中国物理B ›› 2014, Vol. 23 ›› Issue (10): 105201-105201.doi: 10.1088/1674-1056/23/10/105201

• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇    下一篇

Numerical study of fast ion behavior in the presence of magnetic islands and toroidal field ripple in the EAST tokamak

张伟, 胡立群, 孙有文, 丁斯晔, 张子君, 刘松林   

  1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
  • 收稿日期:2014-03-05 修回日期:2014-04-16 出版日期:2014-10-15 发布日期:2014-10-15
  • 基金资助:
    Project supported by the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics (NSFC Grant No. 11261140328).

Numerical study of fast ion behavior in the presence of magnetic islands and toroidal field ripple in the EAST tokamak

Zhang Wei (张伟), Hu Li-Qun (胡立群), Sun You-Wen (孙有文), Ding Si-Ye (丁斯晔), Zhang Zi-Jun (张子君), Liu Song-Lin (刘松林)   

  1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
  • Received:2014-03-05 Revised:2014-04-16 Online:2014-10-15 Published:2014-10-15
  • Contact: Hu Li-Qun E-mail:lqhu@ipp.ac.cn
  • About author:52.20.Dq; 52.65.-y; 52.25.Fi
  • Supported by:
    Project supported by the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics (NSFC Grant No. 11261140328).

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摘要： A peculiar first orbit loss type was found apart from the normal ones when we use ORBIT code to simulate fast ion orbits in the EAST tokamak. Fast ion orbits were studied in the presence of toroidal field (TF) ripple and magnetohydrodynamic (MHD) perturbations. We analyzed the properties of the drifted orbits in detail and compared their differences, finding that the combined effects of ripple and magnetic islands are much greater than the effects of either one of them alone. Then we investigated the orbit deviations as a function of pitch angle in different radial positions. The modeling results demonstrate that the loss of trapped particles is mainly caused by the ripple, while MHD perturbation mainly plays an important role in the passing particles. Furthermore we modeled the loss rate using different equilibriums. Results prove that a higher beta can indeed improve the confinement of fast ions, while a little change in the q profile can make the topologies of magnetic islands become quite different and results in quite different total particle losses.

关键词: fast ion, toroidal field ripple, magnetic island, orbit drift

Abstract: A peculiar first orbit loss type was found apart from the normal ones when we use ORBIT code to simulate fast ion orbits in the EAST tokamak. Fast ion orbits were studied in the presence of toroidal field (TF) ripple and magnetohydrodynamic (MHD) perturbations. We analyzed the properties of the drifted orbits in detail and compared their differences, finding that the combined effects of ripple and magnetic islands are much greater than the effects of either one of them alone. Then we investigated the orbit deviations as a function of pitch angle in different radial positions. The modeling results demonstrate that the loss of trapped particles is mainly caused by the ripple, while MHD perturbation mainly plays an important role in the passing particles. Furthermore we modeled the loss rate using different equilibriums. Results prove that a higher beta can indeed improve the confinement of fast ions, while a little change in the q profile can make the topologies of magnetic islands become quite different and results in quite different total particle losses.

Key words: fast ion, toroidal field ripple, magnetic island, orbit drift

中图分类号:  (Particle orbits)

  • 52.20.Dq
52.65.-y (Plasma simulation) 52.25.Fi (Transport properties)