SPECS 2D-CCD, Руководство пользователя

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Manual V2.docx | Status 10.12.2015 | Version 1.0
A.5 Camera alignment
It is essential to have a correctly aligned camera with a CCD detector. The camera alignment
affects the energy resolution, angular resolution and sensitivity.
When baking out the analyzer, you need to remove the camera. After remounting the
camera, you should check the camera image in CCD Acquire to make sure that the alignment
is correct. If the image is not "perfect" (see, e.g. Figure 56 for a correctly aligned camera),
you need to follow the steps in this section to align the camera.
The alignment is easiest if you have an electron gun as an excitation source. This has a high
intensity and is easily variable (in energy and intensity). Electron guns frequently have a
steerable beam, so that you can change the spot position, maximizing the observed signal.
Using an X-ray source to produce photoelectrons is also possible, but the alignment is
slightly more difficult.
The overall procedure involves the following steps:
•
Rough adjustment of the camera angular setting.
•
Changing the Z setting for the focus.
•
Correcting the X–Y position.
•
Fine-tuning of the angle.
Some of these steps may not be necessary. For the initial alignment, we recommend that
you follow the sequence of steps outlined above. Note that during the alignment, you may
find that you need to perform some iteration to get the best results.
A.5.1 Rough angle adjustment
The first stage of camera alignment is to roughly set the camera angle. This is essentially the
mounting position of the camera itself inside the holder.
This initial camera positioning is performed by SPECS—you will only need to perform these
steps if you remove the camera from the holder. As such, this is not a "routine" procedure
that needs to be performed each time you mount the camera on the detector. If you obtain
an image such as that seen in Figure 52, you can skip these steps and move to the next
section.
To set the rough angular position:
1. Loosen the ring nut on the top of the holder using a spanner wrench (pin spanner)
or similar tool.