Divertor research: A “hot fusion topic”, not just for early stagers

To Robert Abernethy it’s nothing less than rocket science. The materials student from the University of Oxford has recently organised the first divertor workshop for students. He chose the divertor, the “ashtray” of the tokamak, as a topic, because he finds it “the most challenging area in a fusion device”. The participants of this year’s European Student Divertor Research Workshop came from various disciplines -a fact which is crucial for Abernethy to solve the different challenges in fusion.

What is so interesting about the divertor?

It could be one of the biggest tasks to be solved within fusion science. We haven’t yet seen a similar environment on Earth. The heat fluxes there are like those in a rocket engine; the neutron flux is so intense that we cannot reproduce it in experiments. This all just leads to a special material development that we just don’t see elsewhere. And of course, my research into tungsten, the material which is used for harsh conditions, has motivated me to organise this workshop.

The goal of your workshop was to connect European students from different academic backgrounds. Why?

Fusion is, by its very nature, a challenge that crosses many disciplines. Getting people with a variety of specialisations together in the early stages of their career was very helpful for the success of the event. Indeed, we managed to bring together 19 people from ten European institutions. Fusion is a long term challenge. I hope the workshop has set up collaborations which turn out to be fruitful over the next few years. Unfortunately, there are not enough meetings like this taking place.

Robert Abernethy (24) from Liverpool is currently pursuing his PhD at the University of Oxford. He is interested in radiation damage in tungsten. He loves to explore material behaviour while using state-of-the-art-equipment: “Researching this within the fusion community makes my work all the more interesting and enjoyable, thanks to working alongside intelligent and hardworking researchers across a range of fields.” Picture: private

Robert Abernethy (24) from Liverpool is currently pursuing his PhD at the University of Oxford. He is interested in radiation damage in tungsten. He loves to explore material behaviour while using state-of-the-art-equipment: “Researching this within the fusion community makes my work all the more interesting and enjoyable, thanks to working alongside intelligent and hardworking researchers across a range of fields.” Picture: private

What do you mean?

As a scientist starting out on your career, you would like to receive feedback and practice. Of course, it’s great to hear the big speakers presenting at the conferences but you will rarely have the opportunity to get in touch with them and have the chance to ask particular questions. For instance, by inviting Tilman Lunt (IPP Garching) and Tom Barrett (CCFE) we offered the participants a way of engaging them in individual talks. It was also motivating to hear about the work being carried out for the new upper ASDEX-Upgrade divertor or the challenges in engineering a tungsten divertor. Moreover, it turned out to be quite significant to have an engineer and a material experts discussing the same topic. You don’t see that very often in conferences.

Are you planning another divertor workshop next year?

I hope so. We have managed to establish a network and I am asking around to find out whether someone would be interested in hosting the next event. It would be great to hold it at a facility which enables us to directly study the divertor, thus a facility with a fusion device.

Do you have any special facility in mind?

I would be very interested in visiting the Swiss Tokamak à Configuration Variable (TCV). It provides the most flexibility for implementing the different divertor concepts. I am curious to see what’s going on there and what looks the most promising.

Plasma Exhaust

Robert is right. The divertor is a “hot topic” in fusion research. Improving divertor designs is one of the main targets of EUROfusion’s research. Mission 2 of the European fusion roadmap prioritises the so called ‘Heat-exhaust systems’. The outcome should result in magnetic configurations that will reduce the heat loads and ensure the use of divertor materials capable of handling them. EUROfusion has launched a call this year to fill the gap in plasma exhaust research. The consortium is currently deciding on about ten proposals which cover conventional or alternative divertors, as well as conventional materials and plasma facing units and advanced materials.