| 摘要 |
PURPOSE:To carry out high efficient drawing-out for an ion beam, by installing a porous plate in an outlet of an ionization chamber, while installing a workpiece body as opposed to this porous plate in the outside of the ionization chamber, and impressing an electric field between the plate and the workpiece body. CONSTITUTION:A porous plate 22 is installed in an outlet of an ionization chamber 2. A workpiece 16 is installed as opposed to the plate 22 in the outside of the ionization chamber 2. And, such an electric field that draws ions out of the ionization chamber 2 and accelerates them by a power source 26 is impressed between the plate 22 and the workpiece 16. The degree of divergence of an ion beam impinging on the workpiece 16 is adjustable by the condition of oozing of plasma through the late 22, and adjustment for the oozing condition of the plasma can be done by changing an ion drawing voltage V and a distance L between the plate 22 and the workpiece 26. Thus, high efficient drawing out for an ion beam can be performed.
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