[ Identification | Description | Input parameters | Links ]

# The `Monochromator_flat` Component

Flat Monochromator crystal with anisotropic mosaic.

## Identification

- Site:
- Author: Kristian Nielsen
- Origin: Risoe
- Date: 1999

## Description

    Flat, infinitely thin mosaic crystal, useful as a monochromator or analyzer.
    For an unrotated monochromator component, the crystal surface lies in the Y-Z
    plane (ie. parallel to the beam).
    The mosaic is anisotropic gaussian, with different FWHMs in the Y and Z
    directions. The scattering vector is perpendicular to the surface.

    Example: Monochromator_flat(zmin=-0.1, zmax=0.1, ymin=-0.1, ymax=0.1, mosaich=30.0, mosaicv=30.0, r0=0.7, Q=1.8734)

    Monochromator lattice parameter
    PG       002 DM=3.355 AA (Highly Oriented Pyrolythic Graphite)
    PG       004 DM=1.677 AA
    Heusler  111 DM=3.362 AA (Cu2MnAl)
    CoFe         DM=1.771 AA (Co0.92Fe0.08)
    Ge       111 DM=3.266 AA
    Ge       311 DM=1.714 AA
    Ge       511 DM=1.089 AA
    Ge       533 DM=0.863 AA
    Si       111 DM=3.135 AA
    Cu       111 DM=2.087 AA
    Cu       002 DM=1.807 AA
    Cu       220 DM=1.278 AA
    Cu       111 DM=2.095 AA

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default |
zmin | m | Lower horizontal (z) bound of crystal | -0.05 |
zmax | m | Upper horizontal (z) bound of crystal | 0.05 |
ymin | m | Lower vertical (y) bound of crystal | -0.05 |
ymax | m | Upper vertical (y) bound of crystal | 0.05 |
zwidth | m | Width of crystal, instead of zmin and zmax | 0 |
yheight | m | Height of crystal, instead of ymin and ymax | 0 |
mosaich | arc minutes | Horizontal mosaic (in z direction) (FWHM) | 30.0 |
mosaicv | arc minutes | Vertical mosaic (in y direction) (FWHM) | 30.0 |
r0 | 1 | Maximum reflectivity | 0.7 |
Q | 1/angstrom | Magnitude of scattering vector | 1.8734 |
DM | AA | monochromator d-spacing, instead of Q = 2*pi/DM | 0 |

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

## Links

- Source code for `Monochromator_flat.comp`.

[ Identification | Description | Input parameters | Links ]