What is the topic of your Ph.D. thesis?
My topic is called „Kinetic approach to computation of plasma equilibria in 3D magnetic fields with general topology“
What is the focus of research?
The goal of my dissertation is to develop a computer code that allows the computation of plasma equilibria in 3D magnetic fields with general topology.
Such a computation is needed, e.g., for the evaluation of plasma response currents and charges caused by external non-axisymmetric electromagnetic perturbations in tokamaks as well as for modeling of edge transport in devices with 3D field geometry.
What is the benefit for fusion research?
From a theoretical point of view there is still a variety of unanswered questions in Plasma Physics. Even though Magnetohydrodynamics is a very powerful theory, essentially kinetic problems cannot be treated correctly, e.g. in a Tokamak we don’t know in detail how Edge Localized Modes (ELMs) are mitigated or even suppressed by Resonant Magnetic Perturbations (RMPs). Therefore, the development of computer models based on first principles are necessary to provide us with a deeper physical insight into the behavior of a plasma under such conditions.
What are the biggest challenges?
One of the key challenges in a kinetic approach to the computation of plasma equilibria is the tracing of millions of particle orbits in a fusion device.
These orbits are usually computed by using adaptive high order ODE integrators, where two big disadvantages arise: First, the particle’s coordinates and velocities are naturally calculated at accuracy-adapted integration steps. In order to calculate the distribution function, these quantities are needed at the boundaries of defined cells, which involves further computational effort. Second, high order spline-interpolation of the field quantities can lead to unwanted oscillations in case of an inaccurate representation of the electromagnetic field, which can destroy the physical properties of the particle orbit.
With my colleagues at TU Graz we have developed a method to compute guiding-center orbits, where computational effort and noise sensitivity are reduced while retaining the conservation of total energy, magnetic moment and phase space volume.
Which plans do you have for your future? What will you do in 5 years? Would you like to continue research or are you going to work in industry?
First things first: For the next 2,5 years I will focus on my research at TU Graz. After that, I can imagine both to pursue an academic career or going to work in the industry.
In my opinion, Plasma Physics especially Controlled Nuclear Fusion will be extremely exciting in 5 years, since the first ITER plasma is scheduled for December 2025. This important milestone will mark a historical event in the development of fusion devices.
What was your motivation to write a fusion relevant Ph.D. thesis? What is fascinating about nuclear fusion?
In the Middle Ages generation after generation was involved in the construction of magnificent cathedrals all over Europe. Nowadays, Nuclear Fusion is a similar ambitious undertaking across generations: Research into fusion reactors began already in the 1940s, but still, we cannot expect to have fusion energy in the grid before the second half of this century, realistically.
If this is not a challenge?