Posted on: 26th January 2017

Chasing the evil electrons

Cartoon of a runaway electron. (courtesy of EUROfusion)

Runaway electrons: they may be minuscule, but for a fusion device, they can be quite disruptive. So, knowing how to keep them in check ranks high-up in the fusion research agenda. And, this is one of the areas that EUROfusion fellow and IPP scientist Gergely (Geri) Papp works on.

You may remember, from a previous article, how the fascination with science fiction led Geri to fusion research. The path has led him far and he was recently awarded the Karoly Simonyi Memorial Plaque and Prize of the Hungarian Nuclear Society. The award recognises Geri’s work “in the field of fusion plasma physics, in particular runaway electron research.”

So why is a runway electron such an unwanted feature in fusion research? Geri explains that if a runaway electron beam forms during a fusion experiment, it has the possibility to seriously damage what are known as in-vessel components, e.g., wall tiles, diagnostics, and coolant pipes of the fusion device. “The runaway beam carries a significant amount of magnetic and kinetic energy, and if this beam hits the wall that can lead to large localized heat loads,” he points out. “Either we need a disruption scenario where the beam does not form, or if it is formed we need a way to suppress it before it could cause localized heat loads,” he says. Geri and his colleagues in the fusion community work on both these approaches.

Background about the EUROfusion Researcher Fellowships

EUROfusion Researcher Fellowships, which are part of EUROfusion’s training and education initiatives, are designed to nurture the next generation of fusion experts. And, each year approximately 30 engineers and scientists are selected for receiving the grants through the EUROfusion Researcher Grants and the EUROfusion Engineering Grants programmes..