Visualization of magnetically confined plasmas

Lewandowski, J. L. V.

doi:10.1007/s007910050017

Cited by 2 publications

(1 citation statement)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Negative normal curvature is destabilizing to ballooning instabilities, and all else being equal, the turbulent growth rate and fluxes for unstable modes have been found to scale roughly linearly with negative normal curvature [19]. Local magnetic shear s l linearly stabilizes turbulent modes by bending radially adjacent field lines, and is given by [20,21],…”

Section: Calculations Of 3d Curvature and Local Magnetic Shear From Vmecmentioning

confidence: 98%

Modeling of 3D magnetic equilibrium effects on edge turbulence stability during RMP ELM suppression in tokamaks

et al. 2017

View full text Add to dashboard Cite

Recent experimental observations have found turbulent fluctuation structures that are non-axisymmetric in a tokamak with applied 3D fields. In this paper, two fluid resistive effects are shown to produce changes relevant to turbulent transport in the modeled 3D magnetohydrodynamic (MHD) equilibrium of tokamak pedestals with these 3D fields applied. Ideal MHD models are insufficient to reproduce the relevant effects. By calculating the ideal 3D equilibrium using the VMEC code, the geometric shaping parameters that determine linear turbulence stability, including the normal curvature and local magnetic shear, are shown to be only weakly modified by applied 3D fields in the DIII-D tokamak. These ideal MHD effects are therefore not sufficient to explain the observed changes to fluctuations and transport. Using the M3D-C1 code to model the 3D equilibrium, density is shown to be redistributed on flux surfaces in the pedestal when resistive two fluid effects are included, while islands are screened by rotation in this region. The redistribution of density results in density and pressure gradient scale lengths that vary within pedestal flux surfaces between different helically localized flux tubes. This would produce different drive terms for trapped electron mode and kinetic ballooning mode turbulence, the latter of which is expected to be the limiting factor for pedestal pressure gradients in DIII-D.

show abstract

Section: Calculations Of 3d Curvature and Local Magnetic Shear From Vmecmentioning

confidence: 98%