Folding viewing axes in Single Crystal or Diffuse scattering data on DAVE, MSlice

Folding viewing axes in Single Crystal or Diffuse scattering data on DAVE, MSlice

Sometimes, the viewing axes may be folded to make the slice plots more clear and to cover more area in E-Q space. It may be particularly useful if the sample has week signal or lack of enough data to see the features clearly or may be to over come the lack of detector coverage in one particular direction.

In Dave, under  Single Crystal sample types, you will see the under the option viewing axes, "Fold".

• The viewing axes can be folded around a folding center. The auto folding direction is to the side with larger range. 

• Multiple folding centers can be specified in a text box separated by space or comma. 

• Clicking on the direction droplist with multiple folding centers specified will bring up a dialog window for the multiple folding directions. The folding is done in the same order that the centers are specified.

• The projection needs to be recalculated if any of the folding selections is changed.

 Some Examples :

Here are some examples of how to fold the viewing axes.

1. This is a good example of how folding improve quality and cover more area in E-Q space.

 

In this we are going to fold the Plot dispersion along (0.5,2,L). And plot figures with and with out folding. When folding we fold long H at center H=0 and along K center at K =0.

 

 

Above figure shows how to do the folding. To fold along H check the "fold" check box right to the label H. Since we are plotting at H=0.5 we have to fold to + direction. In this case "auto" will work. 2nd Example below will show when to change it. Same is done for K and folded along K.

The figures are as below.

Without folding

With folding - In this, the reciprocal space is folded, about axes other than the dispersion direction. i.e. - along H at center H=0 and along K at center K =0.

2. Here is another example. 

In this case we are plotting the dispersion along (2.5,K,-1). The folding axes need to select carefully. That is since we plot at L = -1, we have to select the direction of L folding as "-".

The results are as below,

Without folding

With folding - In this, the reciprocal space is folded, about axes other than the dispersion direction. i.e. - along H at center H=0 and along L at center L =0.