| 摘要 |
PROBLEM TO BE SOLVED: To avoid a non-uniform distribution of dose in the Y direction of electron beams projected onto an irradiation object by enabling the prediction of breaking of a filament. SOLUTION: A pair of first power feed conductors 14a are installed in parallel in the X direction. A plurality of first filaments 12a supported by the first power feed conductors 14a are installed in parallel in the Y direction. A filament power source 34 feeds an electric current to the first filaments 12a. Thermions emitted from the first filaments 12a are projected onto the irradiation object as the electron beams. A second power feed conductor 14b is installed between the first power feed conductors 14a and the filament power source 34. Two resistors 30 are individually connected aross the pair of first power feed conductors 14a and the pair of second power feed conductors 14b. A second filament 12b supported by the pair of second power feed conductors 14b is installed on the position located outward of an irradiation window 6 in the Y direction. COPYRIGHT: (C)2007,JPO&INPIT
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