| 摘要 |
<p>Electrons in orbits close to the optical axis (9) of a primary beam (2) and electrons in more external orbits are separately detected with a simple configuration. This is achieved by an electron detecting mechanism having a plate (5) provided with an opening (4) permitting passage of the primary beam (2), an energy filter (3), a first light detector (7a), and a second light detector (7b). The plate (5) has first and second scintillating surface on its opposite sides. The first scintillating surface faces a sample (10). The second scintillating surface faces the energy filter (3). When the primary beam hits the sample (10), electrons are produced and some of them impinge as first electrons (21) on the first scintillating surface. Consequently, first scintillation light is produced and detected by the first light detector (7a). At the same time, some of the electrons produced from the sample (10) pass through the opening of the plate, are repelled by the energy filter (3), and impinge as second electrons (22) on the second scintillating surface. As a result, second scintillation light is produced and detected by the second light detector (7b).</p> |
