Volume produced H-, D- ion source for proton accelerator and thermo-nuclear fusion research by sheet plasma, (1)

In order to apply a sheet plasma type of volume produced H-, D- ion source to injection of proton accelerators and neutral beam injection of thermo-nuclear fusion researches, a large sheet plasma of width 20 ∼ 25 cm and length 30 cm is produced in the discharge current of 175 A, H2 or D2 gas pressure of about 2.5 x 10-3 Torr and gas flow of (2.0 ∼ 2.5) Torr l/sec in magnetic field of (60 ∼ 110) gauss. Thus, H- or D- ion currents are extracted in current densities up to 19 mA/cm2 or 16 mA respectively, which are uniform within 10 % over the large area (above 250 cm2) of the sheet plasma surface, and for the acceleration voltage up to 4.5 kV. Electron current accelerated with H- or D- ions becomes neglisible beyond a distance of 2 cm from the final acceleration electrode. (author)