Speaker
Description
The T2K (Tokai-to-Kamioka) is a long-baseline neutrino oscillation experiment that requires a reliable timing distribution system at the J-PARC to receive the main-ring (MR) beam-kicker timing pulse signal and broadcast beam-trigger pulse signals with spill numbers to neutrino facilities in Tokai. The existing timing distribution system, originally developed in the K2K (KEK-to-Kamioka) era more than two decades ago, increasingly suffers from component obsolescence and occasional signal dropouts. Furthermore, the upcoming Hyper-Kamiokande project will install an Intermediate Water Cherenkov Detector (IWCD) approximately 1 km from the J-PARC, and the required transmission distance around 10 km when routed through the site-wide fiber infrastructure.
We propose a timing distribution method based on timing-pulse digitization and the MIKUMARI link protocol. In the timing distribution system, a main board digitizes the MR beam-kicker timing pulse signal by an FPGA ISERDES primitive and distributes its leading-edge timestamp together with a spill number to sub boards by the MIKUMARI link protocol via optical fibers. Based on the MIKUMARI link, the main board and sub boards maintain local time counters under frequency synchronization. The sub boards at the neutrino facilities map the received timestamp to their local counters and regenerate the beam-trigger pulse at the corresponding time using FPGA OSERDES primitives. Using FPGA I/OSERDES primitives to digitize and regenerate pulse signals, the system achieves sub-clock timing resolution.
In this presentation, we will report the details of the method that can transmit the pulse signal over 10 km optical fibers with a timing variation of 1 ns.
| Minioral | Yes |
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| IEEE Member | No |
| Are you a student? | Yes |