PLATUN (Plasma Turbulence - Neutrals interaction in the edge of tokamaks)

Research on magnetic controlled fusion aims at using nuclear fusion of two isotopes of hydrogen, like in the sun, to produce energy. This reaction indeed releases ten time as much energy as the fission of uranium but poses more technical difficulties, such as the confinement of a plasma heaten in its inner part to more than ten millions degrees.

Significant progress has been made over the past twenty years and ITER, a tokamak that will be commissioned by the end of the decade, is prepared to demonstrate that this industry is likely to give to humanity an energy source that would be controllable, little polluting and secure.

One of the remaining difficulties is the way the energy produced by fusion reactions is transmitted to the walls that directly face the plasma. For ITER, energy flux density due to collision of particles from the plasma on those walls would be far beyond what the highest performance material would stand.

Neutral atoms, naturally present at the edge of the plasma or injected are the key ingredient to lessen that flux density. These are collided by high energy particles from the plasma that subsequently loose kinetic energy, while neutral atoms scatter that energy by radiation on a much larger surface, which results into relieving of plasma facing components. Neutral dynamics in tokamak near-wall region is then an important question. It was shown that it is linked to edge plasma turbulence. Coupling neutral dynamics and edge plasma turbulence is quite challenging for physicists performing numerical simulations.

This project aims to meet this challenge, with the help of experimental means from IJL, as its fast visible cameras (1 million frames per second) and its future SPEKTRE platform, that will make it possible to check results from numerical simulations on experiments, as well as already existing theoretical models.