STSM Success Stories — Johannes Reichegger
This article is a part of a series where we highlight some of the research collaborations made possible by Short Term Scientific Missions funded by the COSY COST Action.
Johannes Reichegger is a PhD student at the Institute for Ion Physics and Applied Physics and the University of Innsbruck. He works in an experiment group led by Professor Paul Scheier and studies fundamental processes involving helium nanodroplets but has developed an interest in theoretical modeling. With an STSM grant from COSY he spent two weeks working with Professor Nadine Halberstadt at the University of Toulouse.
What is the background of this project?
I attended the Quantum Fluid Conference in Aarhus last year where Nadine Halberstadt presented her work on simulating collisions between helium droplets. What she saw was that they readily form quantum vortices which are a are quite hot topic within our community. They have been observed by many different groups, theoretically and experimentally, but the origin is not so well understood. With my supervisor’s support we had the idea to collaborate with Nadine for our own project studying helium droplets colliding with surfaces.
What did you do during the STSM?
I learned how to use the code that Nadine Halberstadt’s group have been using to study colliding helium droplets and how to apply it for droplets colliding with surfaces at small incident angles. Because of interactions with the surface, the droplets gain angular momentum which, due to the helium being a quantum fluid, must be quantized within the droplet. I started with the basics of handling the code, like building a simulation box and setting the correct parameters. Already in my first preliminary results I saw that there is a lot of angular momentum transferred to the droplets, enough to even boil off most of the helium in small droplets. We will continue this collaboration by studying how larger droplets behave.
How has the support from COSY helped you in this research?
I’m really grateful that COSY gave me this opportunity because otherwise I don’t think that there would have been a possibility for me at this stage in my career to do this kind of exchange. This collaboration will probably continue for the next few years at least and I expect there will be a lot of papers coming out of it. The project helped sparked more of my interest into theory because I come from an experimental group, so this was kind of a match made in heaven for my supervisor Paul Scheier that I could do this as well.
