| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid-metal ion source which can generate a stable ion beam maintained for a long time. SOLUTION: In this liquid-metal ion source, a needle-like member 4, of which one tip portion is formed in needle shape and passes through a small hole 2 and the other end portion is fixed to the side surface of a reservoir 1, is disposed in the reservoir 1 in which liquid-metal 3 is contained. Also filaments 6 fixed on the side surface of the reservoir 1 are supplied with a heating current through terminals 8, supported by an insulating supporting 7, from a power source or heating 9. A power source for extraction 12 applies a positive high voltage for extraction between an extracting electrode 20 and the needle-like member 4. A power source for acceleration 13 applied a positive high voltage for acceleration between a cathode electrode 21 and the needle-like member 4. Here, base body 20A of the extracting electrode 20 and base body 21A of the cathode electrode 21 are made of stainless steel, and tungsten layers 20B, 21B are formed on the respective surfaces of the base bodies 20, 21 facing the tip portion of the needle-like member 4.
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