The tutorial gives insights in the need, challenges and ongoing R&D of powerful and large RF-driven ion sources for extracting the required current of negative hydrogen ions (H- and D-) for fusion:
The neutral beam injection systems for the international fusion experiment ITER (www.iter.org) are based on large negative hydrogen ion sources that have to operate at very ambitious parameters....
A higher density of the negative ion in front of the plasma beam boundary is important to extract a higher beam current density in the negative hydrogen ion source. Negative ions are mainly produced on the surface of the plasma-facing grid electrode (PG) in cesium seeded negative ion source for fusion. The negative ions are produced from positive ions and atoms impinging to the PG surface by...
Neutral beams are a valuable option to provide heat and current drive to a magnetically confined plasma. In addition they can be used as a diagnostics for the positive ion temperature and, in case of nuclear fusion reactions, for the amount of helium ash. In the case of ITER, stringent requirements are set on the acceptable beam divergence and aiming in order to propagate such beams up to the...
Hydrogen negative-ion source is widely used in the field of high energy particle physics and nuclear fusion science, but the extraction mechanism of hydrogen negative-ion, which is produced at the surface of Plasma Grid (PG) of the source, is not clear. Recent experimental analysis on beam phase-space structure suggests that the non-uniform negative-ion density distribution was formed near...
