Prof. Hyeon K. Park (Korea, Republic of)
A variety of helical structures such as dual or multiple flux tubes, distinct from the normal m=1 internal kink, are commonly observed in sawtoothing plasmas in the KSTAR tokamak assisted by electron cyclotron heating (ECH). Detailed 2D and quasi-3D images have shown that the dual flux tubes have m/n=1/1 helicity, co-rotate around the magnetic axis, and later merge into a single m=1 mode prior to the crash. Similar evolution is observed for the cases of triple or more flux tubes, where the mode helicity is ambiguous. A strong correlation has been found between the ECH position and the mode structure. A reduced MHD simulation code with a heuristic current source model has been developed to understand this correlation. Work supported by NRF Korea under grant no. NRF-2009-0082507 and U.S. DoE under contract No. DE-FG-02-99ER54531.
|Country or International Organisation||Korea, Republic of|
Prof. Gunsu YUN (Pohang University of Science and Technology)
Dr Andreas Bierwage (Japan Atomic Energy Agency) Dr Calvin Domier (University of California, Davis) Mr Gyueng-Hyuen Choe (Pohang University of Science and Technology) Prof. Hyeon K. Park (Korea, Republic of) Mr Minjun Choi (Pohang University of Science and Technology) Prof. Neville Luhmann, Jr. (University of California, Davis) Dr Siwoo Yoon (National Fusion Research Institute) Dr Woochang Lee (POSTECH) Mr Yoonbum Nam (Pohang University of Science and Technology)