Engineering Design of the Test Section for Tritium Extraction from PbLi using a Vacuum Sieve Tray
Report by Merlijn Mertens. Powered by FuseNet

My name is Merlijn Mertens. I’m a Belgian student involved in nuclear fusion since almost two years ago when I started my European Master in Nuclear Fusion and Engineering Physics. This Master requires flexibility and mobility and thus I had to make some personal sacrifices to enter but those were abundantly compensated by the high-level education, the amazing experiences and the chances to work in specialized research centers. I spent last year in Madrid studying at the Universidad Complutense de Madrid and Universidad Carlos III de Madrid. There I joined the rugby team of the physics faculty and made a lot of new friends this way. It was an amazing time! The first semester of this year I studied at the University of Ghent which is the main institution organizing this Master. Thanks to the connections of the steering committee, I was offered the chance to carry out my Master’s thesis work at the Karlsruhe Institute of Technology (KIT), more specifically in the Tritium Laboratory of Karlsruhe (TLK). I chose this institution because my main interests within the context of fusion research are plasma-wall interactions and tritium breeding blankets. TLK was the perfect place to do research on the latter. The actual aim of the Master’s thesis is to design an experiment which proves that tritium extraction from liquid PbLi can be done using the concept of the vacuum sieve tray (VST). In this concept, small PbLi droplets are created in a vacuum tank and when two tritium atoms reach the surface of this droplet, they combine and escape from the droplet in the form of tritium gas. This concept was abandoned in the eighties after calculations had shown that the tritium diffusion from the center of the droplet to the surface was not fast enough and high efficiencies could never be reached in a reasonably sized device. Recent new research showed however that the droplets are oscillating during their fall which enhances the tritium transport to the droplet’s surface and made this concept feasible again.  During last years, some experiments were conducted in Kyoto, Japan using deuterium and liquid PbLi and the results were very promising. TLK has decided to build an experimental set up to try to reproduce these results with tritium and to optimize this technology. My job is to make simulations of the experiment and to use the results to optimize the dimensions and geometry of all components in order to finally arrive to an effective design of the experimental rig. The fact that tritium and liquid PbLi will be used for the experiments introduce some extra challenges which did not occur in the deuterium experiments, e.g. the set up has to be constructed inside a glove box and very strict safety regulations have to be met.

My life in Karlsruhe is very pleasant. All of my colleagues are very friendly and are always prepared to help me with possible issues. Some of them have become my best friends here and I often  see them more during the weekend than during the week! I actually live in Weingarten, a small village situated closer to the north campus of KIT. It is a very peaceful village surrounded by hills and forests but is also very close to Karlsruhe. The park surrounding the castle of Karlsruhe as an amazing place to relax on a sunny day where you always find hundreds of student doing what they like to do. As Karlsruhe accommodates a lot of students - actually maybe too much as finding a suitable and payable accommodation can be very hard -  there are plenty of bars and parties to enjoy during the weekend. KIT is very welcoming towards international students. Being together with e.g. six people and all of them having another nationality is therefore no rarity. All these things make my life very enjoyable and I didn’t regret coming here for a single day!

I really appreciate that FuseNet provided me with some financial support so that I could live this adventure and was able to optimally develop my research skills to one day hopefully return the favor.