| 摘要 |
A source (100, 101, 200, 300, 400) of a beam of positive ions or atoms comprises an ion-emission pellet (1, 401) consisting essentially of a solid electrolyte. Preferred solid electrolytes for the pellet (10, 49) are alkali or alkali-earth mordenites. A pellet heater is capable of heating the pellet (1, 401) to an ion-emission temperature at which ions are emitted from the pellet. A beam-forming electrode (2, 4, 31, 60) contacts an ion-emission surface (22) of the pellet (1, 401). The beat-forming electrode (2, 4,31, 60) has at least one passageway extending through it into which ions from the ion-emission surface (22) can pass. Ions emitted into the passageway are discharged from the source as unneutralized ions or neutralized atoms. The ion-emission surface (22) of the pellet (1) may optionally be coated with a layer (2, 31) of porous tungsten or other refractory, high-work-function material to establish an essentially equal potential across the surface (22) and to neutralize ions emitted from the surface (22) when the source (101, 300) is operated as an atom source.
|
