Sorry, you need to enable JavaScript to visit this website.

You are here

Matthias Werl - MSc thesis at CNT

After having worked at both the IPP in Greifswald and Garching, I wanted to go somewhere outside of Europe to continue my research in Nuclear fusion. From this, the opportunity arose to perform research for my MSc thesis at the Columbia University in the City of New York.


The Columbia (non-)neutral torus is a small research device operated by the plasma physics laboratory of Columbia University. Initially used to study (non-)neutral electron plasmas, it has since been modified to study neutral plasmas. Consisting of only 4 coils, it is one of the simplest stellarators worldwide. Recent experiments focused on over-dense microwave heating to study high beta plasmas; which works well in CNT due to its small machine size. The machine was constructed by Thomas Sunn Pedersen, my supervisor during my time in Greifswald, but has since been taken over by Francesco Volpe. It was only because of him and the support from FuseNet that enabled this amazing experience.

My internship started soon after I left another research internship at the IPP in Garching, and after being home for only a few days, I took off from Vienna to start my journey. Since this was my first trip to the US (and outside Europe, for that matter), I was utterly amazed upon first arriving in New York City. After making myself at home in my new shared apartment, I visited the Columbia campus already a few days in advance to meet my professor and my future lab mates.

The topic of my work was to explain a synergistic effect observed when microwave heating was used in addition to a heated and biased filament, previously used to start the plasma. When using both mechanisms simultaneously, the observed densities were higher than the sum of the densities of each method used alone. A few candidate mechanisms were proposed to explain this synergy, but my main focus was on the fact, that faster electrons can absorb the microwaves more efficiently. To quantify this effect, a particle tracing code was adapted to trace electrons in the magnetic field and the microwave field. Therefore, several new events such as collisions as well as ultimately the wave absorption needed to be implemented.

Science, free-time and roadtrips

During my stay, another MSc student from Europe was at the lab as well. He was working on a prototype for a new type of fusion device. I spent lots of time with him and the group working on the same projects and this really enhanced my experience. Besides going to the city center, driving to the beach, taking bike rides and going to explore the city as often as possible, we also went on a couple of trips to explore the country and make the most out of our stay. At one point, I even got a visit from former colleagues from the IPP while they were on their way to a conference at the PPPL.

The first trip we took was going further Northeast and see Boston. As home of the Alcator C-Mod, the MIT was naturally of high interest for all of us working in the field. With a bit of luck, we found a PhD student who was willing to show us this machine (which unfortunately is not in use anymore) and talk about working at the MIT and SPARC, the new project soon to be started.

For the second trip, we went further South to visit Philadelphia, Baltimore and the US capital, Washington D.C. On our way, we stopped at the PPPL, probably the biggest fusion research facility in the US. Once again, we were lucky to have a PhD student show us around and tell us about life and research in Princeton.

Many months, countless incredible experiences and valuable life lessons as well as invaluable research experience later, I am now back in Austria at the verge of finishing my last classes and my thesis and I’m looking forward to continuing my journey!

At this point I want to once again thank Mr. Pedersen for establishing contact and Francesco Volpe for enabling and supervising me as well as FuseNet for their help, guidance, and support!

- Matthias Werl