Disciplines
Physics, Astronomy (100%)
Keywords
Plasma physics,
Fusion energy,
Plasma turbulence,
Computational Physics
Abstract
Turbulence is a common phenomenon in flows of fluids and gases. Accurate and
meaningful models and computer simulations of turbulent processes are required, both for
the understanding of natural flows such as in weather dynamics, and for development and
optimisation of numerous technical applications.
In gases at very high temperatures, the electrons can detach from the atoms, and such an
ionised gas is called a plasma. Plasma is the matter, of which the sun and all the stars are
made, and for many technical applications plasmas are confined by magnetic fields. A
promising potential future technological application is the development of fusion energy by
employing hundreds of million degrees hot, magnetised plasmas.
Large temperature differences in fusion plasmas can cause fierce and unfavourable
turbulent flows and transport losses. An improved understanding of turbulence and its
physics basis in plasmas by experiments and according theoretical models is thus also an
important task in fusion research.
Previous models and computer simulations of turbulence in hot magnetised plasmas have
mostly used efficient approximations and simplifications, such as a limitation to small
amplitudes or to certain length scales of the turbulent vortices. However, especially at the
edge of fusion plasmas turbulent structures with large amplitudes are encountered.
Further, some essential physical interaction mechanisms between turbulent vortices exist
also on such scales, which were previously neglected in models for large amplitudes.
Recently a novel nonlinear turbulence model for magnetised plasmas has been
developed, which is applicable both for large amplitudes and for all relevant scales.
In this project these new generalised models for turbulence in magnetised plasmas,
accounting simultaneously for arbitrary amplitudes ("full-f") and arbitrary relevant scales
("full-k"), are going to be extended and for the first time applied on topical problems in
fusion research by numerical simulations.
The developments and expected results of this project are not only applicable on an
improved understanding of turbulence in fusion plasmas, but also on other fundamental
nonlinear phenomena in magnetised plasmas, which can be encountered in astro physics
or in the laboratory for example in the form of electron-positron plasmas.