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FuseNet PhD event 2014

I just returned home from the fourth annual FuseNet PhD event, organized at IST this year in Lisbon. I presented a poster about some planned future laser-plasma experiments and heard the latest developments by other PhD students working in fusion-related fields. The conference was also a good chance to catch up and network with my peers.

Upon arrival, we were given a sort of physics scavenger hunt around the city. We had to measure an area on the ground, the size of tall buildings using just a laser pointer and so on... To this end, we adopted me as a standard unit of measurement - knowing my height in metres, we were able to use trigonometry and pacing to work out what we needed. I also managed to win a bottle of champagne for another "task".

Unfortunately, I felt that the organization of the conference was very sub-par this year. We were often left standing in the rain, because we were given the wrong timing or hadn't been told where to go. Despite assurances by the organisers, my friend with specific dietary requirements was left with nothing to eat and the list goes on. I understand that the conference had to be put together very quickly and on a tight budget, but it was still very haphazard. Also, I felt that the talks given by academics were at a fairly low level, for what is really a very technical audience.

It became even more clear that Inertial Confinement Fusion is poorly represented in FuseNet, and in Europe in general. While, to be honest, I do believe that Magnetic Confinement Fusion is likely to deliver the first serious reactor concept, I'd like to state for my colleagues the long-term case for ICF:

  • Inertial confinement allows a much wider parameter space (temperature, pressure) to be explored. The magnetic pressure inside a tokamak or stellarator is limited by the strength of superconducting magnets, whose limit is difficult to raise. By comparison, the compression of a capsule is limited by the frequency and intensity of lasers (or currents in z-pinch devices), and both of these technological properties are growing exponentially. Such extremes may make reactions other than Deuterium-Tritium more viable.
  • The divertor, which is unique to tokamaks and stellarators, is the Achilles' heel of MCF designs, with a disproportionately huge heat flux on a tiny area. I believe that a serious long-term fusion reactor must have plasma-facing walls made of liquid; I think it is inconceivable that a solid material would survive the harsh conditions of plasma, particles and neutrons intact. Most likely this liquid would also be a metal such as Lithium. This would present a problem to any magnetic scheme, because a conducting liquid in a magnetic field would be highly unstable; inertial fusion does not have this problem.

Finally, I'd like to recommend the recent film "Interstellar" to anyone working in fusion. In the film, humanity must solve a long term physics and engineering challenge to survive - very poetically similar to our work.

Photo: Poster presentation and bottle of champagne before being shared with colleagues.