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PX3A4 Plasma Physics and Fusion

Lecturer: Ben McMillan
Weighting: 15 CATS

Plasmas are 'fluids' of charged particles. The motion of these charged particles is controlled by the electromagnetic fields which are imposed from outside and by the fields which the moving charged particles themselves set up. This module will cover the equations which describe such plasmas. It will examine some predictions derived on the basis of these equations and compare these with laboratory observations and with remote observations of astrophysical systems.

The module will also discuss the physics of thermonuclear fusion, which is a candidate solution for the energy demands of our society. Fusion occurs only at temperatures at which all matter is ionized and exists as a plasma. The module discusses the two main approaches: inertial confinement and magnetic confinement, with the emphasis on the latter since it is further developed. The module will deal with both the physics in the plasma as well as with the boundary conditions that must be satisfied for a working reactor.

The module should discuss particle dynamics in plasmas, and aspects of nuclear fusion and advanced plasma physics relevant to the construction of fusion power stations. The interaction of EM fields with a fully ionised fluid (plasma) should be considered in detail leading to ideas of magnetohydrodynamics.


By the end of the module, students should be able to:

  • Work with single particle dynamics, guiding centre motion and adiabatic invariants, the plasma approximation and waves in plasmas
  • Describe the nature of fluid instabilities and micro-instabilities with application to confinement devices and astrophysics
  • Explain the interaction of electromagnetic waves with plasmas
  • Appreciate how plasma physics sets the design parameters of fusion power plants
  • Explain the physics of fusion power plasma heating, confinement and stability


Foundations, Debye shielding, Plasma oscillations, Gyration and drifts; Dielectric description of magnetised plasmas;
Dispersion relations for high-frequency EM waves in a cold plasma;
Elements of plasma kinetics: Landau damping, Bump-on-tail instability; Magnetohydrodynamics: Framework, Equilibria, Waves, Instabilities;

Fusion Foundations, Lawson criterion;
Cylindrical equilibria, including z pinch;
Mirror machines, Tokamaks and stellarators; Laser-plasma interaction and inertial confinement fusion; Transport and turbulence

Commitment: 30 Lectures

Assessment: 2 hour examination.