[English]

Prosiectau Ffiseg ar gyfer myfyrwyr bl.3 a bl.4


Disgrifiad prosiect

Non-linear Alfven waves

(supervisor: Xing Li)

Nature of project: theory, data analysis

Available to students on full-time physics degree schemes only.

Project description and methodology

In space and astrophysical systems, materials are often fully ionized (known as plasma) and magnetic field often plays a role in the systems. Such systems can support various wave activities. Among the waves, Alfven waves are the most common wave form expected and indeed often observed. Linear Alfven waves, together with other plasma waves, can be easily excited. Solutions of non-linear Alfven waves also exist. It is widely believed that these waves eventually may develop instabilities and turbulence. The goal of this project is to critically review the theoretical development of non-linear Alfven waves under certain conditions (uniform background, or the wavelength of Alfven wave is much smaller than the size of a system) and re-develop the theory of these waves.

A successful project will develop beyond the above in one/some of the following directions:
To find evidence of non-linear Alfven waves using space plasma data.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: As a 4th year project, it is expected that the stability of non-linear Alfven waves will be investigated.

Please speak to Xing Li if you consider doing this project.

Initial literature for students:

  1. Introduction to plasma physics, by DA Gurnett and A Bhattacharjee, Cambridge University Press, 2005.
  2. A. Barnes, J.V. Hollweg, Large-amplitude hydromagnetic waves, Journal of Geophysical Research, DOI: 10.1029/JA079i016p02302, 1974.
  3. P. Riley et al., Properties of arc-polarized Alfvén waves in the ecliptic plane: Ulysses observations, Journal of Geophysical Research, DOI: 10.1029/96JA0174, 1996

Novelty, degree of difficulty and amount of assistance required

New project.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Initial rough idea of Alfven wavesend of October
Know the basics of Alfven wavesChristmas
Able to develop solutions of non-linear Alfven waves end of February
Non-linear Alfven waves with non-uniform background,mid-March