Solitary perturbations in the steep boundary of magnetized toroidal plasma.
Solitary perturbations (SPs) localized both poloidally and radially are detected within ~100 μs before the partial collapse of the high pressure gradient boundary region (called pedestal) of magnetized toroidal plasma in the KSTAR tokamak device. The SP develops with a low toroidal mode number (typically unity) in the pedestal ingrained with quasi-stable edge-localized mode (QSM) which commonly appears during the inter-collapse period. The SPs have smaller mode pitch and different (often opposite) rotation velocity compared to the QSMs. Similar solitary perturbations are also frequently observed before the onset of complete pedestal collapse, suggesting a strong connection between the SP generation and the pedestal collapse.
Pohang University of Science and Technology, Pohang 790-784, Korea.
J E
JE
Lee
Pohang University of Science and Technology, Pohang 790-784, Korea.
G S
GS
Yun
National Fusion Research Institute, Daejeon 34133, Korea.
W
W
Lee
Pohang University of Science and Technology, Pohang 790-784, Korea.
M H
MH
Kim
National Fusion Research Institute, Daejeon 34133, Korea.
M
M
Choi
Ulsan National Institute of Science and Technology, Ulsan 689-798, Korea.
J
J
Lee
Ulsan National Institute of Science and Technology, Ulsan 689-798, Korea.
M
M
Kim
National Fusion Research Institute, Daejeon 34133, Korea.|Ulsan National Institute of Science and Technology, Ulsan 689-798, Korea.
H K
HK
Park
National Fusion Research Institute, Daejeon 34133, Korea.
J G
JG
Bak
National Fusion Research Institute, Daejeon 34133, Korea.
W H
WH
Ko
Columbia University, New York, New York 10027, USA.
Y S
YS
Park