| 摘要 |
PURPOSE:To generate an ion beam of a long life and stability by a method wherein a holding member thermally connected with a reservoir and a needle- shaped member as well electrically heated is formed with a substance having poor affinity with a liquid metal to prevent needless diffusion of the liquid metal. CONSTITUTION:When a heating current is applied to between the stays 12 and 13, the graphite 20 and 21 is heated by electrification to rise to about 400 deg.K- 600 deg.K in temperature. The heat in the graphite 20 and 21 transfers to a needle- shaped member 25 and gallium 22 while gallium in a reservoir transfers stably and continuously to a tip of the needle-shaped member 25. Gallium exudes to an outer surface of the reservoir 23 through thermal diffusion but does not diffuse on a surface of graphite because of its poor affinity with graphite 20 and 21. Accordingly graphite 20 and 21 is always heated up to the required temperature so as to enable to transfer gallium to the tip of the needle-shaped member 25 stably for hours. |
