Problem We Solve: One of the crucial elements of any scientific installation, especially in particle accelerators and laser ignition facilities, is the timing system.

Timing systems are used for providing synchronized, accurate time to all the elements of the facility as well as for the generation of discrete triggering events and periodic signals needed by the various elements. In addition, it also can be used for radio frequency dissemination across the whole facility.

This timing system architecture is currently under development by Safran for the distribution of synchronized triggers. The system allows total flexibility when configuring the triggers in terms of direction, number of pulses, pulse rate, pulse period and delay.

Why It Is Important: Facilities are increasingly demanding better performance. Safran´s timing system is intended to achieve high precision triggers with resolutions in the order of 5ps.

How We Solve It: Our timing system is based on the following main elements:

1. Low jitter master oscillator with the possibility of integration with GNSS receivers for alignment to UTC(k) scales and resiliency options for high availability systems.
2. Time transfer and low jitter frequency dissemination based on White-Rabbit switches. Thanks to using Ethernet technology, the same timing network can be used for any kind of data distribution using the same White-Rabbit network. The solution is scalable to thousands of nodes over many kilometers.
3. End nodes including multiples interfaces for better interoperability.

Performance test/results:

Picoseconds accuracy

High accuracy signals can be generated with a delay of 3-15 picoseconds to 1.8 nanoseconds compared to a reference PPS signal. The images below show a reference signal (blue) and another one delayed an amount of picoseconds (yellow).

SETUP

Sub-nanosecond synchronization

The timing system integrates our HATI IP core, allowing for sub-nanosecond synchronization between a master (WR-ZEN) and several slave devices.

The delay between PPS signals displayed in the image is maintained over time and can be calibrated to compensate for cable delays.

The capture is continuous to ensure that the jitter of the signals is visible if it is significant.

Why Choose Us: Our timing system is based on White-Rabbit / IEEE-1588. Other solutions that bring precise timing and synchronization already exist in the market, but most of them are limited in performance or flexibility or they use complex ad-hoc elements with poor support or availability. We believe that White Rabbit protocol is the best long-term investment thanks to the following features:

• The WR devices are powered by FPGAs, therefore their hardware can be easily reprogrammed to remain up to date.
• The WR protocol was conceived by CERN, one of the best scientific institutions in the domain of research, and it actively collaborates in the design of the OHWR products we manufacture.
• All the elements in the White Rabbit solution are designed to be as modular as possible in order to reduce the cost of maintenance and upgrade.
• It allows a hybrid network: the WR Switch can be used as a normal switch to connect directly to your PC in order to be quickly linked in the network. If you do not need the specific features of the WR protocol, you do not need to use a specific network card. You can also use only the PTP features of the WR devices if you only need microsecond accuracy.
• The WR devices are compliant with the IEEE-1588-2019 High Accuracy profile. By simply firmware upgrade you can use a fully standardized device, avoiding interoperability issues and granting future upgrades.
• Safran offers a full product ecosystem, including modular devices based on the ZEN family and low-cost equipment such as LEN. Control and diagnostics devices like LLRF and BPM can be easily integrated. Thanks to our engineering team and our support capabilities, we can help you to deploy and customize the network, achieving the best timing system for your facility.