WEPMS012
NFRI, Daejon, Republic of Korea
Recently the International Thermonuclear Experimental Reactor (ITER), which is the largest project in scale to construct a fusion reactor for the research of fusion energy source jointly with seven participants, has chosen IEEE-1588 precision time protocol (PTP) as a timing system standard for precisely synchronizing tokamak operation and plasma experiments. The IEEE-1588 PTP was designed as a standard for precision clock synchronization protocol for network measurements and control systems, and guarantees higher accuracy (less than sub-microsecond) than using NTP and more economical implementation than using GPS. Besides the original purpose, the uses are expanding to the provision of event timing and synchronization capabilities for large experimental facilities like ITER. On the other hands, many working tokamaks have operated with own timing systems having non-standard protocols. The Korea Superconducting Tokamak Advanced Research (KSTAR) has successfully operated the home-made timing system with the following features; PMC foam-factor with PCI/PCI-X interface, using EPICS 3.14.12 framework, board driver in VxWork5.5.1 and Linux2.6.x platforms, a master clock of 200MHz, timing accuracy less than 50ns, 8 output ports for trigger or clock signals, 8 configurable multi-triggering sections and provision of accurate time referenced to GPS time. This paper describes the result of evaluating IEEE-1588 PTP for tokamak and its detail implementation, and also the comparative analysis with KSTAR timing system after operating them in KSTAR during the 4th campaign in 2011.
