Accueil du site > Groupes de recherche > Groupe de Recherche Energétique, Plasmas et Hors Equilibre > Projets en cours > Sources d’ions négatifs pour le faisceau de neutres d’ITER
Negative ion source for the ITER neutral beam
11 janvier 2008
G. Hagelaar, G. Fubiani, S. Kolev, L. Garrigues, L. Pitchford, J.P. Bœuf
Heating of the plasma by injection of a fast neutral beam will play a critical role in the ITER fusion project. The neutral beam is generated by neutralisation of a negative ion beam pre-accelerated to 1 MeV, with a current density higher than 200 A/m2 at about 0.4 Pa.
GREPHE is involved in the study and modeling of an RF inductively coupled plasma source, and this will be carried out in close collaboration with experimental collaborators. In order to produce a high flux beam of high energy neutrals, negative ions produced in the plasma and are accelerated before being neutralized and then injected into the plasma in ITER. The conventional low-pressure arc sources are not suitable for conditions in ITER because of the short lifetime of the filaments used in these sources and their unacceptably high maintenance cost. It is for these reasons that RF inductively coupled plasma sources have been proposed. The physics of these sources is complex and many different, interconnected phenomena come into play :
non-collisional electron heating in the inductive source
charge particle transport in the magnetized region
plasma chemistry of the deuterium plasma leading to the volume generation of negative ions or generation of ions on a cesium coated surface
magnetic filtering of electrons for separating spatially the "hot" and "cold" electrons
negative ion extraction from the plasma
