General Machine Timing System at GSI and FAIR

whiterabbit logo.png

The FAIR facility involves a long chain of accelerators which need to be tightly synchronized. This is achieved by the General Machine Timing (GMT) system, a distributed event generation system based on the notion of time. Time synchronization is achieved by using White Rabbit (WR), a fully deterministic Ethernet-based field bus for clock transfer and synchronization. The key components of the GMT are a so-called Data Master (DM) that schedules actions by broadcasting messages, a WR network and Timing Receiver (TR) nodes executing machine relevant actions on time.

The primary tasks of the timing system are the following.
  • Time-Synchronization of ~2000 - 3000 nodes with sub-ns accuracy over fiber lengths of up to 2 km.
  • Distribution of TAI counters with ns accuracy.
  • Generation of timing events for synchronization of equipment.

About...

The aim of this timing web is to provide an overview on the timing system and its relationship to other systems. Moreover, it is the central point for documentation. Please note, that the timing system is still under development.

Topics

Announcements

Please checkout this mattermost channel.

Scheduled downtime of the GMT production system as agreed with operations are marked with bold letters. Non-bold letters are activities by others are only listed for information.

  • *17-21 Oct shifted to 2023: GMT maintenance, installation of White Rabbit network distribution rack at LSB6*
    • no White Rabbit network west of TK
    • no operation of MIL Pulszentrale at UNILAC
  • 21 Nov-2 Dec 2022: control system test ('dry-run') with EL7
  • 5-6 Dec 2022: GMT maintenance, deployment of White Rabbit Switch firmware
  • 12 Dec 2022 -6 Jan 2023: no power in electric circuits EJ, DE, EC, ED, EE, SIS.Magnete (BR1-BR3, VR, EH, ...)
  • the schedule for 2023 will be posted soon

GMT-schedule.png
Figure: Schedule for the next weeks based on shutdown planning. For an overview, click here or here.

News

  • 5-7-Oct-2022
    • urgent maintenance on White Rabbit switches
  • 31-Aug-2022
    • maintenance window closed
  • 30-Aug-2022
    • maintenance window open
  • 04 July 2022
    • begin of shutdown activities
  • 30 June 2022
    • end of beam-time 2022!
  • 09 May 2022
    • user beam-time (next part)
  • 02 May 2022
    • machine experiments
  • 25 April 2022
    • beam commissioning starts
  • 19 April 2022
    • operator training ends
    • maintenance break
  • 16 April 2022
    • first part of beam time ends
    • operator training til Monday
  • 05 March 2022
    • restart Data Master
  • 01 February 2022
    • user beam-time starts!
  • 28 January 2022
    • beam commissioning starts
    • beam extracted from SIS18
  • 24 January 2022
    • maintenance window open and closed
  • 21 January 2022
    • dry-run ends
  • 17 January 2022
    • dry-run starts
  • 22 December 2021
    • more tests with 'booster mode'
    • -> good transfer timing from UNILAC to SIS18 can be achieved with an efficiency exceeding 98% (click)
  • 16 December 2021
    • maintenance window closed
  • 15 December 2021
    • maintenance window open
  • 03 December 2021
    • dry-run ends
    • we had two weeks of smooth GMT operation
  • 23 November 2021
    • booster mode
      • for the first time, the so-called booster mode has been demonstrated (dry-beam)
      • dry-beam is injected, accelerated and extracted from SIS18 with a repetition rate of 2.7 Hz
      • the key challenge is tight synchronization of SIS18 and the 50 Hz machine UNILAC at this high rate
  • 22 November 2021
    • dry-run starts
    • new handshake mechanism Data Master <-> UNILAC Pulszentrale successfully established
  • 05 November 2021
    • maintenance window closed
  • 03 November 2021
  • 01 November 2021
    • maintenance window starts (full week)
  • Older News

GSI Timing Team

-- DietrichBeck - 17 November 2022

I AttachmentSorted descending Action Size Date Who Comment
GMT-schedule.pngpng GMT-schedule.png manage 45 K 31 Aug 2022 - 08:58 DietrichBeck another plan for the next weeks ...
This topic: Timing > WebHome
Topic revision: 17 Nov 2022, DietrichBeck
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