The way towards thermonuclear fusion simulators

In parallel to the ITER project itself, many initiatives address complementary technological issues relevant to a fusion reactor, as well as many remaining scientific issues. One of the next decade's scientific challenges consists of merging the scientific knowledge accumulated during the past 40 years into a reliable set of validated simulation tools, accessible and useful for ITER prediction and interpretation activity, as well as for the conceptual design of the future reactors. Obviously such simulators involve a high degree of “integration” in several respects: integration of multi-space, multi-scale (time and space) physics, integration of physics and technology models, inter-discipline integration etc. This very distinctive feature, in the framework of a rather long term and world-wide activity, constrains strongly the choices to be made at all levels of developments. A European task force on integrated tokamak modelling has been activated with the long-term aim of providing the EU with a set of codes necessary for preparing and analysing future ITER discharges, with the highest degree of flexibility and reliability. In parallel with the development of simulation tools and software environment, the long term evolution of hardware needs is also discussed at several levels (EU, EU–Japan broader approach, high performance computing, grid technology, data access, etc.), and progress in this domain is reported. Finally, the ITM task force is also working out the worldwide compatibility through regular collaboration with the similar integrated modelling structures which already exist or are being put in place by the other ITER partners.