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Symplectic Computations of Fast Ion Trajectory and Radial Diffusion Coefficient in MHD Perturbed Tokamak

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Abstract

The magneto-hydrodynamics (MHD) modes existing in conducting plasmas can greatly affect charged particle’s dynamics. Low frequency MHD perturbations, called the neo-classical tearing (NTM) modes, give rise to magnetic islands which can deteriorate fast ion confinement, especially in tokamak plasmas. Here, a Hamiltonian guiding-center code, based on symplectic algorithm which allows efficient computations of energetic ion trajectories and transport coefficients, has been applied to magnetically perturbed tokamak plasmas. The effects of NTM perturbations on the energetic ion trajectories and diffusion coefficient have been presented. It is demonstrated that the inclusion of such steady state magnetic perturbations in the guiding center drift orbit computations escalates the loss of energetic ions via radial diffusion. Moreover, the broader NTMs lead to a significant enhancement of the radial diffusion coefficient.

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Authors and Affiliations

  1. Department of Physics, COMSATS University Islamabad, Park Road, Chak Shahzad, Islamabad, Pakistan

    M. Kamran

  2. Department of Physics, Quaid-i-Azam University, Islamabad, 45320, Pakistan

    Majid Khan & M. H. Khalid

  3. Department of Physics, Abdul Wali Khan University, Mardan, Pakistan

    R. Khan

Authors
  1. Majid Khan
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  2. M. H. Khalid
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  3. M. Kamran
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  4. R. Khan
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Correspondence to M. Kamran.

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Khan, M., Khalid, M.H., Kamran, M. et al. Symplectic Computations of Fast Ion Trajectory and Radial Diffusion Coefficient in MHD Perturbed Tokamak. J Fusion Energ 39, 77–85 (2020). https://doi.org/10.1007/s10894-020-00236-7

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