| Popis: |
Experiments on the production of negative hydrogen ions via surface conversion for incident positive hydrogen ion currents in the range of 0.2 to 1 A/cm2 are reported. The conversion efficiency, i.e. the ratio of the produced negative ion current and the positive ion current on the converter shows a strong temperature dependence and has a maximum for a positive ion current density of about 0.5 A/cm2. Due to the limited magnetic confinement of the intense hydrogen plasma, the base pressure of these experiments was of the order of 50 mTorr which resulted in very large losses of negative ions due to stripping. With correction for these losses, we obtained a conversion efficiency, of the order of 8 percent which corresponds to a surface produced negative ion current density of the order of 60 mA/cmh.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
