Fusion Science and Technology / Volume 46 / Number 2 / September 2004 / Pages 271-278
Technical Papers / Stellarators
Energy-resolved neutral particle fluxes are studied in the TJ-II stellarator by using measurements from a neutral particle analyzer. The average ion energy can be deduced up to positions outside the last closed magnetic surface because of an upgrade of the diagnostic. The results suggest that the average ion energy profile is flat, even at positions outside the last closed magnetic surface, which implies the existence of hot ions well outside the plasma. Such a flat profile may be related to wide ion orbits connecting distant areas of the plasma.