Revised 03/25/2020
7
f.) Gently allow the holder to slide into the microscope column until it stops. Tap
the end of the holder to make sure it is securely seated.
IV. Emission Current
1.)
In the “Filament” window, set the
“Heat To” value to the desired
cathode temperature (consult the log
sheet for recently used settings). If a
change was made, click the
button
to confirm.
2.)
Click the “Filament” button. It will turn
yellow and the filament will begin
automatically heating to the selected
temperature.
Note: The emission
“Step” setting controls the bias voltage on the Wehnelt cylinder.
A higher step value decreases the bias. This produces more emission current but
increases the energy spread and source size of the beam.
V. Alignment
Note:
Align the microscope from the top (gun) down. Press
F1
at any time for online
help with an alignment. Begin with the
objective and SA apertures removed
. Leave a
condenser aperture inserted
to avoid specimen damage from high beam intensity.
Left control pad (
LC
)
Right control pad (
RC
)
Controls beam shift (trackball),
beam intensity, stigmators, sample
tilt, and multifunction (MF) X.
Controls stage position (trackball),
Z-height,
focus,
magnification,
multifunction (MF) Y, and selecting
diffraction/imaging mode