| 摘要 |
PROBLEM TO BE SOLVED: To provide a particle optical device with magnetic means, which reduces and/or stabilizes heat generation in coil and reduces heat transfer from the coil to a polar plate.SOLUTION: A particle optical device comprises magnetic means having a particle source for generating at least one charged particle beam and two polar plates, where the polar plates are disposed mutually spaced apart so that a charged particle passes through the polar plates at the time of operation, a groove 21e is provided on the polar plates 25e, and coil wire 26e is arranged in the groove 21e. When viewed from a cross section relative to an extending direction of the groove 21e, the groove 21e has width B1 in a surface area of the polar plate 25e narrower than width B2 in an area spaced apart from a surface 34e. |
