The International Atomic Energy Agency this year held its biennial Fusion Energy Conference (FEC), often cited as the “main” conference on fusion, in the Palais des Nations in Geneva, Switzerland. The FEC always provides a good opportunity to review the status of fusion research in the world. 50 years ago the same building hosted the historical 2nd International Conference on the Peaceful Uses of Atomic Energy, where leading countries in fusion research revealed their program and opened the way to fruitful international collaboration.

And indeed, 50 years later, the most striking feature of the 22nd FEC was the success of this international collaboration, which resulted in tremendous scientific and technical progress. This is clearly shown by statistics: the 22nd FEC was attended by 761 participants from 42 countries; the contributions included 116 oral presentations and 507 posters. In a special evening session the conference organizers celebrated the anniversary by looking back on the history of 50 years of magnetic confinement fusion research.

Another striking feature of the conference was that ITER, the embodiment of international cooperation on fusion, has started providing a powerful drive for physics and technology R&D all over the world. The vast majority of tokamak results presented at the conference aim at supporting ITER design choices, developing modes of plasma operation applicable on ITER or addressing ITER relevant physics issues.

The status of ITER was presented in various talks. An update on the project’s progress including the ongoing site preparation, the outcome of the Design Review and the impacts the technical updates will have on the ITER baseline design were introduced.

Key tests in the preparation of ITER construction were reported on, including: the Nb-Ti and Nb3-Sn conductors required for the large superconducting coils have been qualified with adequate margins; a world record was obtained with a Japanese gyrotron operating at 170 GHz, 1MW, 800s, reaching ITER specifications except for the pulse duration (3600s); ITER-like antenna concepts are being successfully tested on Tore Supra (France) and JET (EU). Important progress was also reported on prototyping in preparation for the construction of the Divertor, First-Wall, Shielding Blanket, Vacuum Vessel and Cryopump.

Several tokamaks were reported as demonstrating plasmas that meet ITER requirements, although more work is required towards a full set of ITER-like operating conditions. In particular performance with metal walls to reduce erosion and fuel retention looks promising (the first full tungsten wall was recently experienced on ASDEX-Upgrade, Germany), but more work needs to be done. The ITER-like wall experiment in preparation at JET is expected to play a crucial role in the next few years.

Steady-state operation has seen significant advances, with fully non-inductive operation of tokamaks, but issues remain for long pulse operation, in particular with localized heat/particle handling and heating systems technologies. New superconducting tokamaks have started operation recently, EAST in China (first plasma in September 2006) and KSTAR in Korea (first plasma in June 2008). This latest is the first tokamak using Nb3Sn superconducting coils as planned for ITER.

Transport of particles, heat or momentum, remains a key topic related to the performance of magnetic confinement devices. Theory-based models for particle transport have seen progress and experimental validation. Clear evidence of critical temperature gradient was demonstrated; the evidence of zonal flows (phenomena in fusion plasmas reducing turbulent transport, thus improving thermal insulation) is growing. Worldwide work on heat and particle transport was reported to confirm former predictions of ITER performance. Significant efforts are now targeting the description of momentum transport in the plasma.

Progress has been achieved to avoid or mitigate transient events, with, in particular, an increased level of confidence in controlling and mitigating such events on ITER, supported by experiments (e.g. DIII-D, US and JET, EU), theoretical analysis and modelling. Real time control of magnetohydrodynamics (MHD) instabilities has seen further advances, which should increase operational margins and allow normalized plasma pressure operation above ITER requirements.

The stellarators research line is also progressing steadily, with the superconducting helical device LHD, Japan, operating in nearly 1/4 hour pulses and exploring ways towards high plasma pressure operation. The superconducting stellarator W7-X (Germany) construction is on good track, with first plasma foreseen in 2014.

Inertial fusion results were also presented at the conference. In the US the National Ignition Facility (NIF) is almost completed with 4.2 MJ laser obtained in September 2008. The first deuteriumtritium experiments are fore-seen in 2010, and high gain G ~ 10-20 (G = fusion energy/laser energy to target) experiments foreseen a few years later.

The Fast Ignition Scheme is progressing steadily with several experimental and theoretical projects reported; compared to the direct drive technique, this approach drastically reduces the requirements in terms of laser energy required to bring the target to ignite. “Sub-ignition” experiments will start soon on the facilities in the US (OMEGA-EP) and Japan (LFEX). The fast ignition concept will be tested with 10-30 kJ lasers for compression and ~5kJ lasers for heating. Future highgain experiments are projected in Japan (FIREX II) and Europe (HIPER).

New image film on fusion honoured The film, “Energy of the Future. Fusion 2100”, produced by IPP on behalf of EFDA, was presented with the Future Award 2008 at Photokina, the leading international fair of the imaging branch. The prize was conferred by the German section of the Integrated TV & Video Association (ITVA) to mark its 25th anniversary. At a gala evening the President of the Association for Audiovisual Communication, Dr. Gerhard Dotzler, presented the award to film producer Klaus Naumann and IPP’s Julia Sieber.

Isabella Milch