Modelling the ion source for ITER NBI: from the generation of negative hydrogen ions to their extraction

D Wünderlich, S Mochalskyy, U Fantz, P Franzen
2014 Plasma Sources Science & Technology  
The neutral beam injection system for ITER is based on a large (A source = 1.9 × 0.9 m 2 ) negative hydrogen or deuterium ion source. In this source negative ions are produced in a low-pressure (p fill ≈ 0.3 Pa) plasma by conversion of atoms and protons on a caesiated molybdenum surface with low work function. Then the negative ions are transported through the plasma to the extraction system where extraction of these ions and also co-extraction of electrons take place. This paper describes the
more » ... aper describes the status of the modeling activities connected with the negative ion test facilities of IPP Garching. It is illustrated that these modelling activities constitute a strong support of the experimental activities connected with the development of the negative ion source for ITER NBI. Several numerical codes developed in the past years -in close collaboration with the experiment -and their results are introduced. Focus is laid on the production, transport and extraction of negative hydrogen ions and on the inevitable co-extraction of electrons.
doi:10.1088/0963-0252/23/1/015008 fatcat:xjgwm3ciifc3tg4l4lajfsknhi