© Steffen Weber, July 1997, (update 10/27/01)
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Film size and Film distance
The Film size is set as 120 x 120 mm. The film-sample-distance (FSD) is
set as 50 mm. Therefore in transmission mode reflections with theta<=25 deg
and in backreflection mode reflections with theta>=65 deg are plotted.
This applet simulates X-ray Diffraction patterns for the Laue method
These Lauegrams are often very useful in determining the orientation
of a crystal sample. You may index the individual reflections by clicking
at them. Here only geometrical relations are
considered without calculating the actual diffraction intensities.
As a very crude (and not always correct) approximation you may choose
the spot radius to be proportional to the spacing d, since the
strongest reflections usually come from the planes with the lowest indices
and the largest d-values. The calculation of the intensities is not
convenient for Applets, since the user must input the contents of the
asymmetric unit cell, which I consider to be cumbersome.
However, I will later release a version which should be copied to your
computer and run as a standalone JAVA Application. In such a case
I can implement file access on your local disc so that the loading
of input files with the cell contents is possible
(as well as PostScript output).
NOTE: I included the search for all equivalent reflections for non-cubic systems. To do so, the actual hkl-loop runs
from -2*max.order to +2*max.order (only for non-cubic case). Please keep that in mind and dont set
maximum order too high, since the calculation might take considerable time. This feature is needed if one wants
to obtain symmetrical patterns.
FOR DOWNLOADING *.class FILES CLICK THE FOLLOWING LINES TO OPEN THEM AND THEN SAVE THEM TO YOUR HARDDISK!
Then modify your *.html file in the same directory by adding the line
< applet code="lauegram.class" width=650 height=530 > </applet >
or just download THIS *.html file.