| 摘要 |
PURPOSE:To form a spiral groove in the conical portion of an emitter chip by spirally winding up an electrode wire on the conical portion of the emitter chip, and immersing the conical portion into an electrolytic solution to electropolish an emitter chip material. CONSTITUTION:An emitter chip 1 which is used in a needle type liquid metal ion source is formed to have a spiral groove in the conical tip portion of the emitter chip, and the heating effect due to a filament is improved and the flow of an ionization material is made good. At this time, an extremely fine electrode wire 2 is wound to allow it to approach 1mm or less in the periphery of the conical tip portion of the emitter chip 1, and the conical tip portion is immersed into an electrolytic solution 4 such as the aqueous solution of caustic soda or the like to electropolish it. And an electric field is concentrated on the portion near the electrode wire 2 of the conical portion to form a groove corresponding to the shape of the electrode wire 2. Accordingly, it is possible to easily and accurately form desired groove, and to obtain a stable ion beam. |
