A real-time calibration method based on time-to-digital converter for accelerator timing system

摘要: The high-intensity heavy-ion accelerator facility (HIAF) is a scientific research facility complex composed of
multiple cascade accelerators of different types, which pose a scheduling problem for devices distributed over
a certain range of 2 km, involving over a hundred devices. The White Rabbit (WR), a technology-enhancing
Gigabit Ethernet, has shown the capability of scheduling distributed timing devices but still faces the challenge
of obtaining real-time synchronization calibration parameters with high precision. This study presents a calibra#2;
tion system based on a time-to-digital converter implemented on an ARM-based System-on-Chip (SoC). The
system consists of four multi-sample delay lines, a bubble-proof encoder, an edge controller for managing data
from different channels, and a highly effective calibration module that benefits from the SoC architecture. The
performance was evaluated with an average RMS precision of 5.51 ps by measuring the time intervals from 0
to 24000 ps with 120000 data for every test. The design presented in this study refines the calibration precision
of the HIAF timing system. This eliminates the errors caused by manual calibration without efficiency loss and
provides data support for fault diagnosis. It can also be easily tailored or ported to other devices for specific
applications and provides more space for developing timing systems for particle accelerators, such as white
rabbits on HIAF.