KSLStrain    

Orientation

An orientation must be specified for each pattern by clicking on “Settings” command button and by selecting “Orientation” tab.

There are two ways to specify the orientation:

1. By providing Euler angles. Their definition is the same as in crystallographic texture analysis (see, e.g. A.Morawiec, Orientations and rotations, Springer, Berlin, 2004), except that the standard in textures is to provide the orientation with respect to the sample coordinate system; here it must be given  with respect to the microscope coordinate system, i.e. tilt angles have no influence on these orientation parameters. The third axis (z) of the microscope coordinate system is perpendicular to the plane of the detector and directed from the detector towards the sample; its first axis is parallel to the horizontal edge of the detector (and to the holder tilt axis). The first angle of the three Euler angles (fi1) corresponds to the rotation about the z-axis of the microscope coordinate system. 

2. By specifying the zone axis parallel to the z-axis of the microscope coordinate system. This is equivalent to providing two of three orientation parameters. The third one  is the rotation about the axis perpendicular to the detector (about the pattern center); it can be determined using the command button marked by a circle in the "Fine-tuning" frame box in the main (KSLStrain) window of the program.

If multiple patterns are used, the orientations must be specified in a consistent way; they must be linked to holder tilts for which they were obtained. The symmetrical equivalence of orientations cannot be used because, with arbitrary strain tensor, the symmetry is broken. For instance, if the zone axes are [001], [011] and [010] (tilt about x), one cannot use [001], [110] and [010] or [001], [011] and [0-10]. The same warning applies to orientations given by Euler angles. If orientations are determined automatically, they will be selected consistently with tilt angles (2deg limit) and orientations of all remaining patterns, if the box located near the "Settings" button is checked. 

Orientation can be fine-tuned using the “arrow and circle” buttons in the “Fine tuning”  frame box.