| 摘要 |
PURPOSE:To generate stable ion beam for a long period of time by providing a heating means which heats a reservoir to which substance to be ionized is reserved, a pair of leadout electrodes attached to the end of reservoir and a means for causing electron beams to collide with the end of reservoir. CONSTITUTION:A heater 12 is uniformly wound around a reservoir 1 in which substance 4 to be ionized is reserved and the heater 12 is heated by a power source 13. A temperature of reservoir 1 is measured, for example, by a thermocouple 14 and a voltmeter 15 and is kept at the specified value in accordance with a kind of substance 4 through the feedback to the power source 13. A plug 16 hermetically seals the reservoir 1, except for a fine hole 3. When the temperature reservoir 1 reaches the preset value, an acceleration voltage and leadout voltage are applied to each electrode from the acceleration voltage source 10 and leadout voltage source 11 and moreover the filament 7 is heated by the filament voltage source not shown in the figure. Thereby, the end 2 of reservoir 1 is excited by electrons. The electron beam generated from the filament 7 is concentrated to the end portion 2 and thereby the ion beam in a heavy current can be stably obtained at the leadout electrode 5. |
