3 Product and Functional Description | 3.2 Main Components
ZEISS
3.2.2 Electron Optical Column | Gemini I
Purpose
The GEMINI I column is the part of the microscope, where electrons are emitted, accelerated, de-
flected, focused, and scanned. Main characteristics of the GEMINI optics are the beam booster
and an objective lens that consists of a combined electrostatic/electromagnetic lens doublet.
U
EHT
U
Ext
U
Sup
U
B
2
1
3
4
5
6
7
8
9
Fig. 9: Schematics of the electron optics
1
Gun
2
Extractor
Positive electrode that extracts electrons from the filament.
3
Anode aperture
4
Multihole aperture (aperture changer)
5
Condenser
6
InLens SE detector / EsB detector
7
Objective lens
Focuses the electron beam on to the specimen surface.
8
Scanning coils
Deflect the beam across the specimen surface in what is usually referred to as a raster
scan.
9
Specimen
Sup
Suppressor voltage
Extractor voltage
Acceleration voltage
B
Liner tube voltage
30
Instruction Manual ZEISS Crossbeam 350 | en-US | Rev. 3 | 349500-8111-000