| 摘要 |
PURPOSE:To aim at reduction in trouble for axial alignment and improvement in accuracy, by setting up a drawing out electrode, an aperture, an ion beam accelerating voltage and a resistance heating current introducing plate spring all in a vacuum vessel, and melting an ion source metal by means of a resistance heating system. CONSTITUTION:An ion source body 11 is provided with an emitter chip 1, a crucible 2, a crucible holder 10 and a resistance heating electrode 4, and this ion source body is also provided with insulators 6' and 6'' and conductivity preventing caps 7' and 7''. The body 11 is attached to a vacuum vessel part, assembling an ion source, and minute axial alignment is carried out by an electric signal or the like. Vacuum is all kept up by a gasket of copper or the like, and heating of the crucible 2 and melting of an ion source metal are carried out by means of a resistance heating system. The resistance heating electrode 4 is composed of a high-melting point metal, making it close to the crucible 2, while an ion beam accelerating voltage is introduced by a voltage introducing terminal 9 from the outside. With this constitution, assembly/ disassembly and axial alignment for the ion source are all made ever so easy.
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