| 摘要 |
<p>A magnetic electron lens which is analogous to a concave optical lens and usable in charged-particle beam applied apparatuses such as an electron microscope. The magnetic concave lens comprises a first and a second coil (2, 3) for generating magnetic fields, which are made of a superconductor and are arranged in the direction of the travelling of the charged particle beam, and a first and a second magnetic shielding plate (1, 4) which are so provided as to surround the upper side of the first coil and the lower side of the second coil respectively. By the first magnetic shielding plate (1), the magnetic field generated on the upper side of the first coil (2) is blocked. Similarly by the second one (4), the magnetic field generated on the lower side of the second coil (3) is blocked.</p> |
