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McStas: SNS_source Component

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

The SNS_source Component

Modified: G. E. Granroth Nov 2014 Move to Mcstas V2 Modified: J.Y.Y. Lin April 2021 to Fix race condition Modified: P. WIllendrup 2021 Move to Move to Mcstas Version 3 and enable GPus A source that produces a time and energy distribution from the SNS moderator files


  • Author: G. Granroth
  • Origin: SNS Project Oak Ridge National Laboratory
  • Date: July 2004
  • Version:(Unknown)


Produces a time-of-flight spectrum from SNS moderator files
moderator files can be obtained from the SNS website .
IMPORTANT: The output units of this component are N/pulse
IMPORTANT: The component needs a FULL PATH to the source input file
(1) the raw moderator files are per Sr.  The focusing parameters provide the solid
angle accepted by the guide to remove the Sr dependence from the output. Therefore
the best practice is to set focus_xw and focus_yh to the width and height of the next beam
component, respectively. The dist parameter should then be set as the distance
from the moderator to the first component.
(2) This component works purely by interpolation. Therefore be sure that Emin and
Emax are within the limits of the moderator file

WARNING: This is a contributed Component.

Input parameters

Parameters in boldface are required; the others are optional.
Name Unit Description Default
xwidth m width of moderator 0.1
yheight m height of moderator 0.12
dist m Distance from source to the focusing rectangle  
focus_yh m Height of focusing rectangle  
Emin meV minimum energy of neutron to generate  
Emax meV maximum energy of neutron to generate  


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

Generated automatically by McDoc, Peter Willendrup <> / Wed Jan 12 15:13:20 2022

Last Modified: Wednesday, 12-Jan-2022 16:13:20 CET
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