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Ballooning instability

2026-04-14T08:57:06Z

Jspeake: Create stub article for Ballooning instability

The <b>ballooning instability</b> is a pressure-driven [[Plasma instability|instability]] characterised by wide poloidal spectra, generally at high toroidal mode numbers, <math>n>10</math>. Ballooning modes typically manifest in the outboard edge region of tokamaks operating in [[H-mode|high confinement regimes]], owing to large edge gradients. This outboard localisation is due to the curvature dependence of the more general interchange instability, where the inboard side of the tokamak typically possesses more favourable [[Magnetic curvature|curvature]]. <ref> D. Brunetti, Basics of MHD in Tokamaks, 2025, UKAEA</ref>
== Relationship with ELMs ==
Ballooning modes, coupled with the [[Peeling instability|peeling instability]], are a proposed mechanism for driving the ELM cycle, as part of the [[Peeling-Ballooning Model|peeling-ballooning model]] of [[Edge_Localized_Modes|Edge Localised Modes]] (ELMs).
== References ==

Ideal Magneto-Hydrodynamics

2026-04-13T13:32:12Z

Jspeake: redirect: Ideal Magnetohydrodynamics -> Ideal MHD

#redirect [[Ideal MHD]]

Ideal MHD

2026-04-13T13:31:16Z

Jspeake: Created stub article for Ideal MHD

Ideal MHD (magnetohydrodynamics) is a simplification of MHD which assumes no plasma resistivity. The definition of the electric field, <math>\mathbf{E}</math>,
:<math> \mathbf{E}+\mathbf{v}\times\mathbf{B}=\eta\mathbf{J} </math>
is simplified (setting resistivity <math>\eta</math> to zero) to
:<math>\mathbf{E}=-\mathbf{v}\times\mathbf{B}</math>
for a fluid velocity <math>\mathbf{v}</math> and magnetic field <math>\mathbf{B}</math>. This allows for simple representations of [[MHD equilibrium|MHD equilibria]].
== Limitations ==
Ideal MHD cannot model physical phenomenon requiring resistivity. This imposes the 'frozen-in flux' condition where magnetic field lines are bound to fluid elements. This prevents modelling of, for example, [[Reconnection|magnetic reconnection]] events.

ELM

2026-04-06T13:40:48Z

Jspeake: redirect: ELM -> Edge Localized Modes

#REDIRECT [[Edge_Localized_Modes]]

User:Jspeake

2026-04-06T13:31:11Z

Jspeake: Created page with "====:)==== PhD student at Uni of York, studying edge stability of magnetic confinement plasmas."

====:)====
PhD student at Uni of York, studying edge stability of magnetic confinement plasmas.