Spot sample.
Author: Garrett Granroth
Origin: Oak Ridge National Laboratory
Date: 14.11.14
A sample that is a series of delta functions in omega and Q. The Q is determined by a two theta value and an equal number of spots around the beam center. This component is a variation of the V sample written by Kim Lefmann and Kristian Nielsen. The following text comes from their original component. A Double-cylinder shaped incoherent scatterer (a V-sample) No multiple scattering. Absorbtion included. The shape of the sample may be a box with dimensions xwidth, yheight, zthick. The area to scatter to is a disk of radius ’focus_r’ situated at the target. This target area may also be rectangular if specified focus_xw and focus_yh or focus_aw and focus_ah, respectively in meters and degrees. The target itself is either situated according to given coordinates (x,y,z), or setting the relative target_index of the component to focus at (next is +1). This target position will be set to its AT position. When targeting to centered components, such as spheres or cylinders, define an Arm component where to focus at.
Example: spot_sample(radius_o=0.01, h=0.05, pack = 1, xwidth=0, yheight=0, zthick=0, Eideal=100.0,w=50.0,two_theta=25.0,n_spots=4)
Parameters in boldface are required; the others are optional.
|
Name |
Unit |
Description |
Default |
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radius_o |
m |
Outer radius of sample in (x,z) plane |
0.01 |
|
h |
m |
Height of sample y direction |
0.05 |
|
pack |
1 |
Packing factor |
1 |
|
xwidth |
m |
horiz. dimension of sample, as a width |
0 |
|
yheight |
m |
vert.. dimension of sample, as a height |
0 |
|
zthick |
m |
thickness of sample |
0 |
|
Eideal |
meV |
The presumed incident energy |
100.0 |
|
w |
meV |
The energy transfer of the delta function |
50.0 |
|
two_theta |
degrees |
the scattering angle of the spot |
25.0 |
|
n_spots |
1 |
The number of spots to generate symmetrically around the beam |
4 |
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Component source code found in file Spot_sample.comp.