シートプラズマによる大電流H^-, D^-イオン源の研究 (I)

抄録

H^- ions with a current density of about 30 mA/cm² (2.1 mA in 3 mmφ) or D^- ions with about 8 mA/cm² (0.56 mA in 3 mmφ) near an energy of 2.5 keV, is extracted from outside of a sheet plasma around a low pressure 7.7×10^-4 Torr and a weak magnetic field 100 gauss. The sheet plasma (14 cm width and 0.8 cm thickness) produces a large uniform diffusion flux of plasma over a large area across the magnetic field, and includes electron beam components (50 eV) in it's center while the electron temperature outside of the sheet plasma is ranging from 2 eV to 3 eV. An effective extraction method in which only H^- or D^- ions are focussed and electrons are deviated, is found while the electron current is suppressed below 1/5 compared with the H^- or D^- ion current.