ZEISS
3 Product and Functional Description | 3.2 Main Components
3.2.2 Electron Optical Column | Gemini II
Purpose
The GEMINI II 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
Sup
U
Ext
U
EHT
U
B
1
2
3
4
5
6
7
8
9
10
11
Fig. 9: Schematics of the electron optics
1
Gun
2
Extractor
Positive electrode that extracts electrons from the filament.
3
Anode aperture
4
Upper condenser
5
Single hole aperture
6
Lower condenser
7
8
9
Objective lens
Focuses the electron beam on to the specimen surface.
10
Scanning coils
Deflect the beam across the specimen surface in what is usually referred to as a raster
scan.
11
Specimen
Suppressor voltage
Extractor voltage
EHT
Acceleration voltage
Liner tube voltage
Instruction Manual ZEISS Crossbeam 550L, Crossbeam 550 | en-US | Rev. 3 | 349500-8122-000
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Summary of Contents for Crossbeam 550
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