From April – June 2022 I performed my Master’s internship project at the Plasma Modelling and Analysis Section at ITER. I was supervised by Guido Huijsmans and Sven Korving who helped me to implement hydrogenic molecules and the associated reaction in the nonlinear MHD code JOREK. Hydrogenic molecules are important where the temperature is low (divertor region) and are an energy and momentum sink of the plasma. These molecules can be puffed into the plasma or are formed by recombination at the wall.
At the start, I had little experience in programming, and it was the first time I used FORTRAN and Linux. However, with the supervision I got, it was possible to learn a lot in a short time. I started with exploring the theory behind molecular reactions and looked for a suitable database covering all reaction rates and associated energy losses. After this, I thought about how to implement these reactions in the code in the first place and later, as efficiently as possible. Even more, I learned how to write a piece of code that cooperates with the rest of the big MHD code and gives feasible results. For this, a lot of checks were needed that seemed a bit tiresome but proved to be essential and insightful. In the end, I managed to implement molecules and the associated reactions with the plasma, and, as a first application, I ran a test case of an ITER H-mode. Additionally, I learned a lot about parallelizing, bug-fixing, supercomputers, other MHD codes and the daily life at the forefront of fusion research and engineering.
Next to these project-related topics, the internship offered a lot more.
Being welcomed and introduced by Emma and Tim (see previous posts) to the other ITER interns was very nice. They left after a short time but soon a lot of new interns came and we formed a close group. Every day, the lunch was great, and (almost always) the morale was high in the interns’ office. It was incredible to meet such a diverse and multicultural group of people. On the weekends, we went on trips all over the Provence. I enjoyed the interactions with the Ph.D. students and postdocs working on site, a site tour including a visit in the tokamak pit with a recently placed vacuum vessel sector.
Being a fervent cyclist, I was happy to hear that there was an ITER cycling club with fellow passionate cyclists. With these people, I made great bike tours on the weekends and evenings, for example climbing Mt. Ventoux, commuting together to ITER from Aix or mountainbike tour near St. Victoire with my supervisor Sven. The Provence really lends itself to outdoor activities (when the weather is not too hot). All in all, it was an experience to remember!