Study on divertor plasma behavior through sweeping strike point in new lower divertor on EAST

• Published in: Chinese physics B Vol. 31; no. 6; pp. 65204 - 603
• Main Authors: Tao, Yu-Qiang, Xu, Guo-Sheng, Meng, Ling-Yi, Liang, Rui-Rong, Yu, Lin, Liu, Xiang, Yan, Ning, Yang, Qing-Quan, Lin, Xin, Wang, Liang
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.06.2022; Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China; Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,China; University of Science and Technology of China,Hefei 230026,China%Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China%Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China
• Subjects: decay length; divertor plasma; EAST tokamak; sweeping strike point; EAST tokamak; decay length; divertor plasma; sweeping strike point
• ISSN: 1674-1056
• DOI: 10.1088/1674-1056/ac4a65

A series of L-mode discharges have been conducted in the new ‘corner slot’ divertor on the Experimental Advanced Superconducting Tokamak (EAST) to study the divertor plasma behavior through sweeping strike point. The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils, with keeping the main plasma stability. The surface temperature of the divertor target cools down as the strike point moves away, indicating that sweeping strike point mitigates the heat load. To avoid the negative effect of probe tip damage, a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λ js , λ q . In the discharges with high radio-frequency (RF) heating power, electron temperature T e is lower and λ js is larger when the strike point locates on the horizontal target compared to the vertical target, probably due to the corner effect. In the Ohmic discharges, λ js , λ q are much larger compared to the discharges with high RF heating power, which may be attributed to lower edge T e .