3 Product and Functional Description | 3.2 Main Components
ZEISS
lect and control the important factors such as acceleration voltage, chamber pressure, and beam
path. The signal-to-noise ratio in variable pressure mode can also be improved via the noise re-
duction features of SmartSEM. For details refer to the Software manual SmartSEM.
Fig. 11: Non-conducting specimen imaged with an acceleration voltage of 20 kV and a 30 μm aperture. Left: High
vacuum (
) mode, showing strong charging effects. The electron beam is distorted and high-quality imaging is not
mode at 21 Pa. Charges are completely compensated, allowing easy imaging of the specimen.
3.2.3 Electron Optical Column | Gemini 1
Purpose
The Gemini 1 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. 12: Schematics of the electron optics
1
Gun
Generates the electron beam.
2
Extractor
Positive electrode that extracts elec-
trons from the filament.
3
Anode aperture
4
Multihole aperture (aperture changer)
5
Condenser
Collects and focuses the electron beam
onto the specimen.
6
InLens SE detector / InLens Duo detec-
tor
32
Instruction Manual ZEISS SIGMA series | en-US | Rev. 7 | 352102-9344-006
