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Lecture

MHD Equilibrium: Equations and Applications

Description

This lecture covers the equations for static ideal MHD equilibrium, including continuity, momentum, Ohm's law, and closure equations. It also discusses force-free and force-balanced equilibria, such as the Z-pinch and 9-pinch, with applications to plasma physics.

In MOOC

Plasma Physics: Introduction

Official source

Quiz

Ontological neighbourhood

Physics

Plasma physics: Fusion power

Related concepts (32)

Pinch (plasma physics)

A pinch (or: Bennett pinch (after Willard Harrison Bennett), electromagnetic pinch, magnetic pinch, pinch effect, or plasma pinch.) is the compression of an electrically conducting filament by magnetic forces, or a device that does such. The conductor is usually a plasma, but could also be a solid or liquid metal. Pinches were the first type of device used for experiments in controlled nuclear fusion power. Pinches occur naturally in electrical discharges such as lightning bolts, planetary auroras, current sheets, and solar flares.

Plasma (physics)

Plasma () is one of four fundamental states of matter, characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun. Extending to the rarefied intracluster medium and possibly to intergalactic regions, plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field.

Plasma stability

The stability of a plasma is an important consideration in the study of plasma physics. When a system containing a plasma is at equilibrium, it is possible for certain parts of the plasma to be disturbed by small perturbative forces acting on it. The stability of the system determines if the perturbations will grow, oscillate, or be damped out. In many cases, a plasma can be treated as a fluid and its stability analyzed with magnetohydrodynamics (MHD).

Z-pinch

In fusion power research, the Z-pinch (zeta pinch) is a type of plasma confinement system that uses an electric current in the plasma to generate a magnetic field that compresses it (see pinch). These systems were originally referred to simply as pinch or Bennett pinch (after Willard Harrison Bennett), but the introduction of the θ-pinch (theta pinch) concept led to the need for clearer, more precise terminology. The name refers to the direction of the current in the devices, the Z-axis on a normal three-dimensional graph.

Theta pinch

Theta-pinch, or θ-pinch, is a type of fusion power reactor design. The name refers to the configuration of currents used to confine the plasma fuel in the reactor, arranged to run around a cylinder in the direction normally denoted as theta in polar coordinate diagrams. The name was chosen to differentiate it from machines based on the pinch effect that arranged their currents running down the centre of the cylinder; these became known as z-pinch machines, referring to the Z-axis in cartesian coordinates.

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