An introductory course covering SEM theory, components, operation, and specimen preparation techniques.
This document provides a comprehensive overview of scanning electron microscope (SEM) theory and practice. It explains the seven primary operational systems of an SEM—vacuum, beam generation, beam manipulation, beam‑specimen interaction, detection, signal processing, and display/recording—detailing how each contributes to image formation.
The material also describes specimen preparation methods, including sputter coating, critical point drying, freeze drying, and other techniques. Appendices give additional technical considerations and a set of review questions for students to test their understanding.
| Required vacuum pressure | below 10⁻⁴ Torr (typical operation 10⁻⁶ Torr) |
|---|
The SEM must operate at a pressure below 10⁻⁴ Torr, with most instruments running around 10⁻⁶ Torr.
A voltage of about 10 kV is most common for biological or heat‑sensitive samples.