A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST

Guosheng Xu, Volker Naulin, Baonian Wan, Houyang Guo, Wei Zhang, Jiafeng Chang, Ning Yan, Siye Ding, Ling Zhang, Liang Wang, Shaocheng Liu, Peng Liu, Min Jiang, Huiqian Wang, Jens Juul Rasmussen, Anders Henry Nielsen, Chijin Xiao, Xiang Gao, Liqun Hu, Sizheng Zhu & 3 others Zhenwei Wu, Jinping Qian, Xianzu Gong

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Ion's toroidal velocity, vt, in both the outermost 4 cm of the confined region and the scrap-off layer of Ohmic L-mode plasmas in EAST was measured using Mach probes. At about 1 cm inside the separatrix a local minimum in vt was observed, from which a cocurrent rotation increased both inwards and outwards. The radial width of the vt dip was 1 cm to 2 cm, and both the density and electron temperature profiles exhibited steep gradients at this dip position. It was observed in both divertor and limiter configurations. To find out its origin, the toroidal torques induced by neutral friction, neoclassical viscosity, collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress were estimated using the measured parameters. Our results indicate that in this particular parameter regime the neutral friction was the dominant damping force. The calculated cocurrent toroidal torque by the neoclassical viscosity dominates over those from the collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress. These results are potentially important for the understanding of boundary conditions for the intrinsic toroidal momentum in tokamak plasmas.
    Original languageEnglish
    JournalPlasma Science and Technology
    Volume13
    Issue number4
    Pages (from-to)397-404
    ISSN1009-0630
    DOIs
    Publication statusPublished - 2011

    Keywords

    • Fusion energy

    Cite this

    Xu, Guosheng ; Naulin, Volker ; Wan, Baonian ; Guo, Houyang ; Zhang, Wei ; Chang, Jiafeng ; Yan, Ning ; Ding, Siye ; Zhang, Ling ; Wang, Liang ; Liu, Shaocheng ; Liu, Peng ; Jiang, Min ; Wang, Huiqian ; Juul Rasmussen, Jens ; Nielsen, Anders Henry ; Xiao, Chijin ; Gao, Xiang ; Hu, Liqun ; Zhu, Sizheng ; Wu, Zhenwei ; Qian, Jinping ; Gong, Xianzu. / A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST. In: Plasma Science and Technology. 2011 ; Vol. 13, No. 4. pp. 397-404.
    @article{2890aaadf21641f48d3dcf8094826ba9,
    title = "A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST",
    abstract = "Ion's toroidal velocity, vt, in both the outermost 4 cm of the confined region and the scrap-off layer of Ohmic L-mode plasmas in EAST was measured using Mach probes. At about 1 cm inside the separatrix a local minimum in vt was observed, from which a cocurrent rotation increased both inwards and outwards. The radial width of the vt dip was 1 cm to 2 cm, and both the density and electron temperature profiles exhibited steep gradients at this dip position. It was observed in both divertor and limiter configurations. To find out its origin, the toroidal torques induced by neutral friction, neoclassical viscosity, collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress were estimated using the measured parameters. Our results indicate that in this particular parameter regime the neutral friction was the dominant damping force. The calculated cocurrent toroidal torque by the neoclassical viscosity dominates over those from the collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress. These results are potentially important for the understanding of boundary conditions for the intrinsic toroidal momentum in tokamak plasmas.",
    keywords = "Fusion energy, Fusioneenergiforskning",
    author = "Guosheng Xu and Volker Naulin and Baonian Wan and Houyang Guo and Wei Zhang and Jiafeng Chang and Ning Yan and Siye Ding and Ling Zhang and Liang Wang and Shaocheng Liu and Peng Liu and Min Jiang and Huiqian Wang and {Juul Rasmussen}, Jens and Nielsen, {Anders Henry} and Chijin Xiao and Xiang Gao and Liqun Hu and Sizheng Zhu and Zhenwei Wu and Jinping Qian and Xianzu Gong",
    year = "2011",
    doi = "10.1088/1009-0630/13/4/03",
    language = "English",
    volume = "13",
    pages = "397--404",
    journal = "Plasma Science and Technology",
    issn = "1009-0630",
    publisher = "IOP Publishing",
    number = "4",

