[new term] primary beam
Came across 2-gram term "primary beam" in automated n-gram analysis of EM textbooks. For example, see:
- "Using a small energy slit, the primary beam energy of the filtered pattern is selected at different radii from the optical axis ..."
- "Dark-field contrast is obtained by tilting the primary beam or by hollow-cone illumination so that the primary beam falls on the objective diaphragm."
- "By using the primary beam in the bright-field mode or a Bragg-reflected beam in the dark-field mode, ..."
Also see e.g. https://www.iso.org/obp/ui/#iso:std:iso:15932:ed-1:v1:en (Microbeam analysis — Analytical electron microscopy — Vocabulary)
- 8.5.4
- extinction distance
- periodicity in depth of the electron intensity oscillation between the primary beam and the Bragg reflected beam
Also see https://www.iso.org/obp/ui/#iso:std:iso:23833:ed-2:v1:en (Microbeam analysis — Electron probe microanalysis (EPMA) — Vocabulary)
- 3.3.8
- secondary electron
- Electron emitted from the specimen as a result of inelastic scattering of the primary beam electron by loosely bound valence-level electrons of the specimen
- Note 1 to entry: Secondary electrons have conventionally an energy less than 50 eV.