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McStas: Spot_sample

[ Identification | Description | Input parameters | Links ]

The Spot_sample Component

Spot sample.


  • Site:
  • 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)

Input parameters

Parameters in boldface are required; the others are optional.
radius_omOuter radius of sample in (x,z) plane0.01
hmHeight of sample y direction0.05
pack1Packing factor1
xwidthmhoriz. dimension of sample, as a width0
yheightmvert.. dimension of sample, as a height0
zthickmthickness of sample0
EidealmeVThe presumed incident energy100.0
wmeVThe energy transfer of the delta function50.0
two_thetadegreesthe scattering angle of the spot25.0
n_spots1The number of spots to generate symmetrically around the beam4


[ Identification | Description | Input parameters | Links ]

Generated on 2024-01-03 11:47:43

Last Modified: Wednesday, 03-Jan-2024 19:59:11 CET
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