5 Commissioning and First Operating Steps | 5.8 Working with Variable Pressure
ZEISS
5.8.2.2.1 Inserting the Beamsleeve Aperture
Procedure
1. From the
Menu Bar
, select
Tools > Goto Panel
.
à
The
Panel Configuration Bar
is displayed. It contains an alphabetical list of functions.
2. Double-click
Beamsleeve Alignment
.
à
A window is displayed which shows you an example of a centered beamsleeve aperture.
3. Click
Beamsleeve In
.
à
The beamsleeve aperture is automatically inserted.
5.8.2.2.2 Measuring the Size of the Beamsleeve Aperture
Procedure
1. Take an InLens image of the beamsleeve with a
low magnification at EHT > 5 kV.
2. To display crosshairs, from the
Menu Bar
, select
View > Crosshairs
.
3. In the
Annotation Bar
, click the
Radial Measure
icon and measure the diameter.
5.8.2.2.3 Centering the Beamsleeve Aperture
Procedure
1. Center the beamsleeve aperture with the help of the x- and y-alignment knobs at the
beamsleeve mechanic behind the microscope.
2. In the
Beamsleeve Alignment
window, click
Beamsleeve Out
.
à
The beamsleeve aperture is retracted.
3. Click
Beamsleeve In
to insert the beamsleeve aperture again.
4. Check the alignment of the inserted beamsleeve aperture again.
You will observe that the aperture is not centered anymore. This is due to friction that oc-
curs during insertion.
5. Use the x- and y-alignment knobs again: Align the beamsleeve aperture in a way so that it
will be centered after the next insertion.
6. Retract and insert the beamsleeve aperture again and check that it is correctly centered.
à
If the aperture is centered after the insertion, then it is correctly aligned.
7. Close the
Beamsleeve Alignment
window.
5.8.2.3 Ideal Working Conditions in Nano VP or XVP Mode
When you work in Nano VP you have to control three bias voltages:
§
Beamsleeve bias
§
§
EsB grid
The EsB grid does not influence other detectors, but beamsleeve bias and VPSE/C2D collector bias
influence each other. When beamsleeve bias is on, gas cascade electrons are guided into the col-
umn and can therefore not be detected by the VPSE/C2D detector. Beamsleeve bias may limit
your VPSE/C2D detector efficiency.
In case you would like to optimize VPSE/C2D efficiency, set the beamsleeve bias to 0 V.
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Instruction Manual ZEISS GeminiSEM series | en-US | Rev. 2 | 349500-8138-000