Author: Lee, T.G.
Paper Title Page
TUCAUST05 New Development of EPICS-based Data Acquisition System for Millimeter-wave Interferometer in KSTAR Tokamak 577
  • T.G. Lee, Y.U. Nam, M.K. Park
    NFRI, Daejon, Republic of Korea
  After achievement of first plasma in 2008, Korea Superconducting Tokamak Advanced Research (KSTAR) is going to be performed in the 4nd campaign in 2011. During the campaigns, many diagnostic devices have been installed for measuring the various plasma properties in the KSTAR tokamak. From the first campaign, a data acquisition system of Millimeter-wave interferometer (MMWI) has been operated to measure the plasma electron density. The DAQ system at the beginning was developed for three different diagnostics having similar channel characteristics with a VME-form factor housing three digitizers in Linux OS platform; MMWI, H-alpha and ECE radiometer. However, this configuration made some limitations in operation although it had an advantage in hardware utilization. It caused unnecessarily increasing data acquired from the other diagnostics when one of them operated at higher frequency. Moreover, faults in a digitizer led to failure in data acquisition of the other diagnostics. In order to overcome these weak points, a new MMWI DAQ system is under development with a PXI-form factor in Linux OS platform and main control application is going to be developed based on EPICS framework like other control systems installed in KSTAR. It also includes MDSplus interface for the pulse-based archiving of experimental data. Main advantages of the new MMWI DAQ system besides solving the described problems are capabilities of calculating plasma electron density during plasma shot and display it in run-time. By this the data can be provided to users immediately after archiving in MDSplus DB.  
slides icon Slides TUCAUST05 [1.724 MB]  
Comparative Evaluation of IEEE-1588 Precision Time Protocol for the Synchronized Operation of Tokamak Device  
  • M.K. Park, S. Lee, T.G. Lee, W.R. Lee, S.W. Yun
    NFRI, Daejon, Republic of Korea
  Funding: The Korean Ministry of Education, Science and Technology
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.
poster icon Poster WEPMS012 [3.147 MB]