Schematics of the sample mounts can be found at
We begin by assuming that the microscope is properly aligned and
that all the alignment parameters were set up correctly when
setting up the microscope. The procedure for exchanging a specimen
- Go to Alignment
Edit Alignment Retract specimen.
This will retract ZDET downstream and ZSTG
downstream by 2 mm to be able to safely exchange the sample.
Note that the standard specimen mounting slot on the piezo
stage prevents you from bumping the order sorting aperture (OSA),
which is a nice feature.
- Exchange the specimen. For the inboard branch follow the
instructions to vent the chamber (Sec. 3.3) first.
- Insert the VLM with Alignment
Edit Alignment Detector: Insert
- Open the window Alignment
Align and Focus Sample with VLM (also see
Sec. 5.11). Observe the sample on the VLM
and use the controls in the window which popped up to focus onto
the sample (ZDET) and laterally move it to the desired
position (XSTG, YSTG). If you are inserting
the pinhole remember that you have to move the VLM about
100 m farther upstream to compensate for the thickness of
the pinhole foil.
In principle you could also use the popup windows from the
"Move" menu for the above. In this case, however, you must make
sure to use ZDET (NOT ZSTG!) to get the VLM to
focus on the specimen. The lateral position of the sample has to
be changed with XSTG and YSTG (NOT
XDET and YDET) because you need to adjust the
specimen position relative to the beam!
- Once you have focused on the desired specimen area,
hit Alignment Edit Alignment
Record specimen in VLM focus to indicate to the computer
is in the VLM focus.
- For the inboard branch follow the instructions in Sec. 3.2
to fill the chamber with Helium. During this process the positions of the sample may change
a little, so repeat the previous step afterwards.
- Insert the specimen (Alignment
Edit Alignment Insert specimen)
- Insert the detector of your choice with Alignment
Edit Alignment Detector: Insert XY.
- Insert the specimen again (Alignment
Edit Alignment Insert specimen) to
correct the distance between specimen and detector.
The specimen should now be within about 20 m of the correct
focus position, thanks to the VLM prefocusing.
- Do an overview scan to check that you're on the desired
sample area: Scan Stepper
- Do a focus scan to optimize the x-ray focus on the specimen.
When you have moved into x-ray focus, you must record it with
Alignment Edit Alignment
Record specimen in X-ray focus.
This will ensure that when you change the photon energy, your
specimen will be moved accordingly into the new focus position.
You may record the x-ray focus at any time (i.e., you
can re-focus and re-record the focus later on for a different
- Save the alignment with Alignment
Write Alignment File. You must do this if you want
to exit SM_GUI and run sm_script to take a stack, for