[ Identification | Description | Input parameters | Links ]

The Monochromator_bent Component

A bent crystal monochromator. Mosacity and bending radius can be set.

Identification

• Site:
• Author: Daniel Lomholt Christensen with help from Jan Šaroun
• Origin: ILL / Niels Bohr Institute, University of Copenhagen.
• Date: 24 August 2023

Description

This monochromator is a number of lamella of a perfect crystal.
The lamella are placed in the horizontal plane, behind each other, centered at 0.
The crystal is bent, so that it follows a curve on a cylinder of radius_x.
The monochromator lies along the z plane, so when a diffraction angle of theta
is desired, it should just be inserted in the ROTATED parameter around
the y-axis.
Instruments that showcase the use of this component is the
"Test_monochromator_bent.instr", and the "ILL_SALSA.instr" under the examples folder.
SALSA showcases its complex use in a real instrument, while Test_monochromator_bent
makes a simple show of its capabilities.

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
zwidth	m	Width of each lamella without bending.	0.2
yheight	m	Height of each lamella without bending.	0.1
xthickness	m	Thickness of each lamella without bending.	0.0005
radius_x	m	Radius of the circle the monochromator bends on in the plane.	2
lamella_slabs	1	Amount of horizontal lamella in you monochromator.	1
lamella_gap_size	m	Gap between said horizontal lamella.	0
plane_of_reflection	str	The plane of reflection from the material, e.g. "Si400". The list of possible reflections can can be seen in the source code.	"Si400"
angle_to_cut_horizontal	deg	Angle between cut and normal of crystal slab, horizontally	0
angle_to_cut_vertical	deg	Angle between cut and normal of crystal slab, vertically ! NOTE: This may not work as intended.	0
mosaicity	arcmin	Gaussian mosaicity of the crystal. Always the horizontal mosaicity	30
mosaic_anisotropy	1	Anisotropy of the mosaicity, changes vertical mosaicity to be mosaic_anisotropy*mosaicity	1
domainthickness	1e-6m	Thickness of the crystal domains.	10
temperature	K	Temperature of the monochromator in Kelvin.	300
verbose	1	Verbosity of the monochromator. Used for debugging.	0

AT (	,	,		) RELATIVE		Generate
ROTATED (	,	,		) RELATIVE

Links

• Source code for Monochromator_bent.comp.

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[ Identification | Description | Input parameters | Links ]

Generated on mcstas 3.5.27

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Last Modified: Tuesday, 29-Apr-2025 16:45:07 CEST