Physicist Isabel Krebs joins DIFFER to study and optimize computational models for hybrid operation scenarios in tokamak fusion reactors. These offer a possibility for longer, more stable discharges in future fusion power plants. Isabel Krebs' Postdoc postion at DIFFER is funded by one of the prestigious Researcher Grants of EUROfusion, the European consortium for fusion energy research.
Tokamaks are the leading design for future fusion power plants that would generate clean, safe and abundant power by fusing hydrogen isotopes into helium. Isabel Krebs wants to investigate the hybrid mode of tokamak operation. In hybrid mode the plasma discharges are maintained longer by driving a stabilizing current via other systems than the regular pulsed transformer. The challenge is to understand and predict how the plasma behaves in this advanced mode, which offers great potential for future power plants.
How will you tackle this topic of hybrid discharges?
"We especially want to study the role that magnetic flux pumping plays in hybrid discharges. Magnetic flux pumping is a self-regulating mechanism that automatically maintains some of the conditions for the desirable properties of hybrid discharges without the need for external control. To do this, we will set up 3D nonlinear MHD simulations and validate our theoretical model against experimental measurements. From that validated but computationally expensive simulation we then want to generate a simplified, reduced (and faster) model of magnetic flux pumping that helps researchers to plan experiments and improve tokamak operation."
How did you join fusion research?
"Since my undergrad days I have always had a fascination for hydrodynamics. I became interested in fusion research when I learned you can combine hydrodynamics with magnetic and electric fields, to get MHD or magnetohydrodynamics, a theoretical tool for the quest for a novel, clean energy source. This way you can model the various large scale instabilities you can have in tokamaks.
"I've been working on nonlinear MHD simulations since my PhD in physics at the Technical University Munich. This included research at the German Max Planck Institute for Plasma Physics, and the USA's Princeton Plasma Physics Lab where I completed a Postdoc."
What brought you to DIFFER?
"The tools I want to develop require expertise in different fields, namely nonlinear magnetohydrodynamics and integrated modeling. At DIFFER there are experts in both these fields to collaborate with, and the institute has good connections to the international world of fusion. I like being part of a large international community of researchers with a common goal that will benefit society."