| 摘要 |
PROBLEM TO BE SOLVED: To reduce the size of a charged particle beam deflector that applies scanning magnetic fields in deflected directions, in both the progress direction of charged particle beams and the direction crossing the progress direction at right angles. SOLUTION: The deflector is provided with an X-axis deflection scanning coil 15 for deflection scanning charged particle beams in the X-axis direction perpendicular to the Z-axis direction where the charged particle beams progress, and a Y-axis deflection scanning coil 16 for deflection scanning charged particle beams in the Y-axis direction perpendicular to the Z-axis and X-axis directions. The X-axis and Y-axis deflection scanning coils are formed with high-temperature superconductive coils without using any yoke, and they are arranged so that the X-axis deflection scanning coil can be located on the outer circumferential side of the Y-axis deflection scanning coil while both coils are positioned within the same plane perpendicular to the Z-axis. Coolers 22, 23, 24 and 25 are provided to cool down the Y-axis and X-axis deflection scanning coils. Alternating current with the frequency of 1 Hz or above is applied to these X- and Y-axis deflection coils for their deflection scanning operation. COPYRIGHT: (C)2008,JPO&INPIT
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