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Title: Quasilinear theory of interchange modes in a closed field line configuration

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.2773711· OSTI ID:21057443
; ;  [1]
  1. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

Two important issues for any magnetic fusion configuration are the maximum achievable values of {beta} and energy confinement time when ideal magnetohydrodynamic (MHD) modes are excited. It is well known that the excitation of the MHD unstable modes typically can lead to violent restructuring of the plasma profiles. The particle and energy transport associated with these modes normally dominates all other transport mechanisms and can lead to plasma disruptions and a rapid loss of energy. This paper analytically investigates the transport of particle density, energy, and magnetic field due to the ideal MHD interchange mode in a closed-line system using the quasilinear approximation. The transport equations are derived for a static plasma in a hardcore Z-pinch configuration and generalized to an arbitrary axisymmetric toroidal closed poloidal field line configuration. It is shown that violation of the marginal stability criterion leads to rapid quasilinear transport that drives the pressure profile back to its marginal profile and forces the particle density to be inversely proportional to {integral}dl/B. The applicability of the quasilinear approximation is numerically tested for the hardcore Z-pinch magnetic configuration using a full nonlinear code.

OSTI ID:
21057443
Journal Information:
Physics of Plasmas, Vol. 14, Issue 10; Other Information: DOI: 10.1063/1.2773711; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English