Single point X-Y corrections

Making a file with X-Y corrections for polar rotation based on 1 optimized point

Recently this kind of X-Y corrections was integrated directly in the MultiAx software, but you can still use this manual procedure if you have troubles.

Axis of the polar rotation is generally not passing through the sample surface. Because of this during the rotation the sample will move away from the focus of the analyzer (and the beam). This can strongly affect polar maps measured in large angular range, especially for small samples.

Top-view on the manipulator with a sample. X-Y corrections are necessary when rotation axis (white dot) is not on the surface of the sample (red dot).

A way to cope with this problem is to adjust the sample's X/Y position for each new polar angle. To find the correct X,Y for each angle you can first optimize sample position manually for a set of polar angles inside the range of interest and then use them as a reference with interpolation in between (see MultiAx polar corrections tab).

Theoretically it is possible to do good manual optimization only for one point (in the middle of region of interest) and calculate all other X/Y positions based on this point and the position of polar rotation axis.

To do that find the following icon on the desktop:

Icon of Igor experiment

You can also find the file here. This will create polar corrections for +-40 degrees from the point with good optimization and with step of 2 degrees. Press "Save".

Finally in MultiAx Polar corrections tab press Load File button and select the file "XY-correction" (it should be on top if files are sorted by date).

Manual adjustment is best for small or non-uniform samples where precision is important

Automatic adjustment will work best for middle-sized to big uniform samples.