The invention involves a novel idea that might improve the extraction of negative ions from an ion source to form ion beams of negative hydrogen ions or other moderately electronegative materials. The principal application would be the production of negative hydrogen ions for use in negative-ion neutral-beam systems used for plasma heating, current drive, and rotation control in magnetic fusion energy devices. A heavy halogen would be added to a hydrogen plasma to induce ion-ion plasma sheath conditions so that a larger fraction of the negative hydrogen ions can be extracted from the ion source due to the much smaller ambipolar potential well in an ion-ion plasma as compared to an ordinary electron-ion plasma.
No.:
M-789
