The high-precision timing system is a complex timing control system for large particle accelerators. Each subsystem and equipment operate in a coordinated manner according to strict timing, just like the heart of the accelerator, providing high-precision synchronous trigger pulses and different frequency synchronous cyclotron clocks for its various injection equipment., providing synchronous high-frequency clocks and specific required trigger signals for data acquisition equipment, and can also provide hardware time stamp services for the entire accelerator.
The high-precision timing system adopts a distributed event publishing method, that is, the event code containing timing information is simultaneously transmitted to each receiver in the form of broadcast, and the receiver simultaneously generates trigger pulses to each device. Among them, the event generator (EVG) generates an event code that is synchronized with the high-frequency clock and the AC power grid, and transmits the event code to the event receiver (EVR) through the fan-out module (FANOUT) and optical fiber. The event receiver outputs the required delay adjustable timing pulse required by each equipment.
Since 2003, the research team has begun to pay attention to and research the domestic and foreign technological development of high-precision timing systems. From 2005 to 2007, the Shanghai Light Source Timing System was realized using commercial hardware boards and independently developed software systems. System jitter, that is, the timing jitter of the output pulse relative to the high-frequency clock, is about 21ps.
From September 2007 to December 2010, we independently developed the first generation of SINAP high-precision timing system hardware and software. We have adopted internationally advanced 2.5Gbps Fiber Channel technology, high-speed digital circuit design technology and high-end FPGA/high-speed serial-parallel transceiver technology. Based on the software structure of large-scale accelerators and experimental physics, the system wobble is 6ps, which has exceeded that of similar foreign commercial products.
From August 2011 to July 2012, the hardware structure of the system was redesigned, and the second generation of SINAP high-precision timing system hardware and software were successfully developed. Functions such as cascading of different high-frequency systems have been added; clock and synchronization implementation technologies have been changed; two-way fast data transmission functions within optical fiber networks have been added; hardware interrupt functions have been updated; and the system software structure has been improved. The system shake is 5ps, which has become the world's advanced level, and these new technologies can better meet the complex needs of particle accelerators at home and abroad.
Since May 2007, the Shanghai Light Source has been completed using foreign commercial hardware and independently developed software, providing a total of about 400 timing pulses for the linear accelerator and two synchrotrons. After the completion of the Shanghai Light Source in April 2009, the system has been running stably and has been used in China. For the first time, the application of a centralized timing system in a large-scale accelerator physics experimental device has been realized. Since July 2011, we have applied the first-generation high-precision timing system independently developed in the upgrade project of Pohang Light Source (PLS-II) in South Korea. So far, the software and hardware have been stable and recognized by South Korea. In March 2013, the software and hardware of the second-generation high-precision timing system were tested on site in the SuperKEKB linear accelerator control room, realizing synchronization of different high-frequency signals, PLC-EVR-based interrupt function, EVG interrupt function, system shaking of 5ps, etc., and can then be applied to the Japanese SuperKEKB collider renovation project. At present, South Korea's free electron laser project and nuclear waste disposal ADS project have decided to adopt high-precision timing systems; China's spallation neutron source project has also listed this system as one of the options.
These all prove that my field of fast electronics dedicated to accelerator control and beam measurement has been recognized by my foreign counterparts, and has gradually reversed the situation of domestic fast electronics equipment dedicated to accelerator control and beam measurement being dependent on imports.