(c) CEA

The facts & the project

Will nuclear fusion, a natural reaction occurring in the Sun and the stars in the Universe, be the future of energy supplies on the Earth? A result of a massive international collaboration, the ITER(International Thermonuclear Experimental Reactor) facility, currently under construction in Cadarache, should provide an answer within the next ten years. In the meantime scientists are refining their understanding of the physical phenomena involved and high performance computing is playing a dominant role in this.

This is the case with the team of Yanick Sarazin (CEA), which is attempting to predict heat losses associated with the turbulence which develops in the plasma. In reactors like ITER, the fusion reaction is achieved by confining a very hot plasma by means of an intense magnetic field. The greater the heat losses, the longer the time in confinement that is required to achieve a self-sustaining reaction.

The resultats

Thanks to the ab initio simulations carried out using the GYSELA code on GENCI’s Turing supercomputer at Idris (20 million hours), the researchers demonstrated that the turbulence was able to regulate itself by generating flows of the order of the size of the machine, which effectively stabilised it, thus limiting the heat losses.

This unexpected property, subsequently confirmed experimentally, would seem to offer considerable possibilities in controlling fusion reactions, provided that the self-organisation of the turbulence is managed.

This work is continuing into 2015.