FEI Quanta FEG 250, Руководство пользователя

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Software Control: xT microscope Control Software
4-23
2. The Column Module
contains controls for setting the electron beam conditions:
The Beam On Button
switches the accelerating voltage on / off. When activated /
deactivated, the button changes from gray to yellow / yellow to grey.
The High Voltage Preset / Continuous Adjuster
enables to adjust the overall electron beam acceleration voltage (from
200 V to 30 kV in 100 V steps) either continuously or using the pre-set
values (see the
Preferences… / Presets tab). The actual High
Voltage value is displayed in the text area of the adjuster, toolbar and
in the Databar (if selected).
The Spot Preset / Continuous Adjuster
enables to adjust the electron beam Spot size, numbered from 1 to 7
(values from 3.9 to 4.0 are disabled) in the selectable accuracy steps
(see the
Preferences… / General tab). The actual spot size number
from the factory preset list is displayed in the text area of the adjuster,
toolbar (default) and in the Databar (if selected).
The Spot number change influences both the focused electron beam
area and the Beam Current. The lower is the Spot number, the lower
is the Beam Current.
3. Magnification / HFW Module
The continuous adjuster offers a variety of ways to control the actual
imaging magnification (see above). The magnification range changes
dynamically according to the working distance and can also be
controlled with the use of other tools (see Chapter 5).
Magnification Control
• Clicking the end arrow increases magnification by about 5% .
• Clicking between the end arrow and the button increases
magnification by about 20% .
The Magnification is possible to display as the Horizontal Field
Width (HFW) alternatively (see the Preferences… / General tab).
4. Beam Module
The Stigmator 2D Control
enables to correct an image astigmatism. The crosshair cursor
indicates the actual setting.
The Shift key + Pressing over an electron imaging quad triggers the
astigmatism correction. Unlike the 2D box control, this is magnification
sensitive and therefore it suits for fine corrections at high
magnifications.
The Beam Shift 2D Control
indicates and controls the beam shift with respect to the objective lens
axis. It is useful for fine image shifts without stage movement.
The Shift key + Pressing over an electron imaging quad triggers the
Beam Shift function. The mouse cursor changes to a hand one that
"holds" the image and drags it over the screen. Because of a limited
Beam Shift range, this works well only for high magnifications.