I took an extended week-end to recover from the particularly busy month of June, a week-end far away from plasma physics and fusion research. But I was not finished with the summary from last week’s EPS conference in Strasbourg. This is the story of the second part of the conference.
The thursday’s session had a taste of AIAA conference with a talk on reentry plasmas (more generally on kinetics in molecular gases) by Capitelli and one on plasma space propulsion. I must admit that I did not completely follow the logic behind the presentation, it was a bit too fast for me; if someone has some complements, or an easy way to develop the presentation, he is welcome . I saw that there was a big consortium called Phys4entry organised for the 7th framework program of the european union. I should write a post on the issue of this FP: look at the list of participants and tell me how many they are: a lot, indeed! I would like that somebody from the EU explain me how to manage with limited funding so many interfaces between big companies, labs and startups. But this is another story.
The second talk on plasma thrusters, by E. Ahedo, had my full attention: the presentation of the requirements for space engines was good, with highlights on the two main drivers: specific impulse and thrust and the trade-off to do to achieve mission objectives. I was a bit disappointed by the presentation of the different types of thrusters. It was more an enumeration of the technical specs of each engine than an explanation of their principle. I think he should have narrowed the scope of its talk and focused on a small number of systems, for instance the Hall thruster and the Vasimr engine, which really have a lot of common parts with auxiliary systems for tokamaks and stellerators (helicon source like in NBI, ICRF heating…). But well, he had a stringent time limit. Anyway, there also were some posters on the topic of helicon sources which have applications for these space thrusters.
We had again a full series of talks on transport (ok it is normal, it is issue #1), with ion heat transport on JET, and a special emphasis on the effect of plasma rotation. A particular noteworthy presentation concerned the I mode on Alcator C-Mod and ASDEX Upgrade by Hubbard. The I mode is an intermediate mode between the Low confinement mode and the High confinement mode, the famous H-mode. In the I mode, we have an independent control of energy and particle confinement, with a pedestal in Te and Ti but without density barrier: the energy is confinement but the particles not and fusion ashes can be swept out without extinguishing the reaction.
On the last day of the conference, we had a contact between two worlds: the world of plasma physics and the world of medicine,, with a presentation on synergistic effects in plasma-surface interactions by D. Graves and on application of non-equilibrium plasma by G. Kroesen. I won’t go into the details but the main idea is that a plasma is created in the air at the interface with the skin; the plasma enhances some specific chemical reactions which can help, for instance, to treat wounds (with some nice pictures of them at 8.30, the day after the conference dinner!). I have a lot admiration for these people who create bridges between two continents of science: this requires to be open-minded, self-confident and of course a bit crazy.
I followed, to finish, the parallel sessions dedicated to magnetic confinement fusion, to have a look at the numerical tools used to design and develop the plasma scenarii for ITER (by G. Giruzzi), with codes like CRONOS, METIS, HELIOS. The purpose is to develop scenarios with a strongly enhanced level of self-organization, with self-heating, Alfven eigenmodes and high bootstrap current. Well each time, I hear the phrase “self-organization”, I do not make a connection with tokamaks but with spheromaks.
Some other talks on current ramp on MAST and on current overshoot on ASDEX Upgrade to reach the improved H-mode were among the last noticeable talk I would like to mention.
All in all, an interesting conference which makes it possible thanks to a great effort of communication to discover new areas of research. The big topic is transport driven by turbulence in tokamaks, with a subsection related to rotation. ASDEX Upgrade was very present with the use of RMF coils for the first time and it was the only big tokamak in Europe in operation last year. People from CCFE had also very good talks, well prepared, cleared, proving once again the seriousness of this reference in scientific research.
I hope that I gave to people who were not present a feeling of the content of this conference and if you have some questions or comments, please do not hesitate.