Development of hydrogen ionic plasma source with superimposed positive-ion beam.

A hydrogen ionic plasma source has been developed that is with a low residual electron presence (<0.01) using an aluminum plasma grid for negative hydrogen ion production and a control grid for electron removal. The ionic plasma density increases when a positive-ion beam is superimposed on a hydrogen plasma and irradiated onto the Al plasma grid. Even though the ionic plasma is formed in a region with high-deflection magnetic flux density, a collapse phenomenon can occur downstream of the region under certain electrode voltage conditions, causing electrons to appear and forming an electron plasma. Under electrode voltage conditions that prevent the collapse, the nine ionic plasmas, each passing through extraction apertures with a diameter of 1.3 cm, are combined to form the ionic plasma with a diameter of approximately 6 cm and a density on the order of 10 9 cm−3. [ABSTRACT FROM AUTHOR]