Fabien Saladini and Konstantin Kaufhold leave the working group
08/31/2025
Fabien did an internship with us. He was tasked with investigating the influence of the Kubo number on drift wave turbulence in VINETA.75. In addition, over the past few months he has developed into a very valuable member of the working group in all areas. He helped us understand the RF suitability of our Langmuir probes. It is really hard for us to let him go.
Konstantin has submitted his bachelor's thesis, in which he studied the fundamental dynamics of vortices in drift wave turbulence. He used BOUT++ to perform simulations for this. He is the first bachelor's student to finish his degree in our working group. We would like to thank Tobias Tork, Theo Gheroghiu, and Roman Ghiam for their support in supervising Konstantin, and Konstantin himself for his great work.
Review article on density and radiation limits in tokamaks published
08/04/2025
Operating a tokamak at high confinement, high heating power, and high density is likely to encounter the H-mode density limit (HDL), making it a central issue for magnetically confined fusion. Despite its importance, the HDL is far from being as thoroughly investigated and understood as its counterpart in the L-mode. There are several mechanisms that limit the achievable density, and theories have been developed that show excellent agreement with the experiments. However, when examining the observations in the various tokamaks, these are contradictory. But if these are viewed as competing mechanisms that limit the achievable density of the H-mode, the observations can be reconciled. The article was recently published in Nuclear Fusion.
Tabletop protoplanetary disk
07/03/2025
We have succeeded in setting up a laboratory experiment with which we can simulate Keplerian rotation, which is relevant for astrophysical accretion disks. It is based on a tornado in which the rotation is introduced by counter-rotating water jet streams. The resulting hyperbolic free surface acts as an effective gravitational potential. Using tracer particles, the Keplerian rotation profile could be demonstrated.
This work was recently published by Stefan Knauer in Monthly Notices of the Royal Astronomical Society.
07/21/2025