Advanced Materials Characterization Chapter 3 Light Electron and Ion Beam Optics

Advanced Materials Characterization Chapter 3 - by Igor Bello

Electron and ion beam optics includes electrostatic and magnetic lenses, apertures, and compensation elements for reducing optical imperfections. Lenses in light and electron microscopes and other analytical instruments that use electron and ion beams tend to focus beams to focal points. However, due to some optical defects, beams of light or particle rays (electrons, ions) are rather distributed over areas with different and characteristic shapes in focal planes that yield diffused and distorted images of observed objects. These imperfections, known as aberrations, affect the resolution of analytical images. The type of aberrations , are recognized based on their shapes. Their presence can also be deduced from reducing the sharpness of object edges with increasing magnification.