A journey into plasma cleaning for fusion optical components– my Master’s internship at the University of Basel
My name is Nicolo Lopopolo, and I am a Master’s student in Nuclear Engineering. Thanks to the support `
of FuseNet, I had the chance to spend six incredible months at the University of Basel, in Switzerland, to
carry out my Master’s thesis. I joined the NanoLino Group at the Department of Physics – an inspiring
environment where I was warmly welcomed and guided through a unique research experience at the
crossroads of nanotechnology and nuclear fusion.
My project, titled ”Investigation of tungsten and boron thin films for fusion applications”, focused on
one of the critical challenges in fusion diagnostics: the cleaning of first mirrors from plasma-induced
contamination. Specifically, I studied how plasma cleaning techniques can remove boron-based deposits
(pure or mixed with tungsten, deuterium or oxygen) from platinum-coated mirrors, which are used to
reflect light into optical diagnostics systems in fusion reactors. I explored the efficiency of different
working gases, and carefully analyzed the reflectivity of mirrors before and after the cleaning process.
These optical properties are vital to ensure accurate diagnostics in ITER and other fusion devices, where
in-situ cleaning solutions are being actively developed.
During my internship, I had the opportunity to learn and work hands-on with advanced techniques and
equipment: cold plasma systems for surface treatments and thin film deposition with magnetron sputtering,
ultra-high vacuum systems, scanning electron microscopy (SEM), Focused Ion Beam (FIB) and
UV-VIS spectrophotometry. It was a deep dive into experimental physics and surface science, and it
greatly expanded both my technical skills and my scientific perspective.
What made the experience truly special was the supportive and collaborative atmosphere within the
NanoLino Group. My supervisor and colleagues were always available, enthusiastic, and willing to
share their knowledge. Thanks to them, I felt part of a real scientific team and grew both as a researcher
and as a person.
Living in Basel was another highlight of the internship. The city is a cultural capital of Switzerland, with
world-class museums, vibrant student life, and a perfect location for travel. On weekends, I explored
not only the Swiss Alps and lakes, but also nearby France and Germany – visiting cities like Colmar,
Strasbourg and Freiburg im Breisgau. Basel gave me a perfect balance between research intensity and
cultural richness.
This internship has confirmed my passion for fusion research. Contributing, even in a small way, to the
development of solutions that might one day bring the energy of the Sun to Earth was both humbling
and exciting. I am very grateful to FuseNet for supporting this experience, and I strongly encourage
any student with an interest in fusion to seize this kind of opportunity. It might change the way you see
science – and your future.
