as a future energy source
confinement fusion is a promising candidate for a clean, reliable and
sustainable energy source. The idea is to fuse hydrogen isotopes to Helium, a
process that releases a large amount of energy. This process has kept our Sun
burning for the last four billion years. However, the necessary temperatures to
sustain fusion on Earth lie around 100 Million Kelvin. A gas this hot is in the
so-called plasma state and is typically highly turbulent. On the Sun, this
manifests in the form of solar flares that expel into the surrounding empty space.
On Earth, we have to confine the plasma with magnetic fields and material
walls. A corresponding flare can therefore hit a plasma facing material
component of the wall, which is then subject to similar or even higher heat
loads to a spacecraft reentering Earth’s atmosphere. A heat load this high is
unacceptable in a fusion power plant. Since the lifetime expectancy of such a
plant should be years, it is crucial to understand and ultimately inhibit
certain unwanted transport processes in the plasma.
institute recently acquired a so-called tokamak. A tokamak is essentially a
toroidally shaped vacuum vessel together with a magnetic field that confines
the plasma. It can be viewed as the small scale version of the future fusion
power plant and is well-suited for the study of plasma behavior.
description of low-frequency phenomena in magnetized plasmas, so-called drift-reduced
Braginskii (also called drift-fluid) and gyro-fluid models are efficient. Both
of these approaches remove the fast time and spatial scales associated with the
gyration of charged particles in the magnetic field. Compared to the most
accurate kinetic descriptions the reduced dimensionality in fluid models significantly
lowers the complexity of the model. Still, purely analytical approaches exist
only for the most simplified model equations.
the complexity of the underlying model equations, we use simulations to gain insight
into the physical mechanisms of the plasma. The value of simulations is that
they offer a complete determination of all variables involved. Ideally, a
simulation is a virtual laboratory.
of this project is to study the plasma in the new tokamak with the help of
numerical simulations. Open research questions are for example the fluctuation
levels of the plasma density or the optimization of magnetic field configuration.
The work will be in close collaboration with the experimental group in our
institute. Ideally, the simulation results will be validated against
experimental probe measurements. The simulations will be setup with the help of
the Feltor library (https://feltor-dev.github.io). Feltor is an easy-to-use free software
package that we have developed particularly for the use in drift- and
We offer both bachelor and master theses on this topic.
Fluid- and Electrodynamics are advantageous