Being responsible for the DEMO conceptual design, the EFDA Power Plant Physics and Technology Department comprises mostly engineers. Recently, EFDA appointed fusion scientist Ronald Wenninger to ensure that the design work reflects the current physical knowledge.

Ronald, how does it feel to work as a plasma physicist within a group of engineers?

It is really fascinating! I enjoy working at this interface between physics and engineering.

What are you doing in your job?

Our department prepares the step from ITER to DEMO. It is important to work on this now in order to enable a fast track to fusion energy. I am responsible for DEMO physics integration. My job is to make sure that as much of the available physical knowledge as possible enters our design considerations.
The core of our investigations is a system code, which models the full DEMO plant with a relatively low level of detail. We use this code to find an optimum set of key parameters of DEMO such as dimensions, magnetic field, plasma current etc. In order to keep this consistent with the current knowledge we employ state-of-the-art physics codes to investigate partial aspects, for example plasma stability, with a much higher level of detail.

After your physics studies, you worked as a physics teacher. Why did you later enter fusion science?

After a few years in school, I needed new ideas and new challenges. I was able to start working for EFDA at JET in the area of machine operation. Later I was involved in various fields, for instance in the ITER-Like-Wall project and in the high frequency pellet injector project, for which I became deputy project leader. Plasma physics, though, was quite new to me. I began reading the scientific literature and really enjoyed studying again. In my spare time I started to do my own research. When I returned to Germany, I got the opportunity to do a PhD at IPP with Hartmut Zohm as supervisor. I consider myself really lucky, because I could learn endlessly from him.

You successfully finished your PhD some months ago – what is it about?

Generally speaking, it is about the physics of edge localized modes (ELMs). This is a hot topic in fusion science, as ELMs cannot be tolerated in future fusion devices. There are non-linear processes during the evolution of an ELM and in order to predict an ELM correctly, one needs to understand these better. I compared ELM simulations with data from experiments in ASDEX Upgrade at IPP and in TCV at CRPP. My work led to a more complete picture of the processes during ELMs. Eventually it might also contribute to an ELM model, which is capable of reliably predicting ELM sizes and evolution.

Will you still find time for your band, then?

Oh, yes! Together with Harmut Zohm, Thomas Eich and some others I am playing in a band called “Arbitrary Unit”. We do vintage rock and modern tunes – just cover songs. I sing and play guitar.