| 摘要 |
<p>In the magnetic optical system of a transmission electron microscope (TEM), the increased strength of a second objective lens (14) is used to increase the longitudinal energy dispersion by forming an image at a magnified second back-focal plane. The electric current distribution of other lenses (6, 18) in the microscope is reconfigured to compensate for any offsets introduced by the modified second objective lens (14). A plurality of deflectors (16) are installed which enable the manipulation of the electron beam electronically between the specimen and the second back-focal plane. The magnified second back-focal plane is projected onto the selected-area aperture (12), allowing the use of the existing selected-area aperture (12) as an objective aperture to achieve an energy filtering effect which improves the image contrast and resolution.</p> |
