| 摘要 |
A liquid metal ion source (LMIS) has a reservoir for containing an ion material and an emitter disposed in relation to the reservoir such that molten ion material heated in the reservoir wets the surface of the emitter and flows to the emitter apex. Prior to charging the reservoir with the ion material, the reservoir and emitter are cleaned by a high temperature cleaning operation. For cleaning, the LMIS is placed in a vacuum chamber. A current is applied through the electric feed through terminals to heat the reservoir until it becomes red hot. Then, the emitter is heated by electron bombardment by keeping the emitter voltage at ground potential while applying a high negative voltage to the reservoir. After cleaning, the emitter and reservoir are immersed in a liquid ion material contained in the vacuum chamber and maintained in the molten state by a separate melting unit having a heater. Once the reservoir is filled, a smooth continuous flow of molten ion material is provided to the apex of the emitter for providing a continuous and stable ion emission operation. Also, shields are provided to prevent vapor deposition on the base plate from forming a short circuit between the feed through terminals and the emitter.
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