Large-Area, High-Transparency Extraction System for Negative Ions

In the frame of a collaboration between CEA Cadarache and IPP Garching investigations have been carried out to extract negative hydrogen ions from a large-area rf source (32 x 61 x 19 cm 3 ) by using a medium-size extraction system of 69 cm 2 with 45 holes. To demonstrate the plasma uniformity of the rf-source a large-area extraction system has been designed and is under manufacturing now.