Update on KSTAR, a pilot device for ITER
Myeun Kwon is the director of the KSTAR Research Centre located at the National Fusion Research Institute in Daejon, South Korea. KSTAR—short for Korea Superconducting Tokamak Advanced Research—is one of the first research tokamaks in the world equipped with fully superconducting magnets. We spoke with Myeun Kwon, responsible for the overall KSTAR program, about the current work and plans for the near future of the project.
ITER: What is the current status of KSTAR?
Kwon: KSTAR successfully finished its first campaign last year and we have just started the second campaign. Unlike conventional tokamaks, plasma operation in KSTAR requires longer preparation sequences, notably for the cool-down of all superconducting magnets. ITER will require similar steps. We are trying to set up a reference sequence for a full superconducting fusion device and hope to contribute to ITER operation in this way.
This year, we reached two important milestones in KSTAR: operation at full toroidal field with 3.5 Tesla and electron cyclotron heating (ECH) pre-ionization at the fundamental harmonic frequency. We upgraded the capabilities of toroidal and poloidal field power supplies, covered the inboard sector of the vacuum vessel with carbon tiles, and added more diagnostics such as the X-ray crystal spectrometer, a bolometer and soft X-ray arrays. We are currently pumping down the vacuum vessel and the cryostat with baking until late August and we will start the cool-down for the whole cold mass in September.
ITER: What are the plans for the near future? What is the R&D program?
Kwon: Korea will host the next IAEA Fusion Energy Conference in 2010, and we intend to demonstrate the readiness of KSTAR as an important fusion research device for the exploration of new operation regimes. Our first project is naturally the installation and the strengthening of the heating systems and in-vessel components. Early next year, the first Neutral Beam line will be installed and possibly the first 5 GHz lower hybrid current drive (LHCD) system as well. Most of the in-vessel components including the passive stabilizers, divertor, and in-vessel control coils will also be in place before the third campaign. A few important diagnostics will also be ready for the third campaign, including Thomson scattering and the electron cyclotron emission imaging system. All of these activities will allow us to explore shaping and vertical position control, the characterization of diverted plasmas, neutral-beam-heated and lower hybrid current-driven plasmas and hopefully the very first attempt at H-mode plasma production. We could then enter a phase of long-pulse operation and ITER-relevant modes, in parallel with the gradual upgrade of heating and current drive systems.
ITER: Has the inauguration of KSTAR and Korea's participation in ITER raised awareness about fusion research in Korea?
Kwon: Yes, indeed. Both of these events dramatically increased the awareness of the public on this issue; we saw an increase of coverage in the mass-media, an increase in the number of visitors to the Institute, and an increase in inquiries for lectures and articles. The successful commissioning of KSTAR was a final milestone after eleven years of construction, and a good example of a successful large Korean science project that reflected well on the whole of the science and engineering communities. Success in KSTAR and participation in ITER influenced public policy on fusion energy development and increased allocated resources to this green technology.
ITER: ITER and KSTAR have signed a collaboration agreement. What does that mean?
Kwon: The mission statement of KSTAR clearly states that KSTAR shall be utilized to enhance current knowledge on fusion plasmas using tokamaks and shall contribute to building a knowledge database for future superconducting devices including ITER. Although the scale and detailed design differ, there are still a lot of similarities that can provide opportunities for KSTAR to be utilized as a pilot device for ITER.
For example, KSTAR is the first fusion device to use EPICS control system software. As ITER will also be using EPICS, our experience will be very beneficial to the development of the ITER CODAC system. Also, characteristics of the KSTAR superconducting magnet and cryogenic systems could also provide valuable data to the design and operation of ITER in terms of quality control and assurance mechanisms on fabrication and assembly of important components. KSTAR will be utilized as a test bed for the 170 GHz gyrotron and the 5 GHz klystron for the electron cyclotron heating and the lower hybrid current drive respectively. This kind of collaboration will provide mutual benefits to both.
ITER: What are the plans for long-term fusion research in Korea?
Kwon: Korea's long-term plan is directed toward the development of a commercial fusion power plant for the 2040s. During this endeavour, the key strategy is to integrate KSTAR and ITER projects efficiently for DEMO and to actively participate in international activities. A planning activity has been done to assess the resources required, to develop a way to efficiently integrate results from KSTAR and ITER, to establish a basic science program relevant to fusion research to train young scientists and engineers, and to utilize the existing world-class nuclear industrial technology and man-power for fusion energy development.