[ Identification | Description | Input parameters | Links ]

# The `Spot_sample` Component

Spot sample.

## Identification

- Site:
- Author: Garrett Granroth
- Origin: Oak Ridge National Laboratory
- Date: 14.11.14

## Description

    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.

Name | Unit | Description | Default |
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 |

AT ( | , | , |  | ) RELATIVE |  |
ROTATED ( | , | , |  | ) RELATIVE |

## Links

- Source code for `Spot_sample.comp`.

[ Identification | Description | Input parameters | Links ]