| 摘要 |
A magnetic immersion lens has inner and outer pole-pieces arranged symmetrically about a longitudinal axis X-X of the lens, the inner pole piece having a through-bore and the lens producing a magnetic imaging field for directing along the through-bore secondary electrons emitted from a specimen positioned in front of the inner pole-piece. The lens has an axially-symmetric detection arrangement located within the through-bore. The detector comprises a focusser electrode, a repeller electrode, an extractor electrode, a detector electrode, and a reflector electrode |
