FEI Quanta FEG 250, Руководство пользователя

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Software Control: xT microscope Control Software
4-24
Note:
Right-clicking over the 2D box opens the menu with following
particular choices:
• The Reset sets the Beam Shift value to zero and moves the stage
to compensate the resulting image shift (same as the Stage menu
/ Beam Shift Reset function).
5. The Tuning Module
enables a fine electron source alignment, providing the aperture is
mechanically well aligned and a coarse pre-alignment via the Gun
alignment procedure is done.
Note:
The alignment stored by the Gun Alignment procedure (see
Chapter 6) is not overridden by this module control.
The Source Tilt 2D Control
corrects an image illumination drop by changing an efficient angle of
the beam coming from the gun area into the electron column. In the
Crossover mode activated with the button the onscreen image shows
the electron source tip instead of the sample surface.
The Lens Alignment 2D Control
minimizes the objective image shift during focusing. The 2D control
indicates an actual beam position setting relative to the final lens aperture.
The Lens Align. button
starts automatic objective current oscillation (periodically under- and
over focuses the image in a narrow range) to facilitate the process.
Try to bring the rotation center to the screen center (if the
magnification is too high, the rotation could seem like a linear motion
instead of a rotation).
Note:
Right-clicking over the 2D box opens the menu with following
particular choices:
• The Auto Alignment finds optimal conditions automatically.
Note:
The Source Tilt / Auto Alignment is available only for spot sizes 5 or
higher.
6. The Detectors Module
contains continuous adjusters to control the active detector Contrast
(detector voltage) and Brightness (voltage offset). The values are
remembered for each detector and a quad. The adjusters are disabled
if the detector is not available or cannot be controlled (e.g. CCD
camera or an External detector).
The Contrast / Brightness / Enhance Continuous Adjusters
Regardless of the detector actual gain range, the Contrast and
Brightness range is always 0 - 100 (%) and the small / large step size
is 0.1 / 1 (the Brightness step size may differ for some detectors in
order to achieve a sufficient sensitivity). A direct value can be entered
by double-clicking the Contrast / Brightness value. The
Enhance
adjuster (electronic gain) is displayed here or in the Detector Settings
(see the
Preferences… / General tab).
Note:
The label Enhance is truncated because of a space. The full name
should be the Enhanced Contrast .