| 摘要 |
PROBLEM TO BE SOLVED: To provide a chopper which can chop a pulse beam whose rise and fall times are short off a temporally continuous beam. SOLUTION: In the charged particle chopper where an entrance electrode (31) and an exit electrode (33) which have central sections that have numerous cavities through which charged particles 1 can pass and one, two or more intermediate electrodes (32) which have central sections that have numerous cavities through which the charged particles 1 can pass are located, the sizes of the cavities are made smaller that of each electrode and the beam is chopped by applying a static potential which is lower than the energy of a charged particle beam to the entrance electrode (31) and the exit electrode (33) and a potential which temporally fluctuates to the intermediate electrodes (32); the external diameters of the intermediate electrodes (32) are smaller than those of the entrance electrode (31) and the exit electrode (33). COPYRIGHT: (C)2006,JPO&NCIPI
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