2, is essential to reach best angular resolution for high energy gamma rays.

Some quotes from the three articles:

• A White Rabbit setup for sub-nsec synchronization, timestamping and time calibration in large scale astroparticle physics experiments (July 2013)
  • The big, active and very communicative WRcommunity has made the White Rabbit system a well debugged and calibrated system. In particular, for high demands on longterm precision and stability, the extensive usage and debugging of the WR-key components make it very reliable.
  • We conclude, that this White Rabbit system is ready to be applied under field conditions in large-scale astroparticle physics experiments - for time synchronization with nanosecond precision between individual detectors, distributed over km-scale.
  • We acknowledge very helpful discussions, technical advices and support from the White Rabbit community (in particular the CERN based team and A. Rubini) during all phases of this project. The technical support from both SevenSolutions and Creotech [companies- ED] was very helpful.
• Results from the WhiteRabbit sub-nsec time synchronization setup at HiSCORE-Tunka (July 2013)
  • We mention that the White architecture guarantees that the clocks in each WR-node is synchronized with full precision at any time. This is an essential difference compared to most proprietary time-synchronization solutions in experiments, based on corrections applied offline (or with significant delay).
  • We note the excellent system reliability: not a single component of four complete stations showed a failure over 6 months of Siberian winter performance (at operation/storage temperatures of 0…+30C / -45…+10C, respectively).
• Status of the HiSCORE experiment (July 2013)
  • …we trigger and read out … with waveform sampling at 1 GHz, and time-synchronization at sub-ns level with a White-Rabbit (WR) based system (time stamping and triggering). Waveform sampling and time-stamping proved to be very stable. The ns-trigger timestamps, obtained from the timing system allow clear Cerenkov air-shower detection.