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McStas: templateDIFF Instrument at Templates

[ Identification | Description | Input parameters | Output parameters | Links ]

The templateDIFF Instrument

Simple monochromator Diffractometer for powders


  • Site: Templates
  • Author: E. Farhi
  • Origin: LLB/ILL
  • Date: 13 Apr 2006
  • Version: $Revision$


A template powder diffractometer used as a tutorial at LLB.
Default geometry is from D20@ILL.

If included after a guide, use ALPHA1=0 and L1=0 (the first collimator is then
the guide with effective ALPHA1=m*0.1*lambda). If you prefer to include 
explicitely a collimator before the monochromator, use L1=1.2.

Monochromator lattice parameter
PG       002 DM=3.355 AA (Highly Oriented Pyrolythic Graphite)
PG       004 DM=1.607 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
lambda Angs Wavelength at monochromator, computed from DM and THETA_M if left as 0. 1
DM Angs d-spacing of monochromator, computed from lambda and THETA_M if left as 0. 3.355
Powder str File name for powder description "Na2Ca3Al2F14.laz"
RV m Monochromator vertical curvature, 0 for flat, -1 for automatic setting -1
L1 m Source-Monochromator distance 17
L2 m Monochromator-Sample distance 3.2
L3 m Sample-Detector distance 1.471
ALPHA1 before monochromator [min] Horizontal collimator divergence for L1 arm 5
ALPHA2 monochromator-sample [min] Horizontal collimator divergence for L2 arm 60
ALPHA3 sample-detector [min] Horizontal collimator divergence for L3 arm 5
ETA gaussian [min] Monochromator horizontal mosaic 12
verbose 1 Print DIF configuration. 0 to be quiet 1
THETA_M deg Monochromator take-off angle, computed from lambda and DM if left as 0. 0
SM 1 Scattering sense of beam from Monochromator. 1:left, -1:right 1


[ Identification | Description | Input parameters | Output parameters | Links ]

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Last Modified: Friday, 17-Mar-2017 21:40:07 CET
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