    }

    Xu, G, Naulin, V, Wan, B, Guo, H, Zhang, W, Chang, J, Yan, N, Ding, S, Zhang, L, Wang, L, Liu, S, Liu, P, Jiang, M, Wang, H, Juul Rasmussen, J, Nielsen, AH, Xiao, C, Gao, X, Hu, L, Zhu, S, Wu, Z, Qian, J & Gong, X 2011, 'A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST', Plasma Science and Technology, vol. 13, no. 4, pp. 397-404. https://doi.org/10.1088/1009-0630/13/4/03

    A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST. / Xu, Guosheng; Naulin, Volker; Wan, Baonian; Guo, Houyang; Zhang, Wei; Chang, Jiafeng; Yan, Ning; Ding, Siye; Zhang, Ling; Wang, Liang; Liu, Shaocheng; Liu, Peng; Jiang, Min; Wang, Huiqian; Juul Rasmussen, Jens; Nielsen, Anders Henry; Xiao, Chijin; Gao, Xiang; Hu, Liqun; Zhu, Sizheng; Wu, Zhenwei; Qian, Jinping; Gong, Xianzu.

    In: Plasma Science and Technology, Vol. 13, No. 4, 2011, p. 397-404.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST

    AU - Xu, Guosheng

    AU - Naulin, Volker

    AU - Wan, Baonian

    AU - Guo, Houyang

    AU - Zhang, Wei

    AU - Chang, Jiafeng

    AU - Yan, Ning

    AU - Ding, Siye

    AU - Zhang, Ling

    AU - Wang, Liang

    AU - Liu, Shaocheng

    AU - Liu, Peng

    AU - Jiang, Min

    AU - Wang, Huiqian

    AU - Juul Rasmussen, Jens

    AU - Nielsen, Anders Henry

    AU - Xiao, Chijin

    AU - Gao, Xiang

    AU - Hu, Liqun

    AU - Zhu, Sizheng

    AU - Wu, Zhenwei

    AU - Qian, Jinping

    AU - Gong, Xianzu

    PY - 2011

    Y1 - 2011

    N2 - Ion's toroidal velocity, vt, in both the outermost 4 cm of the confined region and the scrap-off layer of Ohmic L-mode plasmas in EAST was measured using Mach probes. At about 1 cm inside the separatrix a local minimum in vt was observed, from which a cocurrent rotation increased both inwards and outwards. The radial width of the vt dip was 1 cm to 2 cm, and both the density and electron temperature profiles exhibited steep gradients at this dip position. It was observed in both divertor and limiter configurations. To find out its origin, the toroidal torques induced by neutral friction, neoclassical viscosity, collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress were estimated using the measured parameters. Our results indicate that in this particular parameter regime the neutral friction was the dominant damping force. The calculated cocurrent toroidal torque by the neoclassical viscosity dominates over those from the collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress. These results are potentially important for the understanding of boundary conditions for the intrinsic toroidal momentum in tokamak plasmas.

    AB - Ion's toroidal velocity, vt, in both the outermost 4 cm of the confined region and the scrap-off layer of Ohmic L-mode plasmas in EAST was measured using Mach probes. At about 1 cm inside the separatrix a local minimum in vt was observed, from which a cocurrent rotation increased both inwards and outwards. The radial width of the vt dip was 1 cm to 2 cm, and both the density and electron temperature profiles exhibited steep gradients at this dip position. It was observed in both divertor and limiter configurations. To find out its origin, the toroidal torques induced by neutral friction, neoclassical viscosity, collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress were estimated using the measured parameters. Our results indicate that in this particular parameter regime the neutral friction was the dominant damping force. The calculated cocurrent toroidal torque by the neoclassical viscosity dominates over those from the collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress. These results are potentially important for the understanding of boundary conditions for the intrinsic toroidal momentum in tokamak plasmas.

    KW - Fusion energy

    KW - Fusioneenergiforskning

    U2 - 10.1088/1009-0630/13/4/03

    DO - 10.1088/1009-0630/13/4/03

    M3 - Journal article

    VL - 13

    SP - 397

    EP - 404

    JO - Plasma Science and Technology

    JF - Plasma Science and Technology

    SN - 1009-0630

    IS - 4

    ER